Lab Midterm Exam

Question 1

Define ecology

Answer 1

the branch of biology that deals with the relations of organisms to one another and their physical surroundings

Question 2

What are four methods of effective scientific communication?

Answer 2

Having a take-home message
Connecting with your audience
Making numbers more accessible via metaphors and graphics
Telling a story

Question 3

What is the difference between a null and alternative hypothesis?

Answer 3

null - no change
adjacent - difference in populations

Question 4

What is an example of a descriptive statistic that measures shape?

Answer 4

mean, median, or mode

Question 5

What is an example of a descriptive statistic that measures spread?

Answer 5

standard deviation, variance

Question 6

Why are descriptive statistics that measure shape and spread important?

Answer 6

both show info of the entire populations

Question 7

What is a p-value?

Answer 7

probability for a given statistical model that, when the null hypothesis is true, the statistical summary would be equal to or more than the actual observed results

Question 8

How is a p-value used in hypothesis testing?

Answer 8

Used to determine whether or not the null hypothesis is rejected or failed to be rejected

Question 9

Define evolution as a scientist.

Answer 9

the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the hiwstory of the earth - difference in freq of alleles over time

Question 10

Define evolution as a non-scientist

Answer 10

gradual development of something, especially from a simple to a more complex form

Question 11

What are six mechanisms of evolutionary change

Answer 11

genetic drift, bottleneck effect, founders effect, natural selection, mutation, and migration

Question 12

Describe genetic drift

Answer 12

flow of genes in and out of a population due to chance

Question 13

Describe a bottleneck effect

Answer 13

a natural disaster occurs and the variety of genes in a population becomes very narrow

Question 14

Describe the founders effect

Answer 14

organisms move to establish their own population with their own genes

Question 15

Describe natural selection

Answer 15

survival of the fittests

Question 16

Describe mutation

Answer 16

occurs due to changes in DNA

Question 17

Describe migration

Answer 17

organisms coming in and out of populations

Question 18

Explain the connection between evolution and climate change.

Answer 18

· Climate change can have an affect on phenology of vegetation
· Climate change can shift a population into different geographical areas
· There is a shift in the type of organisms found in certain locations
o Dispersal based on adaption

Question 19

According to Wilson (1991) what is the primary cause of death in the gopher tortoises she studies?

Answer 19

· The cause of death for the gopher tortoises was found to be by predation

Question 20

Is the cause of death of the tortoises due to density-independent or density-dependent factors? Explain the difference between those two factors.

Answer 20

· Density-dependent
· It is density-dependent because it is not caused by a random disaster such as fire, tornado, etc. in that case it would be density-independent.

Question 21

Describe density dependent factors

Answer 21

competition for resources (food, water, light)
predation
diseases and parasites
waste accumulation

Question 22

Describe density independent factors

Answer 22

natural disasters

Question 23

What is carrying capacity and why is it important?

Answer 23

· Carrying capacity is the limit at which a population in time has reached their limit of vital resources to help maintain a healthy steady growing population
· The maximum amount of individuals an environment can sustain

Question 24

Species differ in the time it takes them to reach sexual maturity and produce their first
offspring. What are the advantages and disadvantages of reproducing early versus late?

Answer 24

early reproduction ( r selection)
- “Quantity over quality”
- High reproductive rate
- Many offspring do not
survive to adulthood
- Generally small in size
- Small parental
investment in offspring

late reproduction (k selection)
*“Quality over quantity”
* Low reproductive rate
* Most offspring will
survive to adulthood
*Generally large in size
* Large parental
investment in offspring

Question 25

Draw the three possible types of life history strategies and label them with example
species that exhibit each type

Answer 25

1. Organisms can’t afford to have many well-cared for
   offspring
2. There’s a trade-off between having many, poorly
   cared for offspring or having few, well-cared for
   offspring
3. Different species use different strategies
   T1: low infant and juvenile mortality rates, most die elderly (humans)
   T11: All ages have same mortality rates (birds)
   TIII: juvenile mortality rate is highest and lowest is adult (plants)

Question 26

What does a net reproductive rate (R0) value of 0.85 mean? What about 1.00? Or 1.45?

Answer 26

• R0 value of 0.85 means that the population is shrinking
• R0 value of 1.00 means that the population is stable
• R0 value of 1.45 means that the population is growing

Question 27

What do Franks et al. (2007) predict will happen to flowering time in the drought versus
non-drought populations of field mustard plants? What evolutionary mechanism is
creating differences among the populations?

Answer 27

Franks et al. (2007) predicts that drought populations will flower earlier.

The evolutionary mechanism is natural selection.

Question 28

Density dependent is to __ as density independent is due to __

Answer 28

biotic
abiotic