Definitions

Question 1

Species

Answer 1

Group of similar organism with the same genes that reproduce to produce fertile offspring

Question 2

Population

Answer 2

All the individuals of a given species living together in the same area at the same time

Question 3

Carrying Capacity

Answer 3

Maximum, equilibrium number of organisms of a particular species that can be supported in each stable environment. Birth rates and death rates are at equilibrium

Question 4

Community

Answer 4

All the individuals of all the species living together in the same area at the same time

Question 5

Habitat

Answer 5

Place where organisms live in an ecosystem

Question 6

Niche

Answer 6

Describes where an organism lives and what it does, including what it feeds on and how it interacts with other organisms and the environment.

Question 7

Why do two species not have the same niche?

Answer 7

They would compete and one would be more successful

Question 8

What happens where niches overlap?

Answer 8

Species have adaptations that outcompete. Different organisms may operate the same ecological niche whilst competing until one is eliminated.

Question 9

Types of quadrating

Answer 9

Density- actual count of all individuals- time consuming, most accurate, species may be difficult to count.
Percentage cover- area covered by one species is recorded as percentage of total area- used when there are too many individuals to count, over-laying species may occur
Frequency- proportion of quadrants that contain a particular species. Least accurate

Question 10

Random quadrating method - how many should be used?

Answer 10

Map area using two measuring tapes, use random number generator to lay quadrat.
Stop when there is little change, enough to carry out a statistical test and calculate a running mean.

Question 11

Systematic sampling

Answer 11

Transect- recording what touches the line at each point
Belt transect- two parallel lines, metre apart, record what’s found between the two lines.
Interrupted- one line, places quadrat at equally spaced sampling points and record abundance of species within quadrat,

Question 12

Succession

Answer 12

Series of a change within a community. Starts from barren rock to climax community

Question 13

Pioneer species

Answer 13

The organisms that first colonise an area

Question 14

Sere

Answer 14

Complete succession from pioneer community to climax community, a seral stage has its own distinctive community of organisms.

Question 15

Climax community

Answer 15

Final stage- stable, formed depending on abiotic factors

Question 16

Hostility and abiotic environment / diversity

Answer 16

Low diversity and abiotic factors dominate the distribution of species
Non-living parts of the environment
Relationship between number of organisms and number of species within a community.

Question 17

Process of succession

Answer 17

Colonisation by names pioneer
Change in environment
Enables other named species to colonise
Change in diversity
Stability increases
Climax community is represented by named species
Secondary succession- happens after a forest fire etc. begins with pioneer seres

Question 18

Biodiversity

Answer 18

The number of species and the number of individuals of each of the different species within one community

Question 19

Species richness

Answer 19

The number of different species within a community

Question 20

Genetic diversity

Answer 20

Difference in DNA

Question 21

Diversity
Index

Answer 21

N(N-1)/n(n-1)

Question 22

What info is required to calculate an index diversity

Answer 22

Number of species, number of Individuals in a species

Question 23

Explain why an index of diversity may be more of a useful measure of biodiversity

Answer 23

Also measures number of individuals of each species. Some species may be present in low/high numbers

Question 24

2 advantages of using an index of biodiversity rather than an indicator species

Answer 24

Don’t need to identify each species, index considers number of organisms of each species

Question 25

Economic arguments for maintaining biodiversity

Answer 25

High species diversity, the more stable the eco-system
Pharmaceutical use,commercial products, tourism, agriculture and saving local forest communities

Question 26

Farming reduces species diversity

Answer 26

Natural plants etc lost when land is cleared, may reduce variety of food sources, habits and niches, growth of specific crops and growth of other species is controlled or stopped, pesticides etc are used to kill unwanted species.

Question 27

Hierarchy

Answer 27

Domain, kingdom, phylum,class, order, family, genus, species

Question 28

Phylogenetic vs binomial naming system

Answer 28

Bi= first word- genus name. Second word- species name
Ph- all organisms evolved from shared ancestors- more closely related.

Question 29

Courtship behaviour and 2 ways it increases probability of successful mating

Answer 29

Attract a mate of the same species and opposite sex. Important to ensure reproductive success.
Attracts same species of opposite sex, indication of sexual maturity, stimulates release of gametes, form pair bond

Question 30

Classification methods

Answer 30

Base sequence of DNA/ mRNA and amino acid sequence of the proteins