Classification & Variation

Question 0

What phylum do vertebrates come under?

Answer 0

Chordata

Question 1

What is the classification system?

Answer 1

Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 2

What Kingdom is bacteria in?

Answer 2

Prokaryote

Question 3

Why are protoctists different from prokaryotes?

Answer 3

They have a nucleus

Question 4

Give an example of a protoctist

Answer 4

Algae

Question 5

Are animals heterotrophs or autotrophs?

Answer 5

Heterotrophs

Question 6

What is a ‘poikilotherm’?

Answer 6

An organism who’s body temperate depends on the outside environment

Question 7

How do you know when organisms are of the same species?

Answer 7

They can interbreed to produce fertile offspring

Question 8

In a binomial system, what is the first part of the two part name?

Answer 8

Genus

Question 9

What type of variation is when a plant gets yellow leaves?

Answer 9

Environmental

Question 10

What type of variation is skin colour?

Answer 10

Both

Question 11

With continuous variation, most organisms will have a height around…

Answer 11

The mean

Question 12

How do you know when variation is discontinuous?

Answer 12

There are distinct categories

Question 13

How have angler fish adapted to deep sea life?

Answer 13

Rod shaped spine which emits light to attract prey

Question 14

How has the rat tail fish adapted to deep sea life?

Answer 14

A big mouth which scoops up particles of food along the seabed

Question 15

What is chemosynthesis?

Answer 15

When organisms can make their own food using chemical energy

Question 16

What process enables bacteria to survive off the chemicals in hydrothermal vents?

Answer 16

Chemosynthesis

Question 17

What does a low surface area compared to volume of a polar bear do to help it survive in a polar region?

Answer 17

Reduces heat loss

Question 18

Why do polar bears have a thick layer of blubber?

Answer 18

For insulation and an energy store when food is scarce

Question 19

Why do polar bears have wide feet?

Answer 19

To spread their weight so they don’t break thin ice or sink into snow

Question 20

Why do penguins huddle together?

Answer 20

To conserve heat

Question 21

Why do penguins have a streamlined body?

Answer 21

To reduce water resistance so they can swim fast and catch fish

Question 22

Who came up with the theory of natural selection?

Answer 22

Charles Darwin

Question 23

Describe the process of natural selection

Answer 23

1) there is variation between organisms of the same species due to mutations in genes and inherited variation
2) most organisms produce more offspring than will survive
3) populations have to compete for food, water and mates to survive
4) individuals with characteristics suited to their environment means a better chance of survival
5) this means they can survive breed and pass on their advantageous genes
6) those less suited are less able to compete for survival and so are less likely to survive and pass on their genes through reproduction
7) over time there will be a higher number of individuals with the beneficial characteristics so eventually the poorly adapted characteristics are lost and the species has evolved.

Question 24

What process drives evolution?

Answer 24

Natural selection

Question 25

What two main things support evolution?

Answer 25

DNA research | Resistant organisms

Question 26

What happened with warfarin to support the theory of evolution?

Answer 26

1) warfarin poison used to kill rats 2) a certain gene made rats resistant to warfarin so those rats survived, reproduced and passed on their advantageous gene 3) there are now warfarin resistant populations of rats

Question 27

How did the scientific community validate evidence about evolution?

Answer 27

Publishing their work in scientific journals Peer reviewing their findings Holding scientific conferences/meetings to present an discuss their work

Question 28

What is 'speciation'?

Answer 28

The development of a new species

Question 29

When does speciation occur?

Answer 29

When populations of the same species become so different that they can no longer interbreed to produce fertile offspring

Question 30

Explain the process of speciation.

Answer 30

1) geographical isolation between populations 2) different environmental conditions on either side of the barrier between populations 3) populations adapt to new environments- different characteristics will be advantageous on either side of the barrier so natural selection will occur 4) eventually individuals from different populations will have changed so much that they won't be able to breed with each other to produce fertile offspring. The two groups have become separate species

Question 31

What are chromosomes?

Answer 31

Long lengths of DNA coiled up

Question 32

What is a gene?

Answer 32

A short section of DNA

Question 33

What is an allele?

Answer 33

A different version of the same gene

Question 34

Where is DNA found?

Answer 34

In the nucleus of a cell

Question 35

What does a genetic diagram show?

Answer 35

The possible genes of offspring

Question 36

What does 'homozygous' mean?

Answer 36

An organism has two alleles for a particular gene that are the same

Question 37

What does 'heterozygous' mean?

Answer 37

An organism has two alleles for a particular gene that are different

Question 38

What is the allele for a characteristic that is shown?

Answer 38

The dominant allele

Question 39

How can an organism display a recessive characteristic and why?

Answer 39

Both it's alleles must be recessive because the dominant allele overrules the recessive one

Question 40

What is a genotype?

Answer 40

The alleles you have

Question 41

What is a phenotype?

Answer 41

The characteristic you have

Question 42

Which type of allele causes cystic fibrosis?

Answer 42

Recessive

Question 43

With cystic fibrosis, what is a carrier?

Answer 43

Someone who has only one copy of the allele for the disorder so doesn't suffer from it

Question 44

What are the results of having cystic fibrosis?

Answer 44

Body produces a sticky mucus in the air passages, gut and pancreas

Question 45

What are the symptoms of cystic fibrosis?

Answer 45

Breathing difficulties Lung infections malnutrition Fertility problems

Question 46

How can a child inherit cystic fibrosis?

Answer 46

Both parents must be carriers or sufferers

Question 47

If both parents carry the allele for cystic fibrosis but do not suffer from the disorder, what is the chance of a child inheriting the disorder?

Answer 47

1 in 4

Question 48

How can genetic disorders be detected?

Answer 48

By analysing a cell's genes - known as screening

Question 49

What does sickle cell anaemia do to red blood cells?

Answer 49

Red blood cells become sickle shaped so have a smaller surface area which means they carry less oxygen

Question 50

What are the symptoms of sickle cell anaemia?

Answer 50

Tiredness Painful joints and muscles Fever Anaemia