ecology

Question 1

What is the biosphere?

Answer 1

• The part of the Earth’s surface that supports life
• made up of biomes

Question 2

What is ecology?

Answer 2

that study of the inter-relationships between organisms and their environment.

Question 3

What are biotic factors?

Answer 3

• Living factors that affect an ecosystem
• predation, parasitism and competition.

Question 4

What are abiotic factors?

Answer 4

• Non-living factors that affect an ecosystem.
• rainfall, soil ph, temperature, light, soil conditions

Question 5

What is an ecosystem?

Answer 5

• a definable area with its community of organisms and physical environment, all interacting as a relatively self-sustaining unit.
• Ecosystems are dynamic.

Question 6

What is a population?

Answer 6

-all of the interbreeding organisms of the same species living in one particular habitat at the same time.

Question 7

What is a community?

Answer 7

• all the populations of all of the species living and interacting in a particular ecosystem at the same time.

Question 8

What is a niche?

Answer 8

• The functional role an organism takes in an ecosystem
• Two species cannot occupy the same niche

Question 9

Why is the human population growing very fast?

Answer 9

• better farming techniques
• better standards of living
• medical care
• immunisation programns
• better housing.

Question 10

What are the main factors in measuring the world population?

Answer 10

• birth rate vs death rate

Question 11

Why is the death rate in the UK decreasing and why is there a higher life expectancy?

Answer 11

• Better standards of living
• medical care
• immunisation programs
• medical discoveries
• improved sanitation.

Question 12

What is happening to the birth rate in the UK?

Answer 12

• not increasing
  -improved methods of contraception
• high cost of child rearing
• changing religious beliefs.

Question 13

How do you work out population change?

Answer 13

• pop growth = birth rate + immigration - deaths and emigration
• Percentage pop growth = pop change during the period/ pop at the start of the period.

Question 14

What problems arise from an exponentially growing population?

Answer 14

• increasing demand on the environment
• raw materials are being used up and we use more energy in manufacturing items for our lifestyle
• Producing more waste causes pollution in water, lan,d and air
• less land for plants and animals

Question 15

How do you calculate death rate?

Answer 15

dr = number of deaths per year / total population In the same year x1000

Question 16

What factors affect the death rate?

Answer 16

• life expectancy
• food supply
• medical care
• war
• natural disasters

Question 18

How do you calculate the birth rate?

Answer 18

• br = number of births per year / total population in the same year x 1000

Question 19

What is demographic transition?

Answer 19

• birth rates are low, and life expectancy is high
• This leads to a levelling off of the population

Question 20

What is competition?

Answer 20

The struggle for resources between individuals

Question 21

What is interspecific competition?

Answer 21

• competition between members of different species

Question 22

What is intraspecific competition?

Answer 22

• competition between members of the same species.

Question 23

What three resources do animals compete for?

Answer 23

• food
• mates
• territory

Question 24

What four resources do plants compete for?

Answer 24

• water
• nutrients
• space
• light