Biology Final Exam
Study Guide
By Preeya
Be sure to understand the questions and not just memorize the answers. And go over it a few times.
Also, if you print it out, double side it and print in fastdraft and grayscale and then recycle it when you’re done!!
Special thanks to Ruchi, who sent me the Genetics of Viruses & Bacteria, and Jacob and Kevin L. for compiling the Genetics of Viruses & Bacteria.
And of course, best of luck!!
1. Explain the lytic cycle.
a. The Phage binds to receptors on a host cell and injects its DNA.
b. Phage DNA is replicated, and proteins are synthesized to form more phages.
c. The cell lyses, releasing phages
2. How is the lysogenic cycle different from the lytic cycle?
The Lysogenic cycle doesn't end in the death of the host cell.
3. Describe what binary fission is and how similar is it to mitosis.
Asexual reproduction in bacteria in which two origins would be there, in which two daughter cells is created from one cell. It is related to mitosis by the fact that both split one cell into two and that they would have two centrosomes (eukaryotic) and origins (prokaryotic) in which they would hold together the genetic information before replication.
4. Why is transformation, transduction, and conjugation needed in prokaryotic cells?
It is needed to bring in DNA from two individuals in one cell.
5. What are the two routes of plant viruses and explain them.
a. Horizontal transmission - when a plant is infected from an external source of a virus.
b. Vertical transmission - when a plant inherits a viral infection from a parent.
1. What is recombinant DNA?
a. DNA with a high recombination frequency
b. DNA made from a combination of two or more species'
c. DNA Rearranged
d. DNA of one species
e. DNA if it is read backwards
2. What is an expression vector?
A cloning vector with a highly active prokaryotic promoter that can link to a eukaryotic gene.
3. Describe the process of southern blotting.
BOOK [process is word from word…page after 20.2 ends]
4. The repressor molecule attaches to what part of an operon?
The promoter
5. Is the operon responsible for tryptophan synthesis in E. coli cells an example of an inducible or repressible operon?
Repressible
6. What are the three parts to an operon?
a. Promoter, mRNA, Tryptophan
b. Operator, Metabolic Pathway, Enzymes
c. Operator, Promoter, Controlled genes (DNA Strand)
d. Repressor, regulatory gene, operator
e. There are only two parts to an operon
7. What is the function of a repressor? (hint not answer a)
a. To repress things
b. Binds to the operator and prevents RNA polymerase from attaching to the promoter
c. Prevents the regulatory gene from being expressed
d. Restricts enzyme movement
8. The regulatory gene produces what?
a. Repressors
b. Operons
c. Operators
d. None of the above
9. How does Gel electrophoresis separate nucleic acids or proteins by size?
Those molecules have negative charges travel to the positive charge in an electric field and the thicket of polymer fibers slows down the longer molecules.
10. What are the 3 steps involved in the PCR?
Denaturize DNA strands with heat, cool the strands to allow primers to form hydrogen bonds, use DNA polymerase to extend the strands. (Like in DNA replication)
1. Find the distance between two genes if:
You cross aaBb X AaBB and your results are:
50 AaBB
35 aaBb
72 aBb ß you forgot a gene…
94 aabb
Answer: 66 cM
2. What are the three stages of the Human Genome Project?
a. Genetic Mapping
b. Physical Mapping
c. DNA Sequencing
3. What was the name of Vincent Craig’s project? What was its importance?
Celera Genetics. It developed 90% of the human genome over a span of three years.
4. How do scientists determine the function of a gene through genome sequencing and comparative analysis?
They disable the gene and observe the consequences in the cell or organism.
5. What is in vitro mutagenesis?
It is a process in which specific mutations are introduced into the sequence of the cloned gene.
6. What is the Human Genome Project?
A project to find out the DNA sequences and genes of the human chromosomes
7. What are the 3 stages in Genome Mapping?
a. Linkage Mapping
b. Physical Mapping
c. DNA sequencing
8. What is Genomics?
The study of genes and their interactions
9. What are 2 process used to determine a gene function? Describe them.
a. In vitro Mutagenesis: Mutate gene to find out how it affects the cell when the gene is absent
b. RNA interference (RNAi): Break down and block mRNA of a particular gene to see how it affects the cell
10. Why should we compare genomes of different species?
a. Determine evolutionary relationships b/w species
b. Observe simple organisms to understand complex ones
c. Compare 2 related species to obtain genomes – use one a guide to complete the other genome
d. Determine genome functions – a gene that produces a polypeptide in one species, might produce the same polypeptide in another gene
1. How do PCRs help in early detection of diseases?
They are used to amplify the disease causing alleles in Vitro and help in early detection.
2. How has gene therapy affected SCID patients in the past?
In studies they’ve helped SCID patients to produce the genes for the proteins they are missing, yet for other patients, they used retro-viral vectors which gave them leukemia.
3. What are the three shapes of Prokaryotes?
a. Spherical (cocci),
b. rod-shaped (bacilli),
c. spiral.
4. How are Gram Positive/Negative bacterias different?
Gram Positive bacteria have a simple cell wall, while Gram Negative have more complex cell walls.
5. Name 2 uses for RFLPs.
a. In forensics, to identify key points in the genome to compare between 2 DNA samples.
b. In medicine, used as markers for detecting diseases.
1. What is the relationship between a large organism and a smaller symbiote that hurts the larger organism and takes advantage of it?
Parasitism
2. What are common places where crenarchaeotes found?
Hot springs and places in extreme climates
3. What are the 5 groups of proteobacteria?
a. Alpha
b. Beta
c. Gamma
d. Delta
e. Epsilon
4. What is an excellent example of a heterotroph?
Chuck Norris
5. Explain the 2 types of toxins.
a. Endo toxins are proteins that are released when cells die or rupture
b. Exotoxins are proteins that slowly ooze into their environment
6. What is a halophile? {Hint, its not Pronoy}
A bacteria that thrives in extremely salty environments
7. What are extremophiles?
“Lovers of the extreme”
Whatever group Alyssa is in….
- Explain Adolf’s experiment.
He discovered that he could transmit the tobacco mosaic disease from plant to plant by rubbing the infected sap on to healthy ones and concluded that to disease was cause by small bacteria that no one can see.
- What is a viral envelope and give an example.
- An animal virus equipped with and outer membrane and uses it to enter the host cell
- Herpesviruses
- What is a provirus?
- The integrated viral DNA
- Never leaves the host’s genome, remaining a permanent resident of the cell
What was the significance of the “Origin of Species by Mans of Natural Selection”?
(By Charles Darwin)
--It brought biologist attention to the diversity of organisms
What were the two points made in OoS?
- Presented evidence that organisms of earth descended from ancestral species that were different from modern species
- Natural selection – Mechanism for evolutionary process, in which the basic idea is that population can change over generations if individuals that posses certain heritable traits leave more offspring than other individuals.
Compare gradualism against uniformitarianism.
Gradualism stated that change takes place through a slow and continuous process while uniformitarianism states that change happens in big steps at a time.
What was Lamarck’s theory?
The theory of use and disuse, in which body parts which you use grow stronger and more dignified, while things you do not use so much start to fade away.
Who came up with taxonomical classification, and what was it?
Linnaeus;
Kingdom > Phylum > Class > Order > Family > Genus > Species
[Memory Gem! I use – King Paul came over for good spaghetti]
What were the 2 main ideas Darwin had developed?
- Evolution explains life’s unity (all organisms are connected)
- Diversity and natural selection is the cause of adaptive evolution
______ is another word for natural selection.
-- Descent with modification
What were some of Ernest Mayr’s observations?
•Exponential population growth shall occur if all individual organims reproduce successfully
•Populations tend to stay stable in size
•Resources are limited therefore more individuals are produce, than do survive–SO, more
•Members of a pop vary
•Variation is mostly variable
Define selection pressure.
The intensity with which an environment tends to eliminate an organism, and thus its genes, or to give it an adaptive advantage
Why doesn’t natural selections create perfect beings?
- It is editing, not selecting
- Individuals do not evolve, only populations do
- Natural selection only can amplify or diminish heritable traits , not create new ones
Name some vestigial structures
--Leg bones in whales and snakes
What is population genetics?
Population genetics is the study of allele behavior in populations
What is a population?
A population is a group of interbreeding individuals of single species
Compare microevolution to macroevolution –
Microevolution – changes in the allelic frequencies of a single gene pool.
Macroevolution – evolutionary change above the species level.
Compare anagenesis to cladogenesis
Anagenesis is the accumulation of heritable changes, altering the characteristics of a species. Cladogenesis is branching evolution, in which a new species arises from a population that buds from a parent species. Cladogenesis is the basis for biological diversity.
(Below anagenesis is on the left, while cladogenesis is on the left)
Compare allopatric speciation to sympatric speciation.
Allopatric speciation – When a species splits in two due to geographical isolation
Sympatric speciation – When a species splits in two due to behavioral isolation
What is reproductive isolation?
Any factor that prevents 2 species from producing fertile offspring
What are the two types of reproductive isolation?
Prezygotic – Barriers hindering mating or hindering fertilization of mating does occur
- Habitat Isolation – barrier of physical area
- Temporal Isolation – barrier of different breeding times
- Behavioral Isolation – barrier of different courtship rituals
- Mechanical Isolation – barrier of physical appearance
- Gametic Isolation – barrier of lack of proper reproductive parts
Postzygotic – Prevents a hybrid zygote from developing into a viable, fertile adult
Reduced Hybrid Viability – When intergenus breeding makes the offspring frail
Reduced Hybrid Fertility – When interspecies breeding makes the offspring sterile
Hybrid Breakdown (sterile grandchildren) – When First Generation hybrids mate with one another and the offspring becomes sterile or feeble.
___________ is allopolyploid hybrids that cannot mate with either parent species.
--Polyploidy
Name two sexual selection hypotheses.
· Good Genes Hypothesis
· Sexy Sons Hypothesis
Compare gradualism to punctuated equilibrium.
Gradualism is when species descended from a common ancestor gradually diverge more and more, while punctuated equilibrium is when new species changes most as it buds from a parent species and then changes little for the rest of its existence
What is the Hardy-Weinburg formula and what are its conditions?
p2 + 2pq + q2 = 1
If p = frequency of allele A = 0.9
• And q = frequency of allele a = 0.1
• Then AA + 2Aa + aa = 1 would be
p2 + 2pq + q2 = 1
• From the above example p = 0.9, and
q = 0.1
• (0.9)2 + 2(0.9)(0.1) + (0.1)2 = 1
• 0.81 + 0.18 + 0.01 = 1
Conditions:
The population must be large
• Mutations must not occur
• There must be no immigration or
emigration
• Reproduction must be random
• There must be no natural selection
Define:
Bottleneck effect – when gene pool is no longer reflective of original populations gene pool due to sudden change in environment
Founder effect – When few individuals become isolated from larger population and smaller group establishes a new population whose traits are not reflective of source population
What is directional selection?
When a population’s environment changes or when members of a population migrate to a new habitat with different environmental conditions than their former ones causing gene pools to change.
Top: Original Population
Left: Directional Selection – shifts overall makeup of population by favoring extreme end
Middle: Disruptive Selection – favors variants at both ends, but not intermediate variants
Right: Stabilizing Selection – removes extreme variants and preserves the intermediate types
What is phylogeny?
--An evolutionary history of species or a group of species
What is systematics?
A way to understand the related diversity of organisms
What is taxonomy?
The ordered division of organisms into categories
Kingdom > Phylum > Class > Order > Family > Genus > Species
Memory Gem! I use:
King Paul Came Over For Good Spaghetti
What are cladograms?
Cladograms show patterns of shared characteristics of clades, which are a group of species that includes ancestor and all descendants. Shared characteristics connecting different species may include hair, four legs, amniotic egg…et cetera. 
What are the four main eras?
–Neoproterozoic (early worms)
–Paleozoic (542 M yrs to 251 M yrs)
–Mesozoic (251 to 65.5M)
–Cenozoic (65.5 to present)
What are the two types of symmetry that animals can have?
--Radial Symmetry and Bilateral Symmetry
Define the following: ectoderm, endoderm, mesoderm.
Ectoderm – outside covering
Endoderm – lines digestive tract
Mesoderm – lines muscles and other organs
Differentiate between Acoelomates, Pseudocoelomates and Coelomates.
Acoelomates – animals with no coelome (body cavity) EX: Platyhelmenthyes
Pseudocoelomates – animals that have a pseudocoelome EX: Rotifera and Nematoda
Coelomates – animals with a true coelome
In _________, the mouth develops from blastopores
--Protostomes
In _________, the anus develops from blastopores
--In deuterostomes
Explain radial symmetry
Radial symmetry occurs in animals, when, if compared to a pie, and cut into equal slices, all slices would be identical.
What are some characteristics of sponges?
-- Sponges are sessile suspension feeders (capture food particles suspended in water that pass through their body)
Trace the path water takes through the sponges body.
-- Pores à Spongocoel à Osculum
Define the functions of the mesohyl, osculum, spongocoel, chanocytes, and amoebocyes, and locate them on the picture below.
Spongocoel – Central Cavity that water goes through, then flows out thorough the oscuculum (larger central opening)
Choanocytes – It lines the spongocoel with flagellelated collar cells which generate current to trap food which gets ingested by phagocytosis.
Mesohyl – Gelatinous region of sponge
Amboebocytes – In Mesohyl; Takes up food from choanocytes, digest its, and carries nutrients back to the other cells & makes tough skeletal fiber.
Porocytes – Used for pore support.
Explain reproduction in sponges.
--Sponges are hermaphrodites (produce both sperm and egg) and gametes are produced in choanocytes or amoebas & cross-fertilized though currents occur. Eggs are produced in Mesohyl.
Describe Phylum Cnidaria.
Cnidarians have a radial body plan and they can be sessile or floating; They have a radial body plan, gastrovascular cavity which serves as its digestive compartment, and are carnivorous. Cnidarians use their tentacles to capture prey and ingest undigested bites through mouth/anus, and their tentacles contain cnidocytes which contain nematocysts, which are needles of stinging.
Compare and contrast the body plan of Cnidarians [Polyps vs Medusa], using the picture below:
The Polyp Body Plan – Includes hydras & sea anemones, and have cylindrical forms that adhere to the substrate by aboral end of the body (opposite of mouth) and extend tentacles, waiting for prey.
The Medusa Body Plan – Includes Jellyfish; Moves freely in water by combo for passive drifting and contractions of bell-shaped body.
What are the four classes of Cnidarians? Describe them.
Pneumonic Device: Use the acronym CASH
Cubozoans – They are marine, with a box-like medusa shape with complex eyes.
EX: Box jellies & sea wasps
Anthozoans – Only polyps, mostly sessile, and mainly colonial
EX: Coral (made of calcium carbonate)
Scyphozoans – Mostly medusas, with small polyp stages and free swimming
EX: Sea jellies
Hydrozoans – Alternate between polyp and medusa forms while the polyp stage is colonial. They are mostly marine while few are freshwater, and they reproduce by budding.
EX: Portuguese Man-of-War, Hydra
Acoelomates
Differentiate between Acoelomates, Pseudocoelomates and Coelomates.
Acoelomates – animals with no coelome (body cavity) EX: Platyhelmenthyes
Pseudocoelomates – animals that have a pseudocoelome EX: Rotifera and Nematoda
Coelomates – animals with a true coelome
Phylum Platyheminthes
Describe Phylum Platyhemithes.
Include flatworms who live in marine, freshwater, and damp terrestrial habitats. They include flukes & tapeworms.
Bodies of Platyhemintheyans are thin between dorsal and ventral surfaces. They undergo triploblastic development, but lack a body cavity (though have a GVC) and have no organs for gas exchange or circulation, so it is their shape that makes gas exchange and elimination of nitrogenous waste easy by diffusion and possible.
List the 4 classes of Platyheminthes.
- Turbellarian (Free Living Flatworms) EX: Dugesia
- Monogena (Monogeneans)
- Tremataoda (flukes)
- Cestoda (tapeworms)
Describe the class of Turbellarians
-- Turbellarians are all free living and mostly marine; They move by the cilia, glide using mucus, or use muscle to swim. Their head is armed with light-sensitive eyespots and they have lateral flaps that function to detect chemicals. They reproduce sexually or asexually.
Familiarize yourself with this picture:
Compare the Monogeneans & Trematodes
-- Both live as parasites with suckers and a though covering. They reproduce sexually and asexually
Describe the Trematoda class.
-- Trematodes require an intermediate host where larvae develop before infecting the final host. Trematodes mimic surface blood proteins to get inside humans, and they are parasites with 2 suckers.
Depict the possible journey a Trematodan fluke can take through its host’s body
Describe the Monogenea class.
-- Monogeneans are external parasites of fish; Their life cycle is simple, with a ciliated free swimming larva that initiates the infection on a host.
Describe Class Cestoda.
Cestodans are parasitic tapeworms who live inside humans with an anterior end that is armed with suckers and hooks that lock the worm to the intestinal lining. They absorb nutrients released by digestion in host’s intestine and lack a gastrovascular cavity. Mature proglotids (egg sacs) are loaded with thousands of eggs, released from the posterior end in the host feces.
Pseudocoelomates
Explain some characteristics of Pseudocoelomates.
Pseudocoelomates include Phylum Rotifera and Phylum Nematoda. Pseudocoelomates have no muscle & mesoderm around their digestive tract and they are not segmented.
Describe some characteristics of Phylum Rotifera.
Rotifers live in a moist environment. They are multicellular, but microscopic and have an alimentary canal (digestive tube with mouth and anus). Their internal organs lie within the pseudocoelome and the fluid in the pseudocoelome circulates nutrients and waste. They draw in a vortex of water though their mouth, and they use “pharynx bear claws” to grind up food. Also, some rotifers can reproduce with only females.
Describe some characteristics of Phylum Nematoda.
They have a non-segmented pseudocoelome and an “exoskeleton” of cuticle.
Coelomates
What are advantages to a coelome?
· Internal organs have room for growth
- Fluid of the circulatory system acts as a transport system
- Presence of a hydrostatic skeleton (muscles can squeeze fluid)
Lophophorates
What are Lophophorates?
-- They are sessile suspension feeding creatures that include three phyla – Ectoprocta, Phoronida, and Brachiopoda. They are all identified by a horseshoe-shaped, ciliated crown of tentacles around the mouth (the lophophore) which traps suspended food particles. They have a U-shaped alimentary canal, absence of a head, and a true coelum lined with mesoderm.
List and explain the three phyla of lophophorates
Ectoprocts – Colonial with a hard exoskeleton with pores. They are reef-builders.
Phoronids – Tube dwelling marine worms, who live buried in sand in tubes of chitin.
Brachiopods – They resemble clams (superficially, of course) and have 2 halves of their shell that are dorsal & ventral rather than lateral. 
Describe Phylum Nemertea.
--Nemerteans are proboscis ribbon worms. They have acoelomate, BUT they have a fluid-filled sac, which may be a reduced coelome. The sac & fluid can help extend a proboscis that can inject toxins to prey. They are almost all marine, they swim OR burrow and as far as anatomy goes, they have an alimentary canal and a closed circulatory system. However, they do not have a heart; blood is propelled by muscles squeezing vessels.
Phylum Mollusca
Explain some characteristics of Phylum Mollusca.
-- Phylum Mollusca includes snails, oysters, and octopi. They are soft-bodied creatures with hard shells of calcium carbonate. Some evolved with only an internal shell.
What are the 3 main parts of a mollusk?
- Visceral mass (most organs)
- Mantle (folds of tissue over mass that secretes shell)
- Muscular Foot (for locomotion)
Describe the anatomy of mollusks.
In many mollusks, the mantle extends beyond the visceral mass, producing a mantle cavity, housing gills, the anus, and excretory pores. The radula is an organ used to scrape up food and Gonads are the ovaries or testes.
What are some characteristics of chitons?
--They have a shell with 8 dorsal plates and an oval shaped body; their foot is used for locomotion and grip and they have a radula but no head.
Gastropods make up _____ percentage of all mollusks.
--75%
What is torsion?
-- As the embryo develops, visceral mass rotates up to 180 degrees, causing the anus and mantle cavity to wind up above its head. Then, some organs are lost, or reduced in size.
Explain some characteristics of Bivalvians.
Most Bivalves are suspension feeders; they have gills in the mantle for feeding and gas exchange, and some have eyes and tentacles. However, none of them have a head, and their radula is lost. Two halves hinge them at the dorsal line. Clams, oysters, and mussels are included in the Bivalvian class.
Identify the foot, gills, anus, mantle, and excurrent & incurrent siphon in the picture below.
Describe some characteristics of Cephalopods.
Cephalopods are active predators and include squids, and octopi. They have tentacles and beak-like jaws, as well as a shelled nautilus. Their mantle covers their visceral mass, and they have a closed circulatory system with well-developed sense organs such as a complex brain.
Define ammonites
Ammonites – shelled cephalopods
Phylum Annelida – true coelome and segmentation
What are the 3 classes to Phylum Annelida?
- Oligochaeta
- Polychaeta
- Hirudinea
Identify the:
- mouth
pharyngeal region - seminal receptacle
- seminal vesicle
- crop
- gizzard
- septum
- intestine
Describe some characteristics of Oligochaetes.
-- Oligochaetes include earthworms, whom eat their way through soil and are hermaphrodites and can reproduce asexually (through fragmentation).
Describe some characteristics of Polychaetes.
--Polychaetes include featherfans and have parapodia, which function in locomotion and may serve as gills.
Describe some characteristics of Hirudinea.
Hirudinea include leeches; Leeches may be terrestrial or marine and are parasitic to humans, with their blade-like jaws.
Describe some characteristics of arthropods.
-- Arthropods have many specialized appendages for a variety of purposes. The exoskeleton is made out protein and chitin that is very hard and durable. Arthropods mold and by molting, arthropods prevent desiccation. They also have developed sensory organs, most of which are at the anterior end. Arthropods have an open circulatory system; A fluid called hemolymph is pushed through arteries through sinuses, when it then re-enters the heart.
What are the 4 major lineages of arthropods?
- Cheliceriformes (ticks, spiders, horseshoe crabs…)
- Myriapods (centipedes & millipedes)
- Hexapods (insects)
- Crustaceans (crabs, lobsters, shrimps, barnacles)
What are some characteristics of subphylum Cheliceriformes?
-- They have pinchers, fangs, and appendages that they use for defense. In fact, they have 6 pairs of appendages, and 4 pairs of walking legs. Also, Cheliceriformes have an anterior cephalothorax and posterior abdomen.
________ are what ticks use for sensing and feeding.
-- Pedipelps
What do spiders use for gas exchange, and why is this important?
-- Spiders use book lungs, which are beneficial due to good surface area-volume ratio of the spider’s innards.
What are chelicerae used for?
They are pointed appendages used to grasp food.
Familiarized yourself with the drawing below, and locate the heart, lungs, eyes, chelicerae, and trachea.
Using the drawing below, locate the eye, chelicara, abdomen, telson, and genital operculum.
oa
Describe some characteristics of subphylum Myriapoda.
Subphylum Myriapoda includes millipedes and centipedes. These animals are terrestrial and have mandibles, which are antennae and mouthparts from appendages. Millipede trunks are segmented and they feed on dying organic matter, while centipedes are carnivorous and poisonous.
What are the three major body parts of Hexapodans?
Explain excretion in Hexapods.
Excretion occurs from Malpighian tubules, and they remove nitrogenous waste from hemolymph. Out pockets of digestive tract come in contact with the hemolymph, where diffusion of wastes and water travels through the Malpighian tubules. Water is reabsorbed, and nitrogenous wastes exit.
Describe the general anatomy of Hexapods.
The hexapodan nervous system includes a pair of ventral nerve chords with several ganglia dispersed throughout the body. Mouthparts come from appendages. The heart drives hemolymph through an open circulatory system. The cerebral ganglion is the brain where the 2 nerve chords meet.
Using the drawing above, identify the esophagus, crop, anus, intestine, heart, ganglia, and mid gut.
True or False:
Wings are extended appendages.
--False. Wings are extended CUTICLE, and because of this, insects are coordinated and balanced when not using their wings (1-2 pairs)
What is the difference between complete and incomplete metamorphosis?
-- Incomplete metamorphosis is when the nymph looks like a larger version of the adult after growing, and complete metamorphosis is when the nymph looks completely different from the adult (EX: Caterpillar à Butterfly).
What is reproduction like in hexapods?
-- They have separate males and females, in which the males attract the females with color, sound, and odor. They undergo internal fertilization and females have a spermatheca, which stores sperm.
Familiarize yourself with the drawing below –
Explain some characteristics of sub-phylum Crustacea
Most crustaceans are marine or freshwater. They have branched appendages that are specialized with two pairs of antennae. Appendages are on the abdomen and thorax and can easily be regenerated.
Describe gas exchange, excretion, growth, and blood circulation for Crustaceans.
-- Gas exchanges across thin areas of exoskeleton, or with gills, and nitrogenous waste diffuses across the cuticle; pair of glands regulates hemolymph, and most aquatic crustaceans have one or more swimming larval stages.
What are the four main lineages of crustaceans?
- Isopods (pill bugs)
- Decapods (crabs, lobsters, shrimp)
- Copepods (krill)
- Barnacles (they have a calcium carbonate shell, adhesive appendages for grasping, and some are parasitic)
What are some characteristics of Phylum Echinodermata?
-- Echinoderamatans are slow or sessile marine creatures with spiny skin from skeletal bumps & spines and an endoskeleton of calcium carbonate.
What is a water vascular system?
Water Vascular System – A net of hydraulic canals branching into tube feet for gas exchange, locomotion, and feeding.
Identify the central disk, madreporites, ring canal, tube feet, and ampulla.
Describe some anatomical functions of the Echinodermata Phylum.
--Anatomy of starfish is very interesting. It includes a central disk which contains a nerve ring, a water vascular system which includes a ring canal (central disk) and 5 radial canal that runs down each arm. The radial canal has hundreds of hollow and muscular tube feet, including ampulla, which squeezes water into the podium but an expasion and contraction substrate.
Define the functions of the madreporite, spines, and gills.
Madreporite – allows water in and out of vascular system
Spines – serve as protection
Gills – provide gas exchange
What are the 6 classes of Phylum Echinodermata?
- Asteroidea(starfish)
- Ophiurodea (brittle stars)
- Echinoidea (sea urchins and sea dollars)
- Crinoidea (sea lillies and feather stars)
- Holothuroidea (sea cucumbers)
- Concentricycloidea (sea daisies)
Describe some characteristics of starfish
--Starfish have multiple arms with tube feet that act as suction cups as the grasp rocks, and when hunting – prey.
Describe some characteristics of brittle stars
-- Brittle star arms emerge from a central disk, and they do not use tube feet for gripping, so they move by swishing their arms out; They can be suspension feeders or predators.
Describe some characteristics of sea urchins and sea dollars
-- Sea urchins and dollars have no arms, but they do have 5 rows of tube feet which insure slow movement. Urchin use muscles to pivot out long spines for locomotion and mouth is surrounded by jaw-like structure for feeding.
Describe some characteristics of sea lilies and feather stars
--They are both suspension feeders; Sea lilies are attached to the stalk while feather stars can crawl.
Describe some characteristics of sea cucumbers
--Sea cucumbers are elongated, have a reduced endoskeleton, no spine, and 5 rows of tube feet.
Describe some characteristics of sea daises.
-- Sea daises are armless and disk-shaped with 5 fold symmetry and spines.
Vertebrates I
*Phylum – Chordata; Vertebrates are a sub-phylum.
What are the four major characteristics of vertebrates?
a.) Notochord – A longitudal chord located between the digestive tube and nerve chord, serving as skeletal support.
b.) Dorsal & Hollow Nerve Chord – Central nervous system, that later evolves into a complex brain
c.) Pharyngeal Slits – Used for gas exchange
d.) Post-anal Tail – Used as a propelling force to move through water
Urochordata & Cephalochordata
Tunicates & Lancelets
What two invertebrate groups are included in Chordata?
-- Urochordata and Cephalochordata.
(Be sure to list examples of both)
Explain the metamorphic cycle of Tunicates (Subphylum Urochordata).
--Tunicate larva uses its tail muscles to swim through water and join the substrate. Metamorphosis occurs when the larva joins the substrate
Changes: Tail and notochord are reabsorbed, nervous system is gone and organs rotate 90 degrees.
Explain the feeding process in Lancelets (Subphylum Cephalochordata)
--Lancelets feed on plankton by upward swimming and passive sinking when they swim backwards into the sand. Then, mucus net is secreted across pharyngeal slits that remove the food particles from seawater drawn into the mouth by cilary pumping that lead into intestine.
Explain gas exchange in Lancelets.
-- Diffusion across exterior.
How do lancelets swim?
--Lancelets swim by upward swimming and passive sinking and swimming, by contraction of serially arranged muscles, like rows of chevrons (> > > > >) adjacent to the notochord contract and flexe in a side to side motion. (Somite)
When do lancelets metamorphosize into adults?
--When their anterior end is exposed; (It is otherwise buried into the sand). The traits that they have in larval stages, they retain as adults.
Identify the mouth, pharyngeal slits, notochord, intestine, segmented muscles, and anus in the picture below:
What did Hox genes lead to in Lancelets?
--Development of forebrain, midbrain, and hindbrain in vertebrates.
Craniates
Describe some characteristics of Craniates.
-- Craniates are chordates with:
v A Head & Brain at the anterior end (active predation)
v Hox Genes (2 clusters)
v A Natural Crest (a collection of cells that appear in the embryo near margin of closing *A Neural Tube, giving rise to cheek bones, teeth, and parts of the eyes)
v Gill Slits (evolved from pharyngeal clefts for aquatic craniates); Gill slits were used for…
Aquatic – muscles, nerves, sucking food and gas exchange
Terrestrial – gave rise to formation of other structures
Explain the digestive system and excretory system of Craniates.
-- Craniates have higher metabolism than lancelets and tunicates and more muscle. Muscles line the digestive tract and aid digestion by pushing food through the tract. They also have kidneys for proper waste removal.
Describe the circulatory system of Craniates.
--Craniates have a heart with at least two chambers, red blood cells and hemoglobin.
Name an early Craniate.
Haikouichthys
Hagfish
Explain some characteristics of Hagfish.
Hagfish are the least derived of all craniates. They have a skull, but no jaws or backbone.
They have a small brain, eyes, and ears, along with Keratin teeth and are aesthetically pleasing creatures .They swim in a snake-like fashion by exerting force.
How do Hagfish feed?
Hagfish feed on dead or dying fish.
What is a defensive mechanism used in Hagfish?
They use slime for defense by suffocating their predators.
They are capable of producing several liters of slime per minute, which is helpful for medical surgical purposes.
Explain some key characteristics that distinguish vertebrates from invertebrates.
-- DiX transcription factors, developed nervous system and skeletal support from backbone, not just notochord.
Aquatic vertebrates acquired fins for swimming and gills for gas exchange.
Lampreys
Explain some characteristics of Lampreys.
--Some characteristics of Lampreys would include that they are marine, stream dwelling parasites who feed by clasping a round jawless mouth to a flank of fish.
It’s rasping tongue ingests the fish’s blood.
Lamprey structural anatomy included a skeleton of cartilage, (but no collagen), a protein matrix, and vertebrae-like projections from the notochord.
What were conodonts?
Conodonts – Slender early vertebrates with eyes controlled by muscle that had paired fins, an inner ear, no jaws, and a muscular pharynyx.
From where did bones derive from?
-- Bones derived from early cartilage.
How did mineralization of bones occur?
-- Mineralization happened because and when early chordates were suspension feeders, but as they became larger, they were able to ingest larger particles (no more phagocytosis) so they needed mineralization in the mouth (teeth). Also, it helped by aiding in advance trophic structure? (according to the PowerPoint.)
Gnathostomes
Describe some characteristics of Gnathostomes.
--They are jawed vertebrates whose hinged structure enables grinding; this may have been derived from skeletal rods supporting gill slits. Gnathostomes have 4 clusters of Hox genes as well as an enlarged forebrain with better smell and vision. If their life is aquatic, they have a lateral line system.
Explain how Gnathostomes started the mineralization of bones.
--Gnathostomes started the mineralization of bones, as a modification of skeletal rods that previously supported pharyngeal gill slits, which were no longer required for suspension feeding which remained as a major site for gas exchange.
What were the 2 main features in Gnathostome fossils?
- Paired fin & Jaw
- Jaw to grab pretty and take larger portions of food intake
What were two main branches of prehistoric Gnathostomes?
- Placoderms (plate skinned)
- Acanthodians (lobe finned)
Both went extinct.
Sharks & Rays
What are skeletons of chondrichthyans composed of?
-- Cartilage with calcium
Why can we conclude that mineralization occurred in Chondrichthyans?
-- Because traces of bone can be found in teeth and vertebrae.
What are the two classes of Chondrichthyans?
Sharks
Describe the way in which sharks swim.
-- Sharks have a streamlined body and are good swimmers, but they have bad maneuverability. They use various muscles for directional control, such as:
- Forward – Trunk & tail fin
- Stabilize – Dorsal fin
- Lift – Pectoral & Pelvic fins
How do sharks gain buoyancy?
-- Sharks are good swimmers who gain buoyancy from oil in their liver, but because it is denser than water if they stop swimming, they sink.
How do sharks pursue gas exchange?
--By moving water past gills (by swimming) OR by muscles in pharynx and jaws pumping water over gills (by resting)
How do sharks feed?
--Sharks feed by suspension feeding by consuming plankton or swallowing prey whole. They have loose teeth that move forward, while old teeth fall out.
Describe the digestive system of a shark.
-- Sharks have a short digestive tract and spiral valve (corkscrew-shaped ridge that increases surface area & prolongs the passage of food through the digestive tract.)
Compare and contrast the advantages and disadvantages of certain senses that sharks have.
Sharks have very acute senses. They have sharp vision, yet no color. Their nostrils are dead-end cups only used for olfactory purposes (smelling), not for breathing. Sharks also have a region in the head that can detect electric fields generated by muscle contractions of nearby animals. They do not have eardrums, but their entire body transmits sound to the whole body.
Shark eggs are fertilized ____________.
--Internally.
(Males have a pair of pelvic fins that transfer sperm to the reproductive tract)
What 3 categories do sharks fall under, in terms of egg production?
- Oviparous (lay eggs)
- Ovoviviparous (live birth nourished by egg yolk)
- Viviparous (live birth & nourished by not egg yolk, but placenta)
What is a cloaca?
It is a common chamber to the outside of the shark.
Familiarize yourself with this picture:
Describe some characteristics of Rays.
--Rays are flattened bottom dwellers whom feed using jaws to crush mollusks. They have pectoral fins to propel through water and a tail with barbs (and quite possibly venom) as a defense.
Explain the skeletal structure of Osteoichthyes.
--The name “Osteoichthyes” means bony fish. It has a bony endoskeleton with a calcium phosphate matrix.
What is gas exchange like for Osteoichthyes?
--They breathe by drawing water over four to five pairs of gills.
Water is drawn in through …the mouth à pharynx à between gills.
A movement of operculum and contraction of muscles do this.
Define the air sac swim bladder
Air Sack Swim Bladder – Controls buoyancy; movement of gases from blood to swim bladder make animal rise; transfer back to flood cause it to sink.
Evolved from lungs.
Describe the skin of Osteoichthyes.
-- It contains flattened, bony scales. The glands secrete a slimy mucus over the skin which reduces drag during swimming.
Osteoichthyes have a _______ ____ ______.
-- Lateral Line System.
Reproduction is mostly…?
-- Oviparous.
Identify the brain, liver, intestine, and gonad:
(And familiarize yourself with this picture)
Osteoichthyes are broken down into two major groups, today. What are they?
- Ray-finned fish (trout, tuna, bass…)
- Lobe-finned fish (lungfish, coelacanths…)
What are some characteristics of Ray-finned fish?
-- They have fins supported by long, flexible rays for steering and defense. Ray-fins originated in fresh water and have migrated to the ocean; some are catadromous (eels) or anadromous (salmon). They are a very diverse group.
What are some characteristics of Lobe-fins?
-- There is a presence of rod-shaped bones surrounded by muscle in pectoral and pelvic fins. They used to live in brackish wetlands & walk under water. 3 classes remain today...
- Class Actinistia (coelancanths)
- Class Dipnoi (lungfish)
- Class Tetrapod
- All found in southern hemisphere.
Questions from the Book
34.1 - Chordates
- Humans are chordates, yet they lack most of the main derived characters of chordates. Explain.
In humans, these characters are present only in the embryo. The notochord becomes disks between the vertebrae, the tail is almost completely lost, and the pharyngeal clefts develop into various adult structures.
- How do pharyngeal slits function in feeding in tunicates & lancelets?
As water passes through the slits, food particles are filtered from the water and transported to the digestive system.
34.2- Craniates
- What characteristics do hagfishes have that tunicates and lancelets lack?
Hagfishes have a head and skull made of cartilage, plus a small brain, sensory organs, and tooth-like structures. They have a neural crest, gill slits, and more extensive organ systems. In addition, hagfishes have slime glands that ward off predators and may repel competing scavengers.
34.3- Vertebrates
- How are differences in lamprey and conodont anatomy reflected in each animal’s feeding method?
Lampreys have a round, rasping mouth, which they use to attach to fish. Conodonts have two sets of mineralized dental elements, which may have been used to impale prey and cut it into small pieces.
- What key role did mineralized bone play in the first vertebrates?
Mineralized dental elements allowed vertebrates to become scavengers and predators. In armored jawless vertebrates, bone served as external defensive armor.
34.4- Gnathostomes
- What derived characters do sharks and tuna share?
Both are gnathostomes and have jaws, four clusters of Hox genes, enlarged forebrains, and lateral line systems. Sharks secondarily lost much mineralization in their skeletons, which consist mainly of cartilage, whereas tuna have bony skeletons. Sharks also have a spiral valve. Tuna have an operculum and a swim bladder, as well as flexible rays supporting their fins.
2. Contrast the habitats of the three surviving lineages of lobe-fins.
Coelacanths live in deep marine waters, lungfishes live in ponds and swamps and terrestrial vertebrates live on land.
Vertebrates II
What are some characteristics of Tetrapods?
-- Limbs that support their weight on land, feet with digits, bones of hind legs are fused to backbone, no gill slits (ears and glands instead).
Explain the Origin of Tetrapods
-- Legs and limbs emerged from fish due to logs or muddy bottoms. Lungs emerged form oxygen-poor water (EX: Acanthostega was a prehistoric aquatic being whom had had limbs.)
Who is included in class Amphibia?
-- Order Urodeles (Salamanders), Order Anura (Frogs), and Order Apoda (Caecilians)
What are some characteristics of Urodeles?
-- Salamanders & Newts can be either totally aquatic or live on land. They walk with a side to side bending of their body due to their ancestry of early terrestrial tetrapods. They display paedomorphosis (meaning they retain larval characteristics as adults)
What are some characteristics of Anura?
-- Frogs are terrestrial or aquatic, and use their powerful hind legs to hop along the terrain. They also feed by nabbing insects using a flicking motion from their long and sticky tongue.
What are some beneficial adaptations frogs have developed to avoid predators?
a.) Skin glands that secret distasteful/poisonous mucus
b.) Bright, vivid colors of their skin (considered poisonous/dangerous to predators)
c.) Camouflage with natural surroundings (if they are not bright and vivid)
Frogs mostly live in ___ environments, places with high ____.
--Damp; Humidity
How do frogs pursue gas exchange?
-- Mostly through skin or lungs
Explain the metamorphosis cycle of Class Anura.
-- The word amphibian itself means “2 lives”. The larval stage of a frog is called a tadpole, which is an aquatic herbivore with gills, a lateral line system, and a long finned tail. After metamorphosis, the tadpole develops legs, lungs, external eardrums and the digestive system of a carnivore. Gills and Lateral Line System disapear.
What are some characteristics of Order Apoda?
- Caecilians are legless and blind. They occupy tropical regions, and they superficially resemble a worm.
Explain fertilization for Amphibians.
-- Fertilization is external. The male spews out the sperm, while the female spews out the egg, which gets fertilized at contact (in water). They lay eggs in water or in a moist environment and the eggs are housed inside the mouth, on the back, or in the stomach. Amphibians can be ovoviviparous or viviparous.
How do amphibians interact during breeding season?
-- Vocal communication
Why is the amphibian population rapidly declining?
-- Habitat degradation, spread of fungal pathogen, and acid precipitation.
(Tsk, tsk, tsk. Amazing how much carbon emission due to human impact can do.)
What is the major derived characteristic of amniotes?
-- The amniotic egg, which contains the extraembryonic membrane, a specialized membrane that protect the embryo. It functions in gas exchange waste storage, and transfer of stored nutrients to the embryo. It develops from tissue layers that grow out of embryo.
(Picture from Powerpoint)
Using the picture above, identify the chorion, yolk, allantois, and amnion. Give the function of these parts.
a.) Chorion – Functions in gas exchange, for oxygen and carbon dioxide to diffuse across shell
b.) Yolk – Provides Nutrition to the Embryo
c.) Amnion – Functions as a shock absorber
d.) Allantois – Functions in Waste Storage
- The shell is made out of calcium carbonate
What are some adaptations that amniotes have developed for live on land?
-- Less permeable skin and rib cage that ventilates lungs.
Early Amniotes lived in ____ environments and were ______ with ______ teeth
-- Drier; Herbivores; Grinding
The reptile clade includes whom?
Snakes, Turtles, Birds, Lizards…
What are some characteristics of the reptilian clade?
-- Scales, internal fertilization, and ectodermicity.
What are the benefits of scales?
n They are made out of keratin, providing a waterproof barrier that helps prevent dehydration and they also prevent reptiles from breathing through their sin.
What is the difference between an ectoderm and an endoderm?
-- Ectoderms eat far less often than endoderms because they utilize external sources (such as heat from the sun) for body heat. (Because of this, they eat only as much as 10% as endoderms of the same size do). Endoderms on the other hand rely on metabolic breakdown of food for body heat.
How is the reptilian clade broken down?
One singular group (Diapsids, known for a pair of holes on either side of their skull) which is then broken down into two groups –
a.) Lepidosaurs (lizards and snakes)
b.) Archosaurs (crcodillians and dinosaurs)
Describe the lineage of Lepidosaurs.
-- There are two major species left – Tuatara and Squamates.
Tuatara – 220 million years ago; Live off coast of New Zealand and eggs were devoured by rats. They live 100 years and (according to powerpoint) their sex is determined by soil temperature and they have a 3rd eye light sensor.
[Familiarize yourself with this picture]
Squamates – They include lizards and snakes. Snakes are legless and evolved from lizards. They move by producing waves of lateral bending, which pushes the snake forward OR they move forward by gripping the ground with belly scales. Snakes are carnivorous and they have many hunting aids such as acute chemical senses, sensitivity to ground vibrations, heat detecting organs, and a venomous bite. (However, they lack eardrums.)
(Familiarize yourself with this drawing)
What are some characteristics of turtles?
-- They have a boxlike shell connected to the vertebrae, clavicles, and ribs. Turtules are adapted to desserts and ponds. They can retract their head in two ways:
Pleurocline – Folds neck in horizontally
Cryptocline – Fords neck in vertically
(Familiarize yourself with this drawing)
What are some characteristics of the crocodilian lineage?
-- They breathe air through upturned nostrils and sex is determined by temperature.
What were some uses of feathers before they adapted for flight?
--Insulation, camouflage and courtship display
What are some adaptations for flight?
-- No urinary bladder, only one ovary, small gonads, no teeth, hallow bones, feathers, and brain size changes occasionally.
How do wings work?
-- The wing shape is designed for lift and maneuverability and the formation of the wings form airfoils. Power for flapping comes from contractions of breast (pectoral) muscles and they are anchored to the sternum.
List different types of feathers.
-- Bristle, semiplumes, down, countour, filoplumes (vibration sensors).
What are some benefits of flight?
-- Though it requires a great expenditure of energy from active metabolism, flight enhances hunting and scavenging, enables the consumption of nutritious flying insects, migration is possible, as is escape from predators.
Are birds endodermic or ectodermic?
-- They are endodermic; They use their own body heat to keep an even temp. Feathers also supply insulation and tissues are well-supplied with oxygen and nutrients (supporting high metabolism) due to good circulatory (4 chambered heart) and repertory system.
What are Ratites?
-- Flightless birds
How are different birds distinguished?
-- Body profile, flying style, behavior, feather colors, and beak-shape as well as foot structure (perching, grasping, raptor, or swimming).
What are some derived characteristics of mammals?
-- Mammary gland for producing milk for offspring, hair, fat layer under skin to retain body heat, endothermic and high metabolic rate, efficient circulatory and repertory systems, diaphragm for ventilating lungs, different teeth, larger brain, and capability to learn.
Mammals had a temporal fenestra (a hole behind eye socket), where jaw muscles would pass through the hole. Previous bone used in jaw, which wound up over our inner ear.
What are the three lineages of mammals?
a.) Monotremes (egg laying mammals)
b.) Marsupials (mammals with a pouch)
c.) Eutherains (placental mammals)
What are some characteristics of monotremes?
-- Monotremes lay eggs, and have hair but no nipples. Milk is sucked by the young child through pores in the mother’s fur. They have low metabolic rate compared to other mammals.
What are some characteristics of marsupials?
-- Marsupials include kangaroos, sugar gliders, and Tasmanian devils and have a high metabolic rate as well as nipples. They have a placenta, which is a structure where nutrients diffuse into embryo from the mother’s blood. Marsupials are born early in development and finish developing in the maternal pouch. Most pouches face towards the front, but for diggers like bandicoots, they face the back to protect the newborn baby from dirt. They are found only in Aurstralia, South America, and North America.
What are some characteristics of eutherians?
-- They finish development inside the womb, longer pregnancy, similar to marsupial counterparts, and they are placental mammals.
What are some characteristics of primates?
-- Digits with flat nails, opposable thumbs, hands and feet for grasping, large brain, short jaws, excellent hand-eye coordination, and eyes that face front.
What are the three groups of primates?
a.) Lemurs
b.) Tarsiers
c.) Anthropoids
Mammalian Orders to Know (taken straight from powerpoint)
Monotremata (monotremes)
Marsupialia (marsupials)
Proboscidea (elephants)
Tubuliddentata (aardvarks)
Sirenia (manatees and dugongs)
Xenarthra (sloths, anteaters, and armadillos)
Rodenita (squirrels, mice, beavers)
Lagomorpha (rabbits, hairs, pikas)
Primates (monkeys, humans, lemurs)
Carnivora (dogs, wolves, bears, otters, cats…)
Chirpotera (bats)
Questions from the Book
1.) Was Acanthostega a terrestrial tetrapod? Explain your answer.
No. Though it had four limb-like appendages with fully formed legs, ankles, and digits, its pectoral and pelvic girdles could not carry its body on land. It had gills and a tail fin that propelled it in water.
2.) What key roles did mineralized bone play in the first vertebrates?
Some fully aquatic species are paedomorphic retaining larval features as adults. Species that live in dry environments may avoid dehydration by burrowing or living under moist leaves, and they protect their eggs with foam nests, viviparity, or other adaptations.
34.6 – Amniotes
1.) Defend or refute the following statement: The amniotic egg of a reptile is a closed system in which the embryo develops in isolation from the outside environment.
The amniotic egg is not an entirely closed system. Nutrients used by the embryo are stored within the egg (in the yolk sac and albumen) as are some metabolic wastes produced by the embryo (in the allantois). However, the embryo exchanges oxygen and carbon dioxide with the outside environment via the chorion, allantois, and eggshell.
2.) Identify four avian adaptations for flight.
Birds have weight-saving modifications, including having no teeth or urinary bladder and only one ovary in females. The wings and feathers are adaptations that facilitate flight, as are efficient respiratory and circulatory systems, which support a high metabolic rate.
1.) Contrast monotremes, marsupials, and eutherians in terms of how they bear young.
Monotremes lay eggs. Marsupials give birth to very small live young that remain attached to the mother in a pouch. Eutherians give birth to more developed live young.
2.) Identify at least five derived traits of primates.
Hands and feet adapted for grasping, flat nails, large brain, forward looking eyes on a flat face, parental care, mobile big toe and thumb.
