Week 3 and Week 4

Question 1

geographic range

Answer 1

describes where individuals of a species might be located

Question 2

cosmopolitan species

Answer 2

an extreme, worldwide in distribution

Question 3

endemic species

Answer 3

found in only a small restricted area.

Question 4

factors determining the geographic range of a species

Answer 4

history
biological tolerances
other species
or a combination of the above

Question 5

examples of physiological factors limiting distribution

Answer 5

palms- widespread through tropics and subtropics but are absent where winter temps go below freezing This is because the “hearts of palm” occur at the top of the trunk and are not tolerant of freezing
Also their seeds are water-dispersed, and can live in the ocean for months therefore coconut palms tend to occur on beaches or close to waves

Question 6

Historical factors determing range of a species (an example)

Answer 6

A “Gondwanan” distribution from the supercontinent when continents no longer touching used to touch eachother.

Question 7

populations

Answer 7

groups of individuals livingina habitatatagiventime

Question 8

the number of individuals in the population at any given time

Answer 8

size or abundance

Question 9

The number of individuals in the population per unit area or unit volume

Answer 9

density (for many organism it is the density of the population rather than it’s actual numbers that exerts a real effect on the organism)

Question 10

Clumping

Answer 10

Clumping sometimes occurs because some areas of the habitat are more suitable than others (ex- salamanders clumped under fallen logs in the forest or plants clumping because of where seeds fall)

Question 11

Random distribution

Answer 11

Uncommon

Occurs in the absence of strong attraction or repulsion among individuals

Question 12

Regular distribution

Answer 12

Generally happens because of interactions of individuals in the population (competition, territoriality, human intervention)

Question 13

Age structure

Answer 13

The number of individuals at different ages

Question 14

Sex ratio

Answer 14

The proportion of individuals of each sex ( the number of females is more important in the growth rate of populations)

Question 15

variability

Answer 15

Differences among individuals in the population

ex- sexual dimorphism, metamorphosis

Question 16

Many organisms exist as interwoven collections of subpopulations-the total is called a

Answer 16

metapopulation

Question 17

Metapopulations

Answer 17

exhibit their own dynamics, with localized extinction, and recolonization of unoccupied areas of suitable habitat, determining their dynamics. (example cliff nesting birds and fresh water fish)

Question 18

Formula for exponential growth

Answer 18

N_o*e^rt (where t is time r is the rate and N_o is the initial population size)

Question 19

Carrying capacity

Answer 19

Populations grow until one or several limiting resources become rare enough to inhibit reproduction so that the population no longer grows

Question 20

Limiting resources

Answer 20

Can include light, water, nesting sights, nutrients, prey etc

Question 21

Density-Independent factors for limiting population growth

Answer 21

Independent of population size (ex- winter temperatures affect grasshoppers)

Question 22

In the logistic growth model what is k? and what is N?

Answer 22

K is Carrying capacity

N is the number of individuals in the population at a given time

Question 23

When N>K what happens to the populations?

Answer 23

They decline

Question 24

Demography

Answer 24

The study of the age structure and growth of populations. Essentially the study of birth, reproduction, and death as it relates to populations.

Question 25

Thomas Mathus

Answer 25

A famous early demographer. Reached the conclusion that human populations tend to grow until the have outstripped their food supply. (why are there always poor people?)

Question 26

Complete enumeration

Answer 26

count every individual in the population

Question 27

R_o

Answer 27

the rater of population growth or decline per capita

Question 28

Survivorship curve

Answer 28

traces the decline of a group of newborns over time (plots the probability of surviving to a certain age)

Question 29

Survivorship curve Type I

Answer 29

A convex curve. Most individuals will live to adulthood with most mortality occuring during old age.

Question 30

Survivorship curve Type II

Answer 30

A straight line. An individuals chance of dying is separate from it’s age (ex-small birds)

Question 31

Survivorship curve Type III

Answer 31

A concave curve. few individuals live to adulthood, the chance of dying decreases with age (ex-snapping turtles and redwood trees)

Question 32

Current age structure of Africa

Answer 32

More young people than old people. Populations will increase in the future

Question 33

Life history

Answer 33

timing of an organisms life and death

Question 34

fitness

Answer 34

How many offspring an organism produces that are ultimately able to produce their own offspring.

Question 35

Semelparity

Answer 35

One large reproduction effort (example most insects and annual plants)

Question 36

Interoparity

Answer 36

Fewer offspring reproductive episodes (example perrenial plants and most large mammals)

Question 37

Clutch size

Answer 37

The number of offspring per reproductive episode