Populations In Ecosystems

Question 1

Equation for population growth

Answer 1

Pop growth= (births + immigration ) - ( deaths + emigration

Question 2

Percentage Population growth rate equation

Answer 2

% pop growth rate = population change during the period/ population at the start of the period x100

Question 3

Mark release recapture equation

Answer 3

Estimated population size= total number of individuals in the 1st sample x total number of individuals in the 2nd sample / number of marked individuals recaptured

Question 4

Assumptions of mark release recapture

Answer 4

No births or deaths or migration - pop size is constant
There’s enough time for the organisms to distribute themselves (no assumption they redistribute uniformly tho)
The mark isn’t rubbed off
(Size of the total area isn’t required )

Question 5

Physiological Adaptations of pioneer species

Answer 5

Ability to photosynthesise
Resistant to high light intensity
Ability to fix nitrogen from the atmosphere
Rapid germination of seeds

Question 6

Interspecific and infraspecific competition differance

Answer 6

Inter = diff species compete for same resource
Intra= same species compete for a mate and same resources

Question 7

Carrying capacity

Answer 7

Max population an ecosystem can support

Question 8

Niche

Answer 8

Organisms role within an ecosystem .each species occupies its own one

Question 9

Ecosystem

Answer 9

A community and the non living components of an environment

Question 10

Community

Answer 10

All populations of different species in the same area at the same time

Question 11

When investigating populations what must you do with calculations

Answer 11

Round up or down as talking about numbers of animals

Question 12

Less harsh abiotic factors =

Answer 12

Larger range of species and each species will have a larger pop size

Question 13

Why will the prey population peak at a higher point

Answer 13

The predators are further along the food chain so whatever there eating contains less energy so to gain enough energy from there food they have to eat more numbers of prey compared to the predator population

Question 14

Niche separation

Answer 14

If occupy different niches

Question 15

Types of line transects

Answer 15

Interrupted belt transect and a belt transect (quadrant at every position on line)

Question 16

3 ways of collecting data in investigating population sizes

Answer 16

Local frequency
Density
Percentage cover

Question 17

Local frequency

Answer 17

Count the number of squares with the species present
100 squares - ?/100=?% show as percentage
Repeat x30 and calculate a mean % and this = estimate for entire field

Question 18

Density

Answer 18

Number of species present in a given area
Work out how many quadrants fit in field (divide area by size of quadrat)
X this by number of individuals in the quadrat = number of species in entire field

Question 19

Percentage cover

Answer 19

Estimate of how many full squares out of 100 are completely covered by species

Question 20

Ecology

Answer 20

The study of the inter relationships between organisms and their environment

Question 21

Micro habitats

Answer 21

Within each habitat there are smaller units with their own microclimate

Question 22

Competitive exclusion principle

Answer 22

No 2 species occupy the same niche, some may appear similar but their nesting habits or aspects of their behaviour will be different or they have have different levels of tolerance to pollutants or shortage of o2

Question 23

Limiting factors on populations growth

Answer 23

Availability of food, light, water, oxygen and shelter
And the accumulation of toxic waste, disease and predators