The reproductive barrier that separates jellyfish species that live in different ocean depths is habitat isolation. Most variability within populations comes from mutations. The type of selection seen in medium-sized starfish on a coral reef being best able to find food and avoid predators is stabilizing selection. Charles Darwin made important observations about creatures like marine iguanas and giant tortoises on the Galapagos Islands.

1. Which type of reproductive barrier separates a pair of jellyfish species
1.
Which type of reproductive barrier separates a pair of jellyfish species that could interbreed
except that one lives near the surface of the ocean and the other lives in the very deep sea?
hybrid inviability
gametic isolation
temporal isolation
behavioral isolation
habitat isolation
2.
What is the source of most variability found within populations?
mutations
gene flow
mitosis
organisms need traits so they get them
natural selection
3.
On a coral reef, it is difficult for very large knobby starfish to find enough food while very
small knobby starfish have few defenses and are gobbled up by predators very quickly. As a
consequence, the majority of the knobby starfish on this reef are medium-sized. This is an
example of which type of selection?
stabilizing selection
frequency dependent selection
directional selection
disruptive selection
sexual selection
4.
It is believed that humans are currently causing the 6th mass extinction.
True
False
5.
A large population of finches lives in a forest. The majority of these finches have red
feathers on their chest and belly but there are a few with yellow feathers and a few with
blue feathers. A huge wildfire sweeps through the forest so quickly that most of the birds

2. cannot escape. Once the fire is gone, only a few finches remain and all of them have yellow
feathers except one lone finch that has red feathers. This is an example of:
the founder effect
gene flow
natural selection
sexual selection
the bottleneck effect
6.
In the evolutionary tree below, which letter represents the most recent common ancestor of
giraffes and birds?
Evolutionary_Tree.jpg
Giraffes and birds are not related - that's crazy talk
C
B
D
A
7.
Structures, like the appendix in humans, that have little or no current importance to the
organism yet are homologous to functional organs in another organism are called:
vestigial structures
comparative structures
embryological structures
biological structures
analogous structures
8.
The shift in fur color within populations of rock pocket mice that live on hardened lava
flows is an example of:
sexual selection
frequency-dependent selection
stabilizing selection
disruptive selection
directional selection
9.
Where did Charles Darwin make some of his most important observations (about creatures
like the marine iguana and giant tortoise)?
Andes Mountains
Great Britain
Galapagos Islands
Cuba
Costa Rica
10.
Comparative embryology has shown us that which of the following are traits that humans,
mice, chickens, bats, alligators, and all other chordates share as embryos but not necessarily

3. as adults?
a tail and gills
webbed feet and feathers
a backbone and an umbilical cord
scales and gills
fu and a tail