Ch 27: The Rise of Animal Diversity Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

_______ is an ancestral protist, which is the most recent common ancestor for Kingdom Animalia.

A

Metazoa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Eumetazoa represents the origin of tissues.

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Most animals are invertebrates.

A

Most groups on the cladogram are invertebrates.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The Cambrian Explosion

A

jj

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Before the Cambrian Explosion,

most animals were scavengers, grazers, or filter feeders.

A

*** Predator-prey interactions led to “evolutionary arms race”.
Increase in oxygen –> higher metabolism, larger size triggered diversification.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Evolution of genes that regulate development (Hox genes)

A

**

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

A third hypothesis proposes that the origin of Hox genes (see Concept 23.3) and other genetic changes affecting the regulation of developmental genes facilitated the evolution of new body forms. These hypotheses are not mutually exclusive, however; predator-prey relationships, atmospheric changes, and changes in the regulation of development may each have played a role.

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Read about Hox genes
Chapter 16, pp. 333-335
Chapter 18, pp. 380-381
Chapter 23, pp. 474-475

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The Cambrian explosion occurred in _____, and happened about ___ million years ago.

A

water

535

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

In contrast, the evidence of vertebrates on land does not appear in the fossil record until about ___ million years ago.

A

365

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Animals required fewer _____ adaptations for land than plants did.

A

novel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

All chordates share a set of derived characters, though many species possess some of these traits only during embryonic development. Figure 27.17 illustrates four key characters of chordates:

A
  1. ) a notochord
  2. ) a dorsal, hollow nerve cord
  3. ) pharyngeal slits (or pharyngeal clefts)
  4. ) a muscular, post-anal tail
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the only novel adaptation that insects had to develop in order to survive on land?

A

adaptation for gas exchange (tracheal system)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

According to Figure 27.21, what adaptations did terrestrial vertebrates have to develop in order to survive on land?

A

Support structure – already had a skeletal system, but needed limbs
Protection against dessication (amniotic egg/scales)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The recent discovery of a fossil called Tiktaalik provided new details on how this process of modification occurred (Figure 27.25). Like a fish, this species had fins, gills, and lungs, and its body was covered in scales. But unlike a fish, Tiktaalik had a full set of ribs that would have helped it breathe air and support its body.

A

*

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Also unlike a fish, Tiktaalik had a ____, allowing it to move its head about. In addition, the bones of Tiktaalik’s front fin had the same basic pattern found in all limbed animals: one bone (the humerus), followed by two bones (the radius and ulna), followed by a group of small bones that comprise the wrist.

A

neck

17
Q

Finally, Tiktaalik’s pelvis and rear fin were larger and more robust than those of a fish; the pelvis is the bony structure to which hind limbs are attached in tetrapods. Although it is unlikely that Tiktaalik could walk on land, the skeletal structure of its fins and pelvis suggests that it could prop itself up and walk in water on its fins. Since Tiktaalik predates the oldest known tetrapod, its features suggest that key “tetrapod” traits, such as a _____, ____, and a neck, were in fact ancestral to the tetrapod lineage.

A

wrist, ribs

18
Q

What important adaptations do amniotes share?

A

amniotic eggs

rib cage

19
Q

Which of the following are amniotes?

amphibians
reptiles
egg-laying mammals
fish

A

reptiles (which includes birds btw)

egg-laying mammals

20
Q

Why is the amniotic egg considered to be such an important evolutionary innovation?

A

It allowed eggs to be laid in terrestrial environments.