biodiversity and genetic variation

Question 1

What is the definition of population?

Answer 1

a group of individuals of the same species that live in the same place and can interbreed

Question 2

What is the definition of species?

Answer 2

a group of similar organisms that can reproduce to produce fertile offspring. Have the same genes but vary in alleles

Question 3

What is the definition of gene pool?

Answer 3

the total number of alleles in a particular population at a specific time

Question 4

What is the definition of allele frequency?

Answer 4

the number of times an allele occurs within a gene pool

Question 5

explain artificial classification

Answer 5

divides organisms according to differences that are useful at the time.

Based on analogous characteristics (such as colour, size)

where they have the same function but do not have the same evolutionary origins

Question 6

What is the definition of an index of diversity?

Answer 6

the relationship between the species richness and the number of individuals in each species

Question 7

explain phylogenic classification

Answer 7

based upon the evolutionary relationships between organisms and their ancestors

, classifies species into groups using shared features derived from their ancestors,

arranges the groups into a hierarchy. Partly based o homologous characteristics

Question 8

Why is genetic variation important?

Answer 8

• Conditions change all the time
• Populations showing more genetic variation are more likely to have the combinations of alleles required to survive the new conditions
• populations with little variation are more vulnerable to new diseases and climate changes
• these better-adapted individuals are more likely to survive, breed and pass on their advantageous allele to their offspring.

Question 9

What is the definition of species diversity?

Answer 9

number of different species and the number of individuals of each species in one community

Question 10

Why do biologists like to classify living things?

Answer 10

• better communication between scientists, avoids confusion
• organise them into more manageable groups

Question 11

What is taxonomy?

Answer 11

the theory and practice of biological classification

Question 12

What are the two types of classification

Answer 12

artificial classification

phylogenetic classification

Question 13

What are the characteristics and importance of courtship behaviour?

Answer 13

• it is species-specific- only members of the same species will do and respond to that courtship behaviour allowing for members of the same species to recognise each other, preventing interbreeding and making reproduction more successful
• identifies a mate that is capable of breeding
• form a pair bond = stays with each other to raise children
• synchronized mating = so it takes place when there is a maximum probability if the sperm and egg meeting
• Brings member of the opposite sex into breeding state = needs to make sure partner is in the physiological state that allows breeding to occur

Question 14

What is classification?

Answer 14

the organisation of living organisms into groups

Question 15

What is the definition of biodiversity?

Answer 15

variety in the living world

Question 16

What is the definition of ecosystem diversity?

Answer 16

range of habitats within a particular area

Question 17

What is the definition of species richness?

Answer 17

number of different species within community

Question 18

What are the different types of adaptions?

Answer 18

• Anatomical - structural features of an organism that increase its chance of survival
• Physiological- processes happening inside an organism
• Behavioural adaptions - ways that an organism acts that increase its chance of survival

Question 19

How does selection pressure drive natural selection?

Answer 19

not all offspring can survive and therefore must compete. Those with a selective advantage are more likely to survive, reproduce and pass on their favourable alleles

Question 20

What is intraspecific competition and how does this drive natural selection?

Answer 20

Competition within the species, so the better adapted survive only and are more likely to reproduce

Question 21

What is selection pressure?

Answer 21

environmental factors that limit the population of a species

Question 22

What are the different types of selection

Answer 22

Stabilising selection

Direction selection

Question 23

explain direction selection

Answer 23

Due to a change in the environment, the normal phenotype is no longer the most advantageous,

less common organisms with more extreme phenotypes are selected for

allele frequency shifts towards the extreme phenotypes and evolution occurs

Question 24

explain stabilizing selection

Answer 24

selection for the norm or the average.

This results in a decrease in frequency of the alleles at either extremes of the normal distribution and increase in the average alleles

Question 25

Describe the principles of natural selection

Answer 25

1. Random mutation can result in new alleles of a gene and increase genetic variation within a population
2. Selective pressures create struggle for survival
3. The new allele of a gene might benefit its possessor, as they may be better adapted to deal with selective pressures, leading to increased reproductive success and increased chance of survival
4. A greater proportion of the next generation inherit the advantageous allele
5. As a result, over many generations, the new allele increases in frequency in the population