Test 3 Flashcards
(90 cards)
In insect and animal development what does Hox genes play a role in?
It determines morphology. It determines what limbs go where and how many of them there are
What do animals have in common?
Hox genes.
What’s the significance of flagellated protists?
They are the closest living relatives of animals.
What is the significance of the Cambrian period in today’s animals?
Increased O2, Predator-prey relationships, development of locomotion that allowed
animals to move on to land, more complex hox gene evolution, duplication
development of biomineral (chitin) exoskeletons to creat hard bodies.
What would you not expect to find in the ediacaran period?
You wouldn’t find hard bodied animals. There were only soft bodied animals during that
period, no hard parts, no exoskeletons.
In the Cambrian radiation, what genetic process was most helpful?
Gene duplication. This allowed organisms to become more complex.
How would an organism with radial symmetry move?
a. It would drift on currents.
b. Organisms with bilateral symmetry move front to back or side to side.
Know the characteristics of a sponge (Porifera).
a. No true tissues (muslces, nerves, or organs), assymetrical, sessile (doesn’t move), has
choanocytes (generate a current through their body to filter feed), they are neither
triploblastic nor diploblastic – they are a basil animal. (so they only have 1 germ layer),
Know what groups contain diploblastic organisms (have only 2 germ layers).
a. Cnidarians (jellies and corals) – they also have radial symmetry.
What groups contain deuterostomes?
Ectoprocta, Brachiopoda, Echinodermata (star fish), Chordata (All vertebrates)
When does the blastopore first appear?
a. Gastrolation
Know the characteristics of protostomes.
a. Protostomes – Devleop mouth first, determinate growth, spiral cleavage, formed from the mesoderm.
b. Dueterstomes – Develops anus first, indeterminate growth, radial growth.
Know the characteristics of ecdysozoans.
They all have a hard exoskeleton and shed it through a process called ecdysis (molting).
What group does echinoderms and chordates belong to?
Dueterostomes.
What where the factors that influenced the Cambrian explosion? (similar to question 4)
a. Increased O2, Predator-prey relationships, development of locomotion that allowed
animals to move on to land, more complex hox gene evolution, duplication of genes, and
development of biomineral (chitin) exoskeletons to create hard bodies.
What do sponges (Porifera) lack that other animal phyla have? (similar to question 8)
a. True Tissues (muslces, nerves, or organs) and symmetry.
What are choanocytes?
Cells that help the feeding process of sponges by generating a current through the sponges body so that it can filter feed.
What are amoebocytes?
a. They help in digestion and manufacture skeleton fibers (spicules) that provide structural material of sponges.
What are cribrostatin?
They create Antibiotics.
Know the Characteristics of Cnideria.
Cnideria are jellyfish. They have true tissues, they have both a non-motile (sessile) and motile form. The polyp form is like seas anemones, they don’t move around. The medusa form is like the free floating jellyfish that drift around in the water current. They are diploblastic (2 primary tissues), they have radial symmetry, hthey have a sack with digestive and vascular components, they are carnivores, they have cnidocytes (capture and hold food), and they have stinging capsules (pneumatocytes).
Know the Characteristics of Cnideria again.
Just know all of the characteristics from question 20. He will probably ask something like “which of the following is not a characteristic of jellyfish?” in both of these questions.
What members of Cnideria only occur as polyps?
Anthozoas (sea anemonies and corals).
What are scyphozoan?
A typical jellyfish. Scyphozoan is a class of cnideria often considered to be “the true Jellyfish”. They the animal that most people think of when they talk about “jellyfish”.
Which flatworm is not a parasite?
Turbellaria