investigating populations & succession

Question 1

SPECIES:

Answer 1

A species is a group of closely related individuals, which are capable of interbreeding and
producing fertile offspring.

Question 2

POPULATION:

Answer 2

A population is all the individuals of a given species living together in the same area
at the same time.

Question 3

CARRYING CAPACITY:

Answer 3

Carrying capacity is the maximum, equilibrium number of organisms of a
particular species that can be supported indefinitely in each stable environment. Birth rates and
death rates are in equilibrium.

Question 4

COMMUNITY:

Answer 4

A community is all the individuals of all the species living together in the same area
at the same time.

Question 5

HABITAT:

Answer 5

Habitat is the place where an organism lives within an ecosystem. (Abiotic)

Question 6

NICHE:

Answer 6

A niche describes where an organism lives and what it does (its role). This includes what
it feeds on and how it interacts with other organisms and the environment.

Question 7

Define Biotic factors and an example

Answer 7

is a living factor which affects the distribution of an organism
e.g Competition between organisms, predation
and disease

Question 8

Define Abiotic factors and an example

Answer 8

Climatic factors such as temperature, light
intensity, and wind speed.
Physical factors such as soil / water ph, water
level in soil, slope of the land, etc.

Question 9

Define abiotic factors and an example

Answer 9

is a non-living factor which affects the
distribution of an organism
e.g Climatic factors such as temperature, light
intensity, and wind speed.
Physical factors such as soil / water ph, water
level in soil, slope of the land, etc.

Question 10

Outline a method ecologists could use to determine plant species richness at one site

Answer 10

grid with coordinates selected using random number generator
use of quadrat
identify plant species in each quadrat

Question 11

What term is used to describe populations of different species living in the same habitat?

Answer 11

community

Question 12

Describe how you would investigate the distribution of marram grass from one
side of the dune to the other.

Answer 12

1) Create a transect by placing a tape measure from one side of the dune to the other.
2) Use systematic sampling by placing a quadrat down next to the tape measure every metre for example.
3) Measure the percentage cover of marram grass in each quadrat.

Question 13

Describe how you could estimate the size of a population of sundew in a small Marsh

Answer 13

-two tape measures perpendicular
-random number generator to get coordinates
-count the number of sundews in the quadrat
-repeat to get a large sample
-find a mean number of sundews and multiply by the area of the Marsh

Question 14

The ecologists could have used the mark-release-recapture method to estimate the
number of one species of fish in the lake. Describe how.

Answer 14

Capture sample, mark and release;
Take second sample and count marked organisms;
Estimated population size: no. in 1st sample x no. in 2nd sample
————————————————–
no. marked in sample 2

Question 15

The ecologists found that each species of fish had adaptations to its niche. One of these
adaptations was the shape of its mouth.
Suggest how the shape of mouth is an adaptation to its niche.

Answer 15

With different mouth eats
different food / has different way
of feeding / specific mouth shape
for specific food;
2. Competition between
species/interspecific competition
is reduced;