Evoltion

Question 1

What is a theory

Answer 1

An idea that best fits the current evidence that we have

Question 2

How does fossilisation occur

Answer 2

An animal or plant dies —> the bones are left behind —> the skeleton of the animal gets covered by sand and clay —> gets mineralised by tje pressure of rock formation above —> fossil left behind

Question 3

Why is fossilisation so rare

Answer 3

the bones have to be relatively untouched by bacteria, and the clay has to cover it before any damage is done to it

Question 4

Evidence for evolution

Answer 4

-> fossil records
-> homologous structures
-> analogous structures
-> vestigial structures
-> comparative embryology
-> molecular biology
-> observed examples of

Question 5

How does fossil records show evolution

Answer 5

We are able to compare the fossils of the same species with existing bones today
By putting the fossils in chronological order
We can see how the species changed over time by observing the gradual changes in the organism

Question 6

What are homologous structures

Answer 6

Parts of an organism body that are similar in structure but are found in different species and serve a different function

Question 7

What are analogous structures

Answer 7

Parts of an organism that performs the same function that evolved independently in unrelated species in order to adapt to the environment

Question 8

What are vestigial structures

Answer 8

Vestigial structures are structures found in an organism that are no longer have any known function

Question 9

What is comparative embryology

Answer 9

It is the process of examining the embryos of animals in different species

Question 10

What is molecular biology

Answer 10

Comparing the sunmiularies and differences of DNA in unrelated species

Question 11

How did fossils records prove evolution

Answer 11

We are able to compare the fossils with the animals ofthe same species that are still alive today

We are able to see how the species have changed overtime

Question 12

How do homologous structures prove evolution

Answer 12

They show that all of the soecies have had a common ancestors and have evolved separately to fit their environment

Question 13

How do analogous structures prove evolution

Answer 13

They show how evolution allows animals of a different species to develop similar structures in order to survive in their environment

Question 14

How do vestigial structures prove evolution

Answer 14

Vestigial structures prove evolution because they were inherited from ancestors but no longer serve a useful purpose, showing the organism has changed over time.

Question 15

How does comparative embryology prove evolution

Answer 15

embryos of different species show similar stages of development and homologous structures).

This shows they were inherited from a common ancestor, even though the adult forms are different

Question 16

Explain how natural selection leads to evolution (4 marks)

Answer 16

There is variation in a species
Organisms with alleles favourable to selection pressures are more likely to survive
They are more likely to survive and pass alleles to offspring
Over long periods of time the beneficial alleles become dominant

Question 17

Phylogenetics

Answer 17

Classification using evolutionary links
Based on evolutionary branch that organism comes from

Question 18

Artificial classification

Answer 18

Classificatio based in characteristics you can see eg phenotype

Question 19

Natural classification

Answer 19

Groups organisms based on anatomical and anscestral features

Question 20

Order of natural classification

Answer 20

Kingdom

Phylus

Class

Order

Family

Genus

Species

Classes get larger as you go up

Question 21

What does how fast a species is able to evolve depend on

Answer 21

How quickly it reproduces

Question 22

What happens when an organism has the advantages alleles

Answer 22

A hugher proportion of its offspring wilk inherit the advantageous alleles meaning they will have the phenotypes to help survive

Question 23

Examples of observed examples of evolution

Answer 23

Antibiotic resistance in bacteria

Question 24

How do bacteria evolve to become antibiotic resistant

Answer 24

They reproduce a lot and really fast

Hugher change kf a mutatiom being developed

Introduces new variants into populations

These variants could have the phenotype to resist antibiotics

Lives longer and produces more offspring