Genetic Diversity And Clasification

Question 1

What is genetic variation?

Answer 1

The difference in DNA base sequence between individuals of the same population

Question 2

What is genetic diversity?

Answer 2

The number of different alleles of genes within a population

Question 3

What advantages does a high genet diversity of a population offer?

Answer 3

Ability to adapt to changes in the environment, allowing NATURAL SELECTION

Question 4

Describe how natural selection results in the development of new characteristics?

Answer 4

Random mutations lead to the formation of new alleles of a gene (variation)
The allele codes for a specific characteristic that can lead to a survival advantage due to SELECTIVE PRESSURES (in the environment) like competition for food, mates
This enables organisms to survive and reproduce passing on the advantageous allele to the offspring
Overtime the frequency of the advantageous allele within the population increases (causes evolution of species to become better adapted to their environment)

Question 5

What is directional selection?

Answer 5

When environmental conditions change, natural selection favours individuals with one EXTREME PHENOTYPE suited to the new condition who survive and pass on their genes
Overtime the mean of the population favours the EXTREME characteristic

Question 6

Give and explain an example of directional selection

Answer 6

Antibiotic resistance
- bacteria with a mutation allowing them to survive in the presence of antibiotics will reproduce
- and he frequency of his allele will increase and the population will shift to have greater antibiotic resistance

Question 7

What is stabilising selection?

Answer 7

When environmental conditions remain the same
Individuals closest to the mean are favoured (increase modal trait) and any new/extreme characteristics are selected against
Results in LOW DIVERSITY

Question 8

Give an example of stabilising selection?

Answer 8

Birth weight of babies

Question 9

What is disruptive selection?

Answer 9

Favouring individual with both extreme characteristics (starts speciation)

Question 10

Give an example of disruptive selection?

Answer 10

Darwin’s finches and their different shaped/size beaks
- Extreme characteristics favoured causing formation of new species

Question 11

What are the three types of adaptations and give examples?

Answer 11

Anatomical (body structure) - oily fur
Physiological (bodily processes) - venom production
Behavioural (actions) - hibernation

Question 12

Define species?

Answer 12

A group of similar organisms that can interbreed to produce fertile offspring

Question 13

What is taxonomy?

Answer 13

Taxonomy is the science of classifying and naming organisms based on their characteristics and evolutionary relationships.

Question 14

What is phylogeny ?

Answer 14

The study of evolutionary relationships between organisms

Question 15

How are organisms grouped in a phylogenetic classification system?

Answer 15

Organisms are grouped based on homologous characteristics that have the SAME EVOLUTIONARY ORIGINS in a hierarchy of graphs with no overlap

Question 16

What is a hierarchy?

Answer 16

Groups within groups without a overlap

Question 17

What is the classification hierarchy ?

Answer 17

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 18

What system is used to name species?

Answer 18

Binomial naming system

Question 19

How does he binomial naming system work?

Answer 19

Genus species
- genus has a capital letter the species name doesn’t
- Underlined/italics
- Abbreviation after full (G. species)

Question 20

What is artificial classification?

Answer 20

Divides species into groups based on analogous characteristics that have the same FUNCTION but a different EVOLUTIONARY ORIGIN

Question 21

What is phylogenetic classification?

Answer 21

Divides species into groups based on homologous characteristics that have the similar EVOLUTIONARY ORIGINS but a different FUNCTION

Question 22

How are phylogenetic relationships determined?

Answer 22

Structural similarities
DNA = more similar the more closely related the organisms
Fossil records

Question 23

What is courtship behaviour?

Answer 23

A sequence of actions which is unique to species as it’s genetically coded for by genes

Question 24

What is the importance of courtship behaviour?

Answer 24

Enables recognition of their own species and the opposite sex (to produce fertile offspring and prevent interbreeding)
Identify a sexually mature mate (capable of breeding) and form a pair bond (increases survival of offspring)
Synchronise mating behaviour

Question 25

Give an example of some courtship behaviours?

Answer 25

Bower birds - construct structures decorate with sticks, leaves and stones
Puffer fish - plough brought sand creating ridges they decorate with shells
Bird of paradise- fan delicate wings and bob/strut

Question 26

How can courtship behaviour aid classification?

Answer 26

The more closely related the species the more similar their courtship behaviour

Question 27

Define classification?

Answer 27

The process or arranging organisms into groups

Question 28

How can we clarify evolutionary relationships/identify genetic diversity between species?

Answer 28

Frequency of observable characteristics (gene difference reflected in phenotype)
The base sequence of DNA
The base sequence of mRNA = higher % base sequence similarity = more closely related
The amino acid sequence of protein
Immunology (albuiem) higher weight of precipitate the more closely related

Question 29

What is a cladogram?

Answer 29

A cladogram is a diagram that shows the evolutionary relationships among different species based on shared characteristics
(Most recent common ancestor)

Question 30

What is the concept of speciation.

Answer 30

Speciation is the process by which new species arise from existing ones due to genetic divergence and reproductive isolation.