Topic 6: Inheritance, Variation & Evolution - Subtopic 3: The Development of Understanding of Genetics & Evolution

Question 1

What does Darwin’s theory of natural selection state?

Answer 1

• Individuals in a species show wide range of variation caused by difference in genes/mutation
• Individuals with characteristics most suited to environment had higher chance of survival and reproduce
• Alleles that code for advantageous characteristic is passed on to offspring at higher rate
• Over generations, beneficial characteristic become more common in population and species changes/evolves

Question 2

What did the idea of natural selection become known as?

Answer 2

Survival of the Fittest

Question 3

How did Charles Darwin propose the theory of evolution by natural selection?

Answer 3

• Result of observations on a round-the-world expedition
• Backed by years of experimentation and discussion linked to developing knowledge of geology and fossils

Question 4

Why was the theory of evolution by natural selection only gradually accepted and what was the controversy?

Answer 4

• Controversy around revolutionary new ideas
• Challenged idea that God made all animals and plants
• Insufficient Evidence
• Mechanism of inheritance and variation not know until 50 years later
• Theory developed over time

Question 5

What was Lamarck’s theory of evolution?

Answer 5

• French scientist 19th Century
• Characteristic becomes better and stronger, others not used gradually disappear
• Beneficial characteristic passed to offspring

Question 6

Who developed the theory of speciation?

Answer 6

Alfred Russel Wallace

Question 7

What is speciation?

Answer 7

Evolutionary process in which populations evolve to become new distinct species

Question 8

What is allopatric speciation?

Answer 8

1) 2 Populations of Same Species
2) Physical Barrier separates populations, Geographical Isolation
3) Adapt to new environments
4) Development of new species that can’t interbreed

Question 9

What is sympatric isolation?

Answer 9

No geographical barrier but are isolated through reproductive groups
- Rarer method where two populations don’t interbreed

Question 10

What are fossils?

Answer 10

Remains/Signs of organisms from thousands of years ago, found in rocks

Question 11

What are the 4 categories of fossil?

Answer 11

1) Hard Parts of animals that don’t decay easily
2) Parts of organism replace by other materials (Mineralisation)
3) Preserved traces of organisms e.g. footprints
4) Parts of organism that have not decayed because one or more conditions for decay aren’t present

Question 12

What do fossils allow us to see?

Answer 12

Changes in species over time

Question 13

What are issues with fossils for evidence for evolution?

Answer 13

1) Incomplete Fossil Records
2) Soft-Bodied Organism not going to form fossils, decay
3) Lost due to type of rock
4) Can be damaged

Question 14

What are the three evidences for evolution?

Answer 14

• Fossils
• Bacteria (Anti-Biotic Resistance)
• Extinction

Question 15

How is bacteria an evidence for evolution?

Answer 15

• Some strains of bacteria are resistant
• Non- Resistant killed by penicillin
• Resistant bacteria survive
• Reproduce and pass on their adaptations to their offspring

Question 15

How should doctors prevent resistant bacteria?

Answer 15

• Not prescribe antibiotics inappropriately (treating non-serious or viral infections)
• Finish course of antibiotics so all bacteria are killed and none survive to mutate from resistant strains

Question 16

What is extinction?

Answer 16

• No remaining individuals of a species alive so can’t reproduce

Question 17

What can lead to extinction?

Answer 17

• New Predators
• New Competitors
• New Pathogens
• Change in Environment
• Catastrophic Events

Question 18

How is extinction evidence for evolution by natural selection?

Answer 18

Due to the existence of fossils of extinct animals, this demonstrates animals not well- adapted didn’t survive, reproduce or pass on beneficial characteristics

Question 19

Name the Classification System

Answer 19

Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 20

How are binomial names made up?

Answer 20

Made up of Genus (Capitalised) and Species (lowercase) of the species

Question 21

What was added in the 80s to the Classification System and by who?

Answer 21

• Layer above kingdom called domain
• Developed by Carl Woese

Question 22

What are the 3 Domains?

Answer 22

• Eurkayota (Animalia, Plantae, Fungi, Protists)
• Prokaryota (Bacteria)
• Archae (Ancient Bacteria)

Question 23

What is classification?

Answer 23

Grouping of living things

Question 24

What are the 5 Kingdoms?

Answer 24

- Animal - Plants - Fungi - Bacteria - Protists

Question 25

Who created the Classification System?

Answer 25

Swedish Botanist Carl Linnaeus

Question 26

What is competition?

Answer 26

Rival between living things for resources, mates etc.

Question 27

What is adaptation?

Answer 27

- Species become fitted to environment over time

Question 28

What is a species?

Answer 28

Group of organisms which look similar and mate to produce fertile offspring

Question 29

When is it described that speciation has occurred?

Answer 29

Populations of the same species become so different that they are unable to interbreed and produce fertile offspring