CCA Semester 2

Question 1

Point Mutation (number)

Answer 1

1

Question 2

Point Mutation (definition)

Answer 2

single gene mutation, possibly resulting in an altered phenotype

Question 3

Point Mutation (example)

Answer 3

Saguaro - The uncommon “crested” appearance isn’t passed on, and only occurs on one arm of the cactus. This insinuates that it isn’t inherited, and it was discovered that it is likely a somatic (body) cell mutation in one or more genes that control the pattern of cell divison.

Question 4

Gene Duplication (number)

Answer 4

2

Question 5

Gene Duplication (definition)

Answer 5

the process of creating new DNA through cell division, possibly resulting in errors

Question 6

Gene Duplication (example)

Answer 6

Creosotebush - The incredible drought resistance found in Creosotebush is thought to be a result of whole-genome duplication events. This means that Creosotebush has been able to generate mutations much faster while still maintaining the old traits.

Question 7

Gene Transfer (number)

Answer 7

3

Question 8

Gene Transfer (definition)

Answer 8

the unpredictable transfer of genetic information between parent and offspring, resulting in differences between generations

Question 9

Gene Transfer (example)

Answer 9

Jojoba - Jojoba plants are dioecious, meaning that they have distinct male and female plants. The pollen from the male flowers is carried by wind to pollinate the seeds of the female flower. The leaves are tilted in such a way that when wind flows through them, it creates a vortex that picks up the pollen. This is also an example of co-option.

Question 10

Phenotype (number)

Answer 10

4

Question 11

Phenotype (definition)

Answer 11

the physical characteristics of an organism, as a result of how environment and genotype interact

Question 12

Phenotype (example)

Answer 12

Palo Verde - Parkinsonia microphylla has evolved small leaves that allow for less evaporative water loss. Because of the small size, they can generate leaves quickly with lots of water and can shed them quickly when that water is gone. Because of their green stems, they can continue to photosynthesize even when they have no leaves.

Question 13

Niche Occupation (number)

Answer 13

5

Question 14

Niche Occupation (definition)

Answer 14

the process of occupying a niche (an organisms relationship with living and non-living things in it’s environment) to prevent competition

Question 15

Niche Occupation (example)

Answer 15

Desert Ironwood - Desert Ironwoods are important nurse plants. Their low branches, wide canopies, and tall stature provide shade and protection for many plants and animals. Many birds nest in their branches, and certain plants (particularly succulent cacti) utilize the tree as a nurse plant and some only grow underneath Ironwoods.

Question 16

Most Available Solution (number)

Answer 16

6

Question 17

Most Available Solution (definition)

Answer 17

a species evolves the trait that is not necessarily the best response to an evolutionary problem, but what is most available in its genome

Question 18

Most Available Solution (example)

Answer 18

Devil’s Claw - Devil’s Claw has an herbaceous stem, which is uncommon in the desert, and they cover it in a sticky mucilage to prevent evaporative water loss. They also have large, tuberous roots that can store water and nutrients. This allows for the main body of the plant to ‘die’ when conditions worsen, and then revive once they improve.

Question 19

Costs & Benefits (number)

Answer 19

7

Question 20

Costs & Benefits (definition)

Answer 20

whether a trait is selected for depending on the benefits or costs

Question 21

Costs & Benefits (example)

Answer 21

Brittlebush - Brittlebush leaks a germination-inhibiting chemical when it rains that prevents nearby competitors. However, this also results in the inability to rely on nurse plants and thus brittlebush has evolved to handle extreme heat. It also can’t handle frost as a result.

Question 22

Co-Option (number)

Answer 22

8

Question 23

Co-Option (definition)

Answer 23

an existing trait evolves a new function

Question 24

Co-Option (example)

Answer 24

Jointfir - Similarly to cacti, Jointfirs take their older stems and make them woodier, so they take on more of a support function while their newer stems continue to photosynthesize.

Question 25

Coevolution (number)

Answer 25

9

Question 26

Coevolution (definition)

Answer 26

a species evolves new traits in response to the evolution of another species in its environment

Question 27

Coevolution (example)

Answer 27

Ocotillo - Ocotillo’s have the only hummingbird-friendly flowers that bloom abundantly during the spring migration, regardless of the water availability that year. The flowers are pollinated by the hummingbirds, and thus their color and shape along with the time they flower is perfect for hummingbirds.