Evolution of Species

Question 1

What are mutations?

Answer 1

Spontaneous, random changes to the genetic material of an organism, this means the order of the bases in DNA is different or the number or structure of chromosomes are different.

Question 2

What are mutations the only source of?

Answer 2

New alleles

Question 3

What happens if the order of bases is different?

Answer 3

This may result in a change of the protein structure coded by the DNA

Question 4

What can a tiny change to a vital gene do?

Answer 4

Prevent an important protein from being built correctly

Question 5

When can mutations be serious?

Answer 5

They can be serious depending in where the mutation occurs

Question 6

What are gene mutations?

Answer 6

Miniscule mutations that affect the base sequence of DNA

Question 7

What are chromosome mutations?

Answer 7

Large scale mutations which can increase or decrease the chromosome number or can change the structure of a chromosome

Question 8

Why are mutations important?

Answer 8

They are the only source of new alleles in a species, the source of variations which can be crucial for survival

Question 9

Give environmental factors of mutations

Answer 9

Radiation (this includes gamma rays and UV rays) and chemicals (this includes agent orange, bromine and nicotine)

Question 10

Why is adaptation important?

Answer 10

New alleles that are produced by a mutation that can cause an organism to change.
If these changes are an advantage to survival then the organism becomes better adapted to their environment.

Question 11

What is adaptation?

Answer 11

An inherited characteristic that makes an organism well suited to surviving in its environment/niche

Question 12

What are the three types of adaptations?

Answer 12

Physiological
Structural
Behavioural

Question 13

Name the four steps of natural selection

Answer 13

Species produce more offspring than the environment can sustain

Natural selection or survival of the fittest occurs when there are selection pressures

The best adapted individuals in a population survive to reproduce, passing on the favourable alleles that confer the selective advantage

These alleles increase in frequency within the population

Question 14

What is natural selection?

Answer 14

Natural selection is the process through which populations of living organisms adapt and change.

Question 15

What is selection pressures?

Answer 15

Anything from list of abiotic and biotic factors impacting biodiversity

Question 16

Give examples of selection pressures

Answer 16

Changing environment (temperature, light, PH)

Introduction of disease

Change in predators/grazing

Introduced species

Competition

Question 17

What can be used to explain high speed evolution of insecticide resistance in mosquitos?

Answer 17

Natural selection

Question 18

What is speciation?

Answer 18

A process forming two or more species from one original

Question 19

What is a species?

Answer 19

A group of organisms that can reproduce with one another in nature and produce fertile offspring.

Question 20

Explain the four step by step of speciation

Answer 20

After part of a population becomes isolated by an isolation barrier, which can be geographical, ecological or behavioural.

Different mutations occur in each sub-population.

Natural selection selects for different mutations in each group, due to different selection pressures.

Each sub-population evolves until they become so genetically different that they are two different species.

Question 21

What do geographical features such as rivers, deserts, oceans and mountain ranges do?

Answer 21

Isolate groups

Question 22

When do ecological isolation barriers occur?

Answer 22

2 sub-populations live in the same area and could technically meet and breed, but they don’t as they live in different areas of the habitat

Question 23

Give examples of ecological isolation barriers

Answer 23

Hot and cold areas of the habitat
Humid and dry
Different Ph (different soil types)
Salinity
Altitude

Question 24

When does behavioural speciation occur?

Answer 24

When 2 sub-populations live in the same area, and could technically meet and breed, but don’t due to changes in behaviour

Question 25

Give examples of behavioural speciation

Answer 25

Different courtship behaviours

Diurnal/nocturnal

Question 26

What are the four steps of speciation?

Answer 26

Isolation
Mutation
Natural selection
New species

Question 27

What does each sub-population have?

Answer 27

It’s own gene pool

Question 28

What happens even if the two populations are joined together?

Answer 28

They will not be able to produce fertile offspring