Life History

Question 1

Life cycles

Answer 1

(1) Gametic (2) Zygotic (3) Sporic

Question 2

Gametic life cycle

Answer 2

Diploid individual, zygote Haploid gametes

Question 3

Sporic life cycle

Answer 3

Diploid individual, zygote Haploid spores, gametophytes, gametes

Question 4

Zygotic life cycle

Answer 4

Diploid zygote Haploid cells, individual

Question 5

Which life cycle(s) have diploid individuals?

Answer 5

Gametic, sporic

Question 6

Which life cycle(s) have haploid individuals?

Answer 6

Zygotic

Question 7

Asexual reproduction

Answer 7

Clonal replication of individual

Question 8

Sexual reproduction

Answer 8

Offspring reproduced from a combination of parents’ genetic material

Question 9

To meet the goal of survival and reproduction, which life history makes more practical sense? Asexual or sexual reproduction?

Answer 9

Asexual. Requires less energy for sexual reproduction.

Question 10

Life history

Answer 10

How an organism grows and produces offspring. A schedule of its life.

Question 11

Principle of allocation

Answer 11

Organisms are limited in access to energy and resources and therefore must make trade-offs

Question 12

What are measures of growth/ age structure?

Answer 12

(1) Demography (2) Life tables (3) Age distribution

Question 13

Demography

Answer 13

Growth rate (r) = birth rate - death rate r = b - d

Question 14

Life table

Answer 14

summarizes age-specific population demographic data (1) Dynamic/cohort (2) Static

Question 15

Dynamic/cohort life table

Answer 15

Follows the lifetime of a cohort of individuals born at the same time

Question 16

Static life table

Answer 16

Collect info for one point in time and use as representative data. The age of DEATH is recorded for a large number of individuals born at different times.

Question 17

Age distribution

Answer 17

looks at the proportion of individuals in progressively older age classes to estimate survival, given that differences in the # of individuals from one age to the next is due only to mortality

Question 18

If we started with 100 individuals, and at age 20 there were only 75 still alive, what is the survivorship (lx) for age class 20-30?

Answer 18

0.75

Question 19

What is survivorship?

Answer 19

Survivorship (Ix) = #individuals alive at the start of an age class (Nx) / initial cohort size (N0)

Question 20

What are the types of survivorship curves?

Answer 20

(1) Type I: die old (2) Type II: constant rate of survival/death (3) Type III: die young

Question 21

Answer 21

Type I Survivorship

Question 22

Answer 22

Type II Survivorship

Question 23

Answer 23

Type III Survivorship

Question 24

R Selection

Answer 24

• Species influenced greatly by per capita rate of increase (r)
• Rapid development, early reproduction, small body size, and many, small offspring.
• Type III Survivorship
• Unpredictable environments.
• Semelparity

Question 25

K selection

Answer 25

* Controlling resources and competition with a population near its carrying capacity (K). * Slow development, delayed reproduction, large body size, and few, large offspring. * Type I & II Survivorship * Stable environments. * Iteroparity

Question 26

Semelparity

Answer 26

has single reproductive episode before death

Question 27

Iteroparity

Answer 27

has multiple reproductive cycles over the course of its lifetime.

Question 28

What are the main environmental variables that dictate life histories in plants?

Answer 28

1. Disturbance–mechanism that destroys plant biomass 2. Stress–external constraints that limit productivity/growth

Question 29

What kind of plants live under the following conditions: 1. Disturbance = High, Stress = Low 2. Disturbance = Low, Stress = High 3. Disturbance = Low, Stress = Low

Answer 29

1. Ruderals 2. Stress Tolerant 3. Competitive

Question 30

Ruderal plants

Answer 30

* Grow quickly * Reproduce rapidly * Large numbers of seeds

Question 31

Stress tolerant plants

Answer 31

* Grow slowly * Conserve resources for periodic reproduction * Low competition

Question 32

Competitive plants

Answer 32

* Grow quickly * Compete for resources * Maximize competitive advantage * later maturity * large size * larger offspring