Factors Affecting Abundance And Distribution

Question 1

What is an ecosystem

Answer 1

All the organisms living in a particular area and all the non-living(abiotic) factors

Question 2

What is a habitat

Answer 2

The place where an organism lives

Question 3

What is a population

Answer 3

All of the organisms of one species in a habitat

Question 4

What is population size

Answer 4

The number of individuals of one species in a particular area

Question 5

What is a community

Answer 5

All of the organisms of different species that live in the same habitat and interact with each other

Question 6

What are abiotic factors

Answer 6

The non-living features of the ecosystem

Question 7

What are biotic factors

Answer 7

The living features of an ecosystem

Question 8

What is abundance

Answer 8

The number of individuals of one species in a particular area-dependent on abiotic and biotic factors

Question 9

What is distribution

Answer 9

Where a species is within a particular area

Question 10

Examples of factors that affect abundance of species

Answer 10

Sunlight, space, water availability, carbon dioxide and oxygen, temperature

Question 11

How does abundance vary because of abiotic factors and example

Answer 11

-factors need to be ideal for a species for organisms to grow fast and reproduce successfully
-eg when temp of a mammals surroundings are ideal for metabolic reactions they don’t have to use up as much energy maintaining their body temp meaning more energy for growth and reproduction so population size increases, if temp not ideal will have to use a lot of energy to maintain right body temp, less energy for growth and reproduction and population size decreases

Question 12

Three ways abundance varies due to biotic factors

Answer 12

-Interspecific competition
-intraspecific competition
-predation

Question 13

What is interspecific competition

Answer 13

Competition between different species for the same resources, means both populations will be smaller than if only one species there as less energy for growth and reproduction

Question 14

What is intraspecific competition

Answer 14

-competition between organisms of the same species for the same resources
-population increases when resources plentiful meaning more organisms competing for same amount of resources, eventually resources limiting and population begins to decline, smaller population means less competition which is better for growth and reproduction so pop starts to grow again

Question 15

What is carrying capacity

Answer 15

The maximum stable population size of a species that a habitat can support

Question 16

What is predation and How does predation affect abundance

Answer 16

When an organism kills and eats another organism-predator and prey populations are interlinked as if population of one changes it causes the population of the other to change
-as prey pop increases there’s more food for predators so their pop increases, as predator pop increases more prey is eaten so prey population begins to fall meaning less food for predators so their pop decreases and this repeats

Question 17

Why does distribution vary because of abiotic factors and examples

Answer 17

-organisms can only exist where the abiotic factors they can survive in exist
-eg some plants don’t grow near shoreline as soil too salty/large trees can’t grow in polar regions as temp too low

Question 18

How do biotic factors affect distribution

Answer 18

-interspecific competition can affect distribution of species eg if two species competing but one is better adapted to its surroundings, less well adapted species is likely to be out competed and it won’t be able to exist alongside the better adapted species

Question 19

What is a niche

Answer 19

The role of a species within its habitat, includes its biotic and abiotic interactions, each species has its own unique niche which can only be occupied by one species

Question 20

How can abundance be explained by the niche concept

Answer 20

Two species occupying similar niches will compete so fewer individuals of both species able to survive in the area

Question 21

How can distribution be explained by the niche concept

Answer 21

Organisms can only exist in habitats where all the conditions that make up their role exist