2. Ecology Pt4

Question 1

Why do organisms have adaptations?

Answer 1

It enables them to survive in the conditions they normally live in

Question 2

Define habitat?

Answer 2

Where an organism lives

Question 3

Define population

Answer 3

All the organisms if 1 species living in a habitat

Question 4

Define community

Answer 4

The populations of different species living in a habitat

Question 5

Define ecosystem?

Answer 5

The interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of the environment

Question 6

Define interdependence?

Answer 6

• Where in a community each species depends on other species for things such as food, shelter, pollination & seed dispersal
• if one species is removed it can affect the whole community

Question 7

What’s a stable community?

Answer 7

It’s where all the species & environment factors are in balance so that population sizes remain fairly constant

Question 8

To ………….. and ………… organisms require a supply of …………… from their surroundings and from the other living ………….. there

Answer 8

Survive
Reproduce
Materials
Organisms

Question 9

List 7 abiotic factors which can affect a community?

Answer 9

1. Light intensity
2. Temperature
3. Moisture levels
4. Soil pH & mineral content
5. Wind intensity & direction
6. Carbon dioxide levels for plants
7. Oxygen levels for aquatic animals

Question 10

What are 4 biotic factors that can affect a community?

Answer 10

1. Availability of food
2. New predators arriving
3. New pathogens
4. One species outcompeting another so the numbers are no longer sufficient to breed

Question 11

What eats a producer?

Answer 11

Producers are eaten by primary consumers, which in turn may be eaten by secondary consumers & then tertiary

Question 12

Why are producers so important?

Answer 12

Because photosynthetic organisms are the producers of biomass for life on earth

Question 13

How can you find the distribution and abundance of a species?

Answer 13

Transect

Quadrat

Question 14

What do consumers do?

Answer 14

• ones that kill & eat other animals are predators
• those that are eaten are prey
• in a stable community the number of predators and prey rise and fall in cycles

Question 15

What do producers do?

Answer 15

• Food chains begin with a producer which synthesises molecules
• usually a green plant or alga which makes glucose by photosynthesis
• they transfer about 1% of the incident energy from light For photosynthesis

Question 16

How do decomposers work?

Answer 16

• They break down dead plant & animal matter by secreting enzymes into the environment into small soluble food molecules
• Which then diffuse into the microorganisms

Question 17

What’s found in trophic level 1?

Answer 17

Plans & algae make their own food & are called producers

Question 18

What’s found in trophic level 2?

Answer 18

Herbivores eat plants/algae & are called primary consumers

Question 19

What’s found in trophic level 3?

Answer 19

Carnivores that eat herbivores are called secondary consumers

Question 20

What’s found in trophic level 4?

Answer 20

Carnivores that each other carnivores are called tertiary consumers
Apex predators are carnivores with no predators

Question 21

Why are they’re usually only 4 or 5 trophic levels?

Answer 21

Because by them too much energy has been lost from the food chain

Question 22

Define biodiversity?

Answer 22

The variety of all the different species of organism on earth or within an ecosystem

Question 23

What changes can effect the distribution of animals in an ecosystem?

Answer 23

(Environmental changes)
-temperature
-availability of water
-composition of atmospheric gases 
(These changes can be seasonal, geographic or caused by human interaction)

Question 24

What’s food security?

Answer 24

Having enough food to feed a population

Question 25

What’s been introduced to control fish stocks?

Answer 25

Controlling net size and the introduction of fishing quotas

Sustainable fisheries

Question 26

Why have control over net sizes & fishing quotas been introduced?

Answer 26

• fish stocks in the sea are declining
• it’s important to maintain fishing stocks at a level where breeding continues or certain species may disappear altogether in some places