EXAM 2

Question 1

What are the key abiotic factors of equatorial rainforest

Answer 1

1. Abundant Rainfall
2. High insolation
3. Warm/Hot but not extreme temperature

Question 2

What are the key biotic factors of equatorial rainforest?

Answer 2

1. Abundant Plant Growth
2. Structurally Complex 3D Biological Communities
3. Rapid Decomposition

Question 3

What are the environmental challenge in equatorial rainforest?

Answer 3

1. High Rainfall
2. Competition for Light
3. Limited Mineral Nutrient in Soil
4. High 3D Structurally Complexity

Question 4

Role of Biocrust

Answer 4

1. Stabilize Soil
2. Boosting Fertility
3. Retaining Moisture

Question 5

Why do equatorial rainforest have high biodiversity?

Answer 5

1. Complex 3D structural complexity
2. Competition - character displacement
3. Biodiversity begets biodiversity
4. Biodiversity confers ecological resiliency

Question 6

Why do some plants adapt to have thorns?

Answer 6

Thorns fend off herbivore. It takes resources, such as water, to regenerate, thus making thorn useful in the desert where water is scarce

Question 7

Why is CAM photosynthesis useful to plants in the desert?

Answer 7

Allows plant to close the stomata during the day, minimizing water loss, and open in the night, taking in CO2

Question 8

What is evolutionary moonlighting

Answer 8

One trait serves multiple ecological/physiological functions

Question 9

What are some ecological tolerator in the desert?

Answer 9

1. Xerophyte
2. Sclerophyllous leaves
3. Thorn Plants

Question 10

What are some ecological avoider in the desert?

Answer 10

Annual Plants

Question 11

What is the difference between changes in gene expression and changes in gene function?

Answer 11

Gene expression deals with when, where, and in what circumstances a gene is expressed. This involves regulation of transcription of a gene.

Gene function deals with what a gene does.This involves physical changes in the coding sequence of a gene.

Question 12

Primary Metabolites vs Secondary Metabolites

Answer 12

Primary metabolites are metabolites that every organisms produces. Secondary Metabolites are metabolites produced by organisms under conditions to help them survive

Question 13

How does fire play a role in balancing the savannah

Answer 13

It prevents excess growth of grass and trees, preventing the savannah from becoming a forest or grassland

Question 14

Why does area with precipitation alternate between north and south of equator?

Answer 14

In the summer solstice, the tropic of cancer receives the most energy from the sun, thus more energy, means more convection current and more rain. Then, in the winter solstice, the tropic of capricorn receive the most energy, making south of equator more rainy.

Question 15

What are some adaptation to the savannah?

Answer 15

1. Baobao Trunks
2. Geoxyles
3. Thorn Tree
4. Hard Leaves (sclerophyllous)

Question 16

Why is there a longer daylight length session in the summer?

Answer 16

Higher sun angle means more energy is heating that hemisphere, resulting in longer days and less in the winter

Question 17

What are the three major planetary-scale geophysical or atmospheric factors that give rise to the tundra biome?

Answer 17

1. Dominated by polar vortex all year
2. Extreme seasonal changes in day-length
3. Strong effect of angle-of-axis seasonality

Question 18

How does climate change drive competition in the artic?

Answer 18

Red fox that lives in the south must move north, thus competing for Arctic fox

Question 19

How does perma defrost affect the climate?

Answer 19

1. Increased release of greenhouse gases because the permafrost acts as a carbon sink, releasing the carbon when melted

Question 20

Ecotypic Differentiation vs Phenotypic Plasticity

Answer 20

Ecotypic diff. is when organism are genetically adapted to local environmental condition.

Phenotypic Plasticity is when an organism with the same genome has its phenotype expressed differently based on the condition it is at

Question 21

How does caribou demonstrate photoperioidc?

Answer 21

Caribou have a mechanism to optimize the measurement of daylength for their breeding cycle. By measuring the length of day length, they are able to breed after the growth of plants but before the emergence peak of mosquito

Question 22

How is climate a change a threat to the Artic in terms of fire?

Answer 22

Although warmer temperature can cause more vegetation growth, more growth means higher fire risk when lightning strikes.

Burning can create a scar, contributing to the decrease in albedo because of its dark coloring, turning the artic into an carbon dioxide source

Question 23

What is the difference between acclimation and adaptation?

Answer 23

Acclimation refers to a short term physiological, morphological, or biochemical change to an organism to increase fitness

Adaptation refers to a long term EVOLUTIONARY change that increase fitness of an organism in a new or changing environment

Question 24

How does polyp increase its calcium carbonate?

Answer 24

When polyp eat, it rises out of its skeleton. It deposit calcium carbonate into this space, thus adding the structure to the reef

Question 25

What gives polyp energy to eat?

Answer 25

Symbiotic Relationship with zooxanthellae

Zooxanthellae produces nutrients (oxygen, sugar fat) and polyp provides carbon dioxide and sheleter

Question 26

How does coral reef expand?

Answer 26

When polyp die, more poly built their exoskeleton on top of the dead one

Question 27

How does excessive nutrient affect the coral reef?

Answer 27

1. It promotes excess growth of algae, blocking sunlight for polyp to use.
2. Decaying of algae use up oxygen, depriving the level of dissolved oxygen in the water, killing aquatic organism. Excessive nutrients mean more algae means more decay, means less oxygen

Question 28

What are the conditions coral reef need to form?

Answer 28

1. Photic Platform
2. Clear Warm Water

low level of free nutrient
low turbidity
high sunlight