4.2 Variation & modern examples of Evolution Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

(variation) what is variation?

A

differences in characteristics within and between species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

(variation) what is interspecific variation?

A

variation or differences between different species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

(variation) what is intraspecific variation?

A

differences between different organisms of the same species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

(variation) give an example of interspecific variation:

A

rat has four legs and fur

snake has no legs and no fur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

(variation) give an example of intraspecific variation?

A

people differ in height, eye colour and build

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

(variation) what are the two causes of variation?

A

environment

genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

(variation) give examples of environmental factors that can cause variation:

A
climate
diet
accident
culture
lifestyle
diseases 
resources
predators
war
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

(variation) how is the flower colour of hydrangeas affected by the environment?

A

soil acidity
acid - blue flowers
alkaline - pink flowers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

(variation) scars are an example of variation caused by what?

A

the environment

occur due to accident or disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

(variation) environment - a plant in the sun is more likely to do what?

A

grow than one in the shade

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

(variation) genetic variation can be due to what 5 factors?

A
alleles
mutation
meiosis
sexual reproduction
chance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

(variation) genes have different alleles, which produce what?

A

differences in characteristics e.g. there are 3 alleles for blood group depending on combination 1 of 4 groups can be produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

(variation) what are mutations?

A

changes in the DNA sequence which can affect the proteins coded for affecting characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

(variation) when can a mutation be passed onto the offspring and inherited?

A

if it occurs in the gametes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

(variation) how can variation occur in meiosis?

A

independent assortment of homologous chromosomes

crossing over

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

(variation) in sexual reproduction offspring inherits what, resulting in what?

A

genes from both parents

results in differences between parents and offspring

17
Q

(variation) how does chance result in genetic variation?

A

it is chance as to which gametes combine resulting I genetic variation between siblings

18
Q

(variation) how can height be determined by a combination of genetic and environmental factors?

A

you may inherit genes to grow tall

but if you’re malnourished you may not grow to this height

19
Q

(variation) how can skin colour be determined by a combination of genetic and environmental factors?

A

determined by genes in how much melanin your skin contains

skin darkens due to sunlight exposure

20
Q

(variation) what is continuous variation?

A

variation can take any value within a range - contained by multiple genes e.g. height

21
Q

(variation) what is discontinuous variation?

A

variation within specific categories - caused by a single gene e.g. blood group

22
Q

(modern examples) methicillin resistant staphylococcus aureus has developed what?

A

resistance to many antibiotics

23
Q

(modern examples) as bacteria reproduce rapidly what occurs quickly?

A

evolution

24
Q

(modern examples) bacteria’s DNA can be altered and in some instances leads to resistance to what?

A

methicillin

25
Q

(modern examples) these bacteria can survive and reproduce passing on what?

A

the resistance allele

26
Q

(modern examples) pre industrial revolution most peppered moths were what colour?

A

pale - camouflaged by tree bark

dark moths usually eaten

27
Q

(modern examples) during the industrial revolution what happened to the bark and then the peppered moths?

A

bark darker

darker moths camouflaged so less likely to be eaten so their population size rapidly increased

28
Q

(modern examples) now pollution levels have decreased and more trees are light coloured what is happening to the frequency of the pale allele?

A

increasing

29
Q

(modern examples) what are sheep blowflies?

A

lay their eggs around faecal matter around a sheep they hatch and cause sores

30
Q

(modern examples) in 1950s what was used to kill the blowflies and what did the blowflies develop after six years?

A

pesticide - diazinon

blowflies developed a high level of resistance

31
Q

(modern examples) what was not found in blowflies 70 years old?

A

this resistance

32
Q

(modern examples) there is a new strain of flavobacterium living in waste water from where?

A

factories producing nylon 6

33
Q

(modern examples) the strain of flavobacterium has evolved to do what?

A

digest nylon

34
Q

(modern examples) what was the flavobacterium mutation due to?

A

gene duplication frame shift mutation

35
Q

(modern examples) how is the mutation in the flavobacterium beneficial?

A

humans can use it to clear factory waste

bacteria provided with a new source of nutrients