B15: Genetics & Evolution

Question 1

What are 3 facts about natural selection?

Answer 1

Individuals within a species show a wide range of variation, individuals with characteristics most suited to the environment are most likely to survive and breed successfully and characteristics that have enabled these individuals to survive are passed on to the next generation

Question 2

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

Answer 2

The theory challenged the idea that God made all animals, there was insufficient evidence at the time and the mechanism of inheritance and variation was not known until 50 years after

Question 3

What are fossils?

Answer 3

Remains of organisms from millions of years ago which are found in rocks

Question 4

What are 3 ways fossils can be formed?

Answer 4

From parts of organisms that have not decayed because one or more conditions needed for decay are absent, when parts of organisms are replaced by minerals as they decay and as preserved traces of organisms, such as footprints

Question 5

What does soft-bodied mean?

Answer 5

They have left a few traces behin

Question 6

Why can’t scientists be certain of how life began on earth?

Answer 6

Because traces were destroyed mainly by geological activity

Question 7

What is extinction?

Answer 7

The process of remaining individuals in a species die

Question 8

How can the rate of development antibiotic resistant strains be reduced?

Answer 8

Doctors should not prescribe antibiotics inappropriately, patients should complete a full course of antibiotics so bacteria are killed and the agricultural use of antibiotics should be restricted

Question 9

What are disadvantages to the development of antibiotics?

Answer 9

They are costly and slow

Question 10

How are living things classified?

Answer 10

Depending on their structure and characteristics in a system

Question 11

What is the order of classification?

Answer 11

Kingdom, phylum, class, order, family, genus, species

Question 12

How are organisms named?

Answer 12

Binomial system of genus and species

Question 13

What are organisms divided into in the ‘three-domain system’?

Answer 13

Archea (primitive bacteria in extreme conditions), bacteria and eukaryota (protists, fungi, animals and plants)

Question 14

How were closely related species separated?

Answer 14

Geographical barriers such as a wide river

Question 15

What are similarities between Alfred Wallace and Darwin?

Answer 15

Both spent time on Islands and published books on findings and

Question 16

Why is antibiotic resistance evidence for natural selection?

Answer 16

Bacteria reproduce rapidly and mutations occur during reproduction. If a mutated bacterium is resistant, it will survive exposure to the antibiotic and reproduce. The bacterium will represent the original ancestor of a new resistant strain

Question 17

What causes slower extinctions? What causes faster ones?

Answer 17

Geological and atmospheric changes happening overtime. Abiotic factors

Question 18

What can volcanic eruptions change levels of?

Answer 18

Soil pH, carbon dioxide and light

Question 19

Who performed breeding experiments on pea plants in 19th century?`

Answer 19

Gregor Mendel

Question 20

What was used to categorise species in the Linnaean system?

Answer 20

Appearance

Question 21

What 3 traits did Mendel study?

Answer 21

Height, colour of flower and colour of pea

Question 22

Describe how antibiotic resistance arises?

Answer 22

Person takes antibiotics, some bacteria get random mutations making them less susceptible to the antibiotic. Antibiotic kills unresistant bacteria and the resistant strains now have more room to colonise

Question 23

What is Alfred Wallace best known for?

Answer 23

Studying warning colouration in animals, (e.g. Golden Birdwing Butterfly) and speciation

Question 24

Why may speciation occur?

Answer 24

Due to isolation and natural selection

Question 25

What is a species?

Answer 25

A group of organisms that are able to interbreed and produced fertile offspring

Question 26

What is the advantage of using the binomial system to name species?

Answer 26

It lets scientists discuss individual species and each species has a unique name

Question 27

What do evolutionary trees show?

Answer 27

The evolutionary relationships between the organisms being studied