Diversity Classification Variation

Question 1

Gene mutation

Answer 1

Change in the base sequence of chromosomes

Question 2

Mutagenetic agents

Answer 2

Increase the rate of gene mutation

Question 3

Factors increasing genetic variation

Answer 3

Independent segregation of homologous chromosomes
Crossover of homologous chromosomes
Random fertilisation of haploid gametes

Question 4

Genetic diversity

Answer 4

Number of different alleles of a gene in a population

Question 5

Genetic bottleneck

Answer 5

Event causing a big reduction in a population
Reduces number of different alleles in the gene pool
Reduces genetic diversity
Survivors reproduce and a larger population is created from few individuals

Question 6

Founder effect

Answer 6

Few organisms from a population start a new colony
Small number of different alleles in the initial gene pool
Higher incidence of genetic disease
Can be a result of migration/ geographical separation

Question 7

Aseptic techniques

Answer 7

Disinfect surfaces
Contaminated utensils in beaker of disinfectant
Sterile equipment
Discard safely after use
Work near bunsen flame to produce un upwards current of air to remove microbes from the culture
Minimise time spent with lid of agar off
Flame neck of container of broth (of bacteria) to force air out of container

Question 8

Community

Answer 8

All the populations of different species in a habitat

Question 9

Biodiversity

Answer 9

Variety of living organisms in an area

Question 10

Variation

Answer 10

Differences that exist between individuals

Question 11

Hierarchy

Answer 11

Smaller groups within larger groups
With no overlap between them

Question 12

Species

Answer 12

Group of similar organisms able to reproduce to give fertile offspring

Question 13

Species richness

Answer 13

Measure of the number of different species in a community

Question 14

Index of diversity

Answer 14

Both the species richness and the abundance of each species are taken into account in this measure

Question 15

Techniques in clarifying evolutionary relationships

Answer 15

Genome sequencing- comparing DNA sequences
Comparing amino acid sequence
Immunological comparisons- similar proteins will also bind the same antibodies

Question 16

Gene technologies in assessing genetic diversity

Answer 16

Comparing dna base sequences of the same gene to determine number of different alleles of that gene in the population
Comparing mRNA base sequences/ amino acid sequences due to different alleles

Question 17

Non disjunction

Answer 17

Failure of separation of homologous chromosomes in meiosis 1

Question 18

Phylogenetic classification

Answer 18

Arranges species into groups based on their based on their evolutionary origins and relationships
Smaller groups placed within larger groups
No overlap
Hierarchy

Question 19

Agricultural practices that reduce biodiversity

Answer 19

Woodland clearance- reduces number of trees and number of different species, destroys habitats, causes migration
Hedgerow removal
Pesticides- also affects predators of the insects it kills
Herbicides- reduced diversity and affects organisms feeding on the weeds
Monoculture- reduces biodiversity and supports fewer organisms

Question 20

How can genetic diversity within or between species be determined

Answer 20

Comparing frequency of measurable or observable characteristics
Comparing base sequence of DNA/mRNA/amino acid sequences

Question 21

Quantitative investigations of variation involve

Answer 21

Collecting data from random samples
Calculating mean and the SD of that mean
Interpretation

Question 22

Describe how organisms are grouped in a phylogenetic classification system

Answer 22

Hierarchy with no overlaps/ smaller group within laser groups
Grouped according to the evolutionary origins/ relationships/ history