Midterm Exam

Question 1

Ecology is defined as?

Answer 1

relationships between organisms and their environment

Question 2

the difference between climate and weather is that?

Answer 2

climate is the long term pattern of weather

Question 3

Which is a greenhouse gas? carbon dioxide, oxygen, ozone, or nitrogen

Answer 3

Carbon dioxide

Question 4

Where did the Dust Bowl occur?

Answer 4

Southern Texas

Question 5

The value of photosynthetically active radiation (PAR) above which no further increase in photosynthesis occurs is referred to as?

Answer 5

The light saturation point

Question 6

Overall, water movement from the soil, through plant tissues, and finally to the atmosphere through transpiration, is driven by a gradient of?

Answer 6

water potential (osmotic pressure is also correct)

Question 7

which group of plants responds to increased CO2 with the highest biomass enhancement ratio?

Answer 7

C3 plants

Question 8

which equation reflects the exponential model of population growth?

Answer 8

N(t)=N(0) ^ert
- N(t): population size at time
- N(0): initial population size
- r: the intrinsic rate of population growth

Question 9

What is the advantage of sexual reproduction?

Answer 9

increased genetic variability

Question 10

The K in the term K-strategist refers to?

Answer 10

carrying capacity

Question 11

The form of competition in which growth and reproduction are depressed equally across individuals in a population as the intensity of competition increases is called:

Answer 11

scramble competition

Question 12

When the trunk or limb of a tree provides the substrate on which an epiphytic orchid grows, the arrangement benefits the orchid, which gets nutrients from the air and moisture from the aerial roots, while the tree is unaffected. The relationship is referred to as?

Answer 12

Commensalism

Question 13

In an area with high soil nutrient availability, mycorrhizal fungi become?

Answer 13

Parasitic because in high nutrient availability, the plant does not lean on the fungi as much but it still needs carbon from the plant

Question 14

A species of cattail inhabits both deep and shallow water in the absence of a competitor but only shallow water in the presence of it. This is an example of?

Answer 14

A realized niche.
A realized niche is the actual space an organism inhabits and the resources it can access as a result of limiting pressures from other species.

Question 15

What does the following formula represent? dN1/dt = r1N1(1-(N1+N2)/K1)

Answer 15

Population growth of species 1 in presence of species 2

Question 16

An organism that feeds on plant or algal tissues is reffered to as a(n)?

Answer 16

herbivore

Question 17

Which type of parasite is always photosynthetic?

Answer 17

hemiparasites

Question 18

Which mutualist cannot survive without the mutualistic interaction?

Answer 18

Obligate mutualist because both species are so dependant on each other that they cannot survive or reproduce without the interaction.

Question 19

What would you predict would happen to a plant after being invaded by Rhizobium bacteria?

Answer 19

It would grow better
Because the rhizobium bacteria form a mutualistic relationship with the plant, fixing atmospheric nitrogen into a usable form, improving growth.

Question 20

Which of the following has the highest species richness? A community with:
a. 36 species with very low evenness
b. 33 species of low evenness
c. 35 species of high evenness
d. 34 species of high evenness

Answer 20

a. 36 species (most species richness)

Question 21

Seasonality occurs on planet earth because of its _______ with respect to the plane it travels around the Sun.

Answer 21

Axial tilt

Question 22

The wavelengths that make up the visible light spectrum are referred to as _______ radiation?

Answer 22

Photosynthetically active radiation (PAR)

Question 23

In the temperate regions of the world, many forest tree species are ______, shedding their leaves during the winter months.

Answer 23

deciduous

Question 24

The outward appearance of an organism for a given characteristic is called its _______?

Answer 24

Phenotype

Question 25

A(n) _______ is a population that has adapted to its unique local environmental conditions

Answer 25

ecotype

Question 26

Reversible phenotypic changes in an individual organism in response to changing environmental conditions is referred to as _______?

Answer 26

acclimation

Question 27

an example of amensalism would be?

Answer 27

Eucalyptus trees and other plants: Eucalyptus trees release chemicals that inhibit the germination of other species in the vicinity (allelopathy)
Penicillium and Bacteria: Penicillium produces penicillin, which acts as an antibiotic. The secretion inhibits the growth of nearby bacteria, while the Penicillium is unaffected.

Question 28

The number of seeds produced by a plant is _____correlated with the size of the seeds.

Answer 28

inversely - plants that produce lots of seeds tend to have smaller seeds, while those producing fewer seeds tend to have larger seeds

Question 29

the progressive decline in density and increase in biomass of remaining individuals in a population is known as ______ thinning.

Answer 29

self-thinning

Question 30

A lichen consists of a(n) _______ and an alga (or in some cases, a cyanobacterium).

Answer 30

Fungi

Question 31

Ecology is the same as environmentalism (true or false)

Answer 31

False
- Ecology is a scientific discipline that studies the interactions between living organisms and their environment.
- Environmentalism is a social and political movement to protect the environment

Question 32

Solar Radiation is more direct in tropical latitudes than in temperate latitudes (true or false)

Answer 32

True - Because the suns rays strike the Earths surface at a more perpendicular angle near the equator, resulting in more intense and direct radiation.

Question 33

Disruptive selection favours individuals possessing traits near the mean value of a population (true or false). Disruptive selection leads to ______?

Answer 33

False - Disruptive selection favours individuals with extreme traits at both ends of the spectrum, rather than those near the mean, leading to more genetic variation.

Question 34

In photosynthesis, carbon dioxide enters the leaf of a plant through its open stomata (true or false)

Answer 34

True

Question 35

Parasitoidism is a form of mutualism

Answer 35

False - Parasitism kills the host and is not mutual (true or false)

Question 36

Herbivory does not affect a plant ability to survive (true or false)

Answer 36

False - herbivory reduces the plants health, growth (auxin), and reproductive success

Question 37

Most grasses tolerate grazing and actually benefit from it? (true or false)

Answer 37

True - grazing can stimulate new growth, help control competing vegetation, and recycle nutrients back into the soil

Question 38

Carnivores can have an indirect, positive effect on plants by reducing populations of herbivores

Answer 38

True - This is trophic cascade. When carnivores prey on herbivores, they help control the herbivore population, which in turn reduces the pressure on plants from being eaten.

Question 39

Holoparasites are plants that lack a chlorophyll and are thus nonphotosynthetic, relying totally on a hosts tissues for nutrition (true or false)

Answer 39

True

Question 40

Mycorrhizae are nitrogen-fixing bacteria living within the roots of certain tropical trees (true or false)

Answer 40

False - mycorrhizae are not nitrogen fixing bacteria. Instead, they are a type of fungus that forms a mutualistic relationship with the roots of plants.