Intraspecific interactions

Question 1

Interactions among conspecifics (same species)

Reproduction
2 points

Answer 1

1. Reproductive strategies

2. Sexual competition

Question 2

Interactions among conspecifics

Cooperation

Answer 2

kin groups & herds

Question 3

Interactions among conspecifics

Competition
5 points

Answer 3

1. Exploitation
2. Interference
3. Density
4. Carrying capacity
5. r or K selected

Question 4

5 biotic interactions

Answer 4

1. Competition
2. Commensalism
3. Mutualism
4. Predation
5. Succession

Question 5

Reproduction

Evolution

4 points

Answer 5

1. Fitness = survival and reproduction
2. Selection acts on individual phenotypes
3. Individual phenotypes maximise their fitness
4. Phenotypes with the highest fitness pass on the most genotypes

Question 6

Reproduction

Asexual reproduction

2 points

Answer 6

1. Offspring genetically identical to 1 parent - clones

2. Genetic differences arise through mutation

Question 7

Reproduction

Sexual reproduction

3 points

Answer 7

1. Gonochoric / dioecious – sexes separate
2. Hermaphrodite – individuals produce male and female gametes (simultaneous or sequential)
3. Hermaphrodite self-fertilisation

Question 8

Reproduction

Finding a mate

6 points

Answer 8

1. Behaviour - sound, colour, visual displays, gifts
2. Chemistry
3. Sexual selection
4. Sexual competition
5. Mate guarding
6. Sperm competition

Question 9

Reproduction

Sexual competition e.g. damselfly

Answer 9

Penis of male damselfly’s secondary genitalia has spines on it

used to scrape sperm of rival male out of female’s reproductive tract

Question 10

Reproduction

sexual competition e.g. heliconius butterflys

6 points

Answer 10

1. Pupal mating in Heliconius butterflies
2. Pre-copulatory mate guarding
3. Males search for female pupae on host plant
4. Compete for possession of a pupa
5. Make a hole in the cuticle of the pupa
6. Mate with female as she ecloses (emerges)

Question 11

Reproduction

population density

2 points

Answer 11

1. If population density is low may not find a mate

2. If population density is high there is an increased chance of competition

Question 12

Cooperation

usually as

Answer 12

mates rearing young

Question 13

Cooperation
sometimes as groups
2 points

Answer 13

1. kin groups e.g. lions / meercats / social insects (termites / bees, wasps, ants)
2. Herds or colonies

Question 14

Cooperation

a trade off

Answer 14

benefits of cooperation out weigh disadvantages of infraspecific competition

Question 15

Competition

3 points

Answer 15

1. Individuals live in populations
2. Individuals of the same species have very similar requirements for survival, growth and reproduction
3. If demand exceeds supply they compete for resources

Question 16

Competition
example grasshoppers
7 points

Answer 16

1. Population of grasshoppers in a field
2. For survival, growth and reproduction they must feed
3. To find food they must move, which uses energy and risks predation
4. If grass has been eaten they must move more
5. The more grasshoppers the more this will happen
6. Results in
   Increased mortality (lower survival)
   Slower development
   Reduced reproduction
7. The more grasshoppers the smaller contribution to the next generation

Question 17

Competition

Exploitation competition

Answer 17

Organisms utilise limited common resources

Question 18

Competition

Interference competition

Answer 18

Organisms exploiting a resource harm one another in the process - physically interfere with foraging, reproduction, settlement, survival

Question 19

Competition
Exploitation
4 points

Answer 19

1. Usually individuals do not interact directly
2. They respond to the level of a resource:
   Plants compete for water, light, nutrients
   Animals compete for food
3. Resource depletion zones overlap
4. Exploitation only if the resource is limited

Question 20

Competition
Resource depletion zone
2 points

Answer 20

1. Competition between plant roots (even of a single plant) where RDZs overlap
2. Plants with different shapes of root system tolerate different levels of soil mineral resources

Question 21

Competition

Resource depletion zone (resource mobile)

Answer 21

Where resource is mobile, e.g. nitrate in soils,

RDZ is wide
Overlap of RDZs

Question 22

Competition

Resource depletion zone (resource not mobile)

Answer 22

Where resource is not mobile, e.g. phosphorous (bound on soil colloids)

RDZ is narrow
No overlap of RDZs

Question 23

Competition
Interferences
4 points

Answer 23

1. Individuals may interact directly
2. One individual physically prevents another from exploiting a resource

Competition for space (territories)

Competition for mates

3. Resource depletion zones overlap
4. Interference may occur even if the resource is plentiful

Question 24

Competition

Territoriality

Answer 24

1. results from interference competition
2. Individuals without a territory make little or no contribution to future generations

3, Territoriality is linked to population regulation

4. Example: oystercatchers

Question 25

Density dependent competition e.g.

Answer 25

Flour beetle | Tribolium confusum

Question 26

Competition Density dependent competition graph y no. surviving x initial egg no.

Answer 26

``` 1. straight line increase Mortality constant Numbers dying and surviving both rise Proportion dying stays the same No competition ``` ``` 2. straight line becomes curve Mortality rate increased Numbers dying increases more rapidly Numbers surviving increases more slowly Some competition Density dependent mortality Undercompensates ``` ``` 3. straight line decrease Mortality rate increased Intense competition Density dependent mortality Overcompensates ```

Question 27

Carrying capacity K

Answer 27

When birth rate = death rate the population is at the carrying capacity (K) the maximum number of individuals the environment can support

Question 28

Population growth Intraspecific competition leads to ________ population growth curves (no of individuals against time)

Answer 28

sigmoidal (logistic) however many other factors may mask this pattern

Question 29

Life history | r selected species reproduce rapidly

Answer 29

Have a high r value

Question 30

Life history | K selected species reproduce more slowly

Answer 30

Populations close to the carrying capacity (K) of the habitat

Question 31

Life history r selected species 5 points

Answer 31

1. Characteristic of habitats that are ephemeral or unpredictable 2. Show intermittent, rapid population growth, free from intraspecific competition 3. Have variable and unpredictable mortality rates 4. Have smaller size, early maturity and 5. reproduction with smaller, numerous offspring

Question 32

Life history K selected species 3 points

Answer 32

1. Characteristic of habitats that are constant or predictable 2. Have crowded populations with intraspecific competition 3. Have larger size, delayed reproduction with larger, fewer offspring

Question 33

Life history Metamorphosis 3 points

Answer 33

1. avoids intraspecific competition 2. Resource partitioning between larvae and adults e.g. different feeding strategies within a species 3. Many species have ontogenetic (developmental) shifts in habitat, mobility, resource use, diet and trophic position

Question 34

intraspecific competition rarely results in

Answer 34

death | not evolutionary stable strategy