The Organism In The Environment

Question 1

Define a population

Answer 1

The number of organisms of the same (or closely related) species in an area

Question 2

Define a community

Answer 2

Multiple populations (different organisms) living and interacting in the same area

Question 3

Define a habitat

Answer 3

The place where an organism lives

Question 4

Define an ecosystem

Answer 4

The interaction between a community of living organisms and their environment

Question 5

Define biodiversity

Answer 5

The variation shown by organisms in a given area

Question 6

Define biomass

Answer 6

Total mass of organisms in a given area

Question 7

Give the method for:

PRACTICAL- INVESTIGATE POPULATION SIZE OF AN ORGANISM IN TWO DIFFERENT AREAS USING QUADRATS

Answer 7

1. Use two tape measures to lay out a 10m x 10m survey area in a chosen habitat
2. Use a random number generator to create a set of coordinates to place your first quadrat
3. Count the number of the chosen plant species found within this quadrat
4. Estimate the population in your two survey areas using the equation
   ESTIMATED POPULATION SIZE = (TOTAL AREA/AREA SAMPLED) X TOTAL NUMBER OF SPECIES COUNTED
5. Repeat and average

Question 8

Give the method for

PRACTICAL- INVESTIGATE THE DISTRIBUTION OF ORGANISMS IN THEIR HABITATS AND MEASURE BIODIVERSITY USING QUADRATS.

Answer 8

1. Use two tape measures to lay out a 10m x 10m survey area in your chosen habitat
2. Use a random number generator to create a set of coordinates to place your first quadrat
3. Identify different plant species found in the quadrat.Count and record the number of individuals of each species in the quadrat.
4. Repeat steps 1-3 to take 9 more samples.
5. Estimate the population size of the different species using this formula:
   total area / area sampled x total number of individuals of each species counted
6. Repeat the procedure in another site and compare the results (number of different species and abundance of each species) to determine the differing degrees of biodiversity.

Question 9

Define an abiotic factor

Answer 9

A non living condition/ thing that influences or affects an ecosystem and the organisms in it.

Question 10

Give 7 abiotic factors

Answer 10

Light intensity
Temperature
Moisture levels/water supply
Soil pH + mineral content
Wind intensity + direction
CO2 levels
O2 concentration for aquatic animals.

Question 11

Define a biotic factor

Answer 11

A living condition/thing that influences or affects an ecosystem and the organisms in it

Question 12

Give 4 biotic factors

Answer 12

Availability of food
New predators
New pathogens
Competition