Variation and Evolution

Question 1

Example of symbiosis

Answer 1

Lichen

Question 2

Mutation

Answer 2

Spontaneous (or sudden change) in the structure/ amount of DNA

Question 3

Who came up with the theory of evolution ?

Answer 3

Charles Darwin

Question 4

Evolution

Answer 4

The way in which living things change genetically to produce new forms of life over long periods of time

Question 5

Theory of Natural Selection : 3 observations by Darwin

Answer 5

Observation 1 : overbreeding
Observation 2 : population numbers remain constant
Observation 3 : inherited variations occur in populations

Question 6

Theory of Natural Selection : conclusions

Answer 6

Conclusion 1 : there is a struggle for existence
Conclusion 2: natural selection

Question 7

Natural selection

Answer 7

The process by which those organisms either genetically controlled characteristics allow them to be well adapted to their environments will survive and reproduce to pass on their genes to following generations

Question 8

Fossil

Answer 8

The remains of something that lived a long time ago (or some indication of something that lived a long time ago)

Question 9

Examples of fossils :

Answer 9

Entire organisms, shells, bones, teeth, seeds

Question 10

Fossil evidence of evolution

Answer 10

To indicate that organisms have changed over time

Question 11

Fossil evidence for evolution factors :

Answer 11

Fossils can be aged
Fossils show changes when compared with modern organisms
The more modern fossils show increased complexity
Very often the fossil evidence can be linked to environmental change

Question 12

Evolution of the horse : 60 million years ago

Answer 12

Size of a fox

Question 13

Evolution of the horse : 30 million years ago

Answer 13

Larger (size of German Shepard)

Question 14

Evolution of the horse : 15 million years ago

Answer 14

Size of a Great Dane

Question 15

Evolution of the horse : 1 million years ago

Answer 15

Modern horse - about 1.6 m high

Question 16

Speciation

Answer 16

The production of new species as a result of evolution

Question 17

Mutagens

Answer 17

Agents that cause mutations

Question 18

Spontaneous mutations

Answer 18

Mutations that may arise naturally when DNA fails to produce exact copies of itself / when it fails to repair properly

Question 19

Carcinogen

Answer 19

A mutagen that causes cancer

Question 20

A gene (or point mutation)

Answer 20

A change in a single gene

Question 21

Allele (variation and evolution)

Answer 21

Altered gene

Question 22

Chromosome mutation

Answer 22

A large change in the structure or number of one or more chromosomes

Question 23

Classification

Answer 23

Means placing objects into groups based on similar characteristics

Question 24

Taxonomy

Answer 24

The science of classifying organisms

Question 25

Species (variation and evolution)

Answer 25

A group of similar organisms that are capable of naturally interbreeding with each other to produce fertile offspring

Question 26

Variation (evolution)

Answer 26

Within a species means that a group of successfully interbreeding organisms the individual members show different characteristics

Question 27

Aquired variation

Answer 27

Are not inherited but are learned or developed during life

Question 28

Inherited variation

Answer 28

Are controlled by genes e.g., blood groups, eye/hair colour

Question 29

Variations are because of :

Answer 29

The independent assortment of chromosomes

Question 30

Causes of inherited variations

Answer 30

Inherited variations arise as a result of sexual reproduction and mutations