Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOLOGY > Natural Selection and Genetic Modification > Flashcards

Natural Selection and Genetic Modification Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

what is evolution

A

the slow and continuous change of organisms’ inherited characteristics from one generation to the next

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

explain how evolution occur by natural selection

A
  1. Individuals in a population show genetic variation as they have different alleles
  2. Predation, competition for resources and disease act as selection pressures which means they affect an organisms chance of surviving and reproducing
  3. Individuals with characteristics that make them better adapted to the selection pressures have a better chance of surviving
  4. This means alleles responsible for the useful characteristics are more likely to be passed onto the next generation
  5. Some individuals will be less adapted to the selection pressures and will be less able to compete, survive and reproduce
  6. Beneficial characteristics become more common in the population over time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are antibiotics

A

drugs designed to kill bacteria or prevent them from reproducing

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

how does the emergence of resistant organisms support the theory of evolution

A

the emergence of antibiotic resistance proves evidence for evolution . Antibiotic reisstance makes the bacteria better adapted to an environment in which a selection pressure (antibiotics) are present. As a result, antibiotic resistance has become more common in the population over time

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

what is evidence for evolution

A

fossils

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

how do fossils prove evidence for evolution

A

by arranging fossils in chronological order, gradual changes in organisms can be observed which shows how organisms have changed and developed

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

what did Charles Darwin do that led him to the theory of evolution

A

he spent 5 years on a voyage around the world. He noticed there was variation in member of the same species and that those with characteristics most suited to the environment were more likely to survive and pass on the characteristics to offspring.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what did Wallace realise that led him to the theory of evolution

A

Wallace realised that warning colours are used by some species to deter predators from eating them - an example of a beneficial characteristic that had evolved by natural selection

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

what is the influence of the theory of evolution on modern biology

A

it has helped us classify organisms based on how closely related they are

we now understand the importance of finishing the course of drugs to prevent resistant bacteria spreading

We now understand the importance of genetic diversity and how it helps populations adapt to changing environments

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

what is “Ardi”

A

a fossil of the species Ardipithecus ramidus which is 4.4 million years old

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

what are the features of “Ardi”

A

the structure of her feet suggest she climbed trees as she had an ape like big toe

she also had large arms and short legs

her brain size was about the same as a chimpanzee

the structure of her legs suggests she walked upright

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is Lucy

A

a fossil of the specied Australopithecus afarensis, which is 3.2 million years old

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

what are the features of “Lucy”

A

she had arched feet, more adapted to walking than climbing

size of arms were in between an apes and humans

brain was slightly larger than Ardi’s but still around the same size as a chimpanzee

the structure of Lucy’s legs bones and feet suggest she walked upright but more efficiently than Ardi

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

what did Richard Leaky find

A

different Australopithecus and Homo species, including Turkana boy which is 1.6 million years old

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

what are the features of “Turkana boy”

A

he had short arms and long legs much like a human and his brain size was much larger than Lucy’s - similar to a human

The structure of his legs and feet suggest he was even better adapted to walking upright than Lucy

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

What stone tools did Homo Habilis use (between 2.5-1.5 million years ago)

A

they made simple stone tools called pebble tools by hitting rocks togehter to make sharp flakes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what stone tools did Homo erectus use (between 2 and 0.3 million years ago)

A

they sculpted rocks into shapes to produce more complex tools like simple hand axes which are used to hunt, dig, chop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what stone tools did Homo neanderthalenis use (300,000 and 25,000 years ago)

A

they used flint tools, with sharp,pointed edges and wooden spears

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what stone tools did Homo Sapiens use (200,000 years ago to now)

A

more complex pointed tools including fish hooks, needles and arrowheads were used and flint tools were widely used as well

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how can you date stone tools and fossils

A

looking at the structural features of the tool or fossil

using stratigraphy

carbon-14 dating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is stratigraphy

A

the study of rock layers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is a limb

A

an arm, leg or wing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is a digit

A

the end part of a limb e.g. a finger or a toe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is a pentadactyl limb

A

a limb with 5 digits

25
Q

how does the anatomy of the pentadactyl limb prove evidence for evolution

A

the similarity in bone structure proves evidence that all species with a pentadactyl limb have all evolved from a common ancestor. If they had all evolved from different ancestors, it would be highly unlikely that they would share a similar bone structure

26
Q

what are the 5 kingdoms

A

animals
plants
fungi
prokaryotes - all single celled organisms without a nucleus
eukaryotes

27
Q

what are kingdoms divided into to make smaller groups

A

kingdom
phylum
class
order
family
genus
species

28
Q

what are the 3 dominions

A

eukarya
archaea
bacteria

29
Q

what is selective breeding

A

when humans artificially select the plants or animals that are going to breed so that the genes for particular characteristics remain in the population

30
Q

what are examples of selective breeding

A

animals that produce more meat or milk
crops with disease resistance
dogs with a good, gentle temperament
plants that produce larger fruit

31
Q

what is the basic process of selective breeding

A
  1. From your existing stock, select the ones with the desirable characteristics
  2. Breed them with each other.
  3. Select the best of the offspring and breed them together
  4. Continue this process over several generations and the desirable trait gets stronger and stronger and eventually all offspring will have the characteristic
32
Q

what are the benefits of selective breeding

A

higher yields
selective breeding can be used in medical research

33
Q

what are the risks and negatives of selective breeding

A

it reduces the gene pool and number of allele in a population

inbreeding can cause health problems because there is more chance of organisms inheriting harmful genetic defects

ethical considerations as animals are deliberately bred to havbe negative characteristics for medical research

if a new disease appears they are all likely to be killed by it if one dies as there is not much variation so less chance of resistant alleles

34
Q

what is tissue culture

A

when cells are grown on or in an artificial growth medium

35
Q

what is the growth medium

A

usually agar jelly

36
Q

what are clones

A

genetically identical organisms

37
Q

why do scientists use tissue culture

A

to produce lines of clones all with the same beneficial features

38
Q

explain the process of tissue culture

A
  1. First choose the plant you want to clone, usually based on its characteristics
  2. Remove several pieces of tissue from the parent plant
  3. Grow the tissue on a growth medium containing nutrients and growth hormones
  4. As tissues produce shoots and roots they can be moved to potting compost to carry on growing
39
Q

what are the advantages of tissue culture

A

it is easy
plants can be made very quickly
doesn’t take up a lot of space
can be grown all year

40
Q

what is genetic engineering

A

transfer of a gene from one organisms genome into another organism’s genome in order to introduce a desirable characteristic

41
Q

what is genetic engineering used to do

A

produced GM crops
produce human insulin from bacteria to treat diabetes

42
Q

explain the process of genetic engineering

A
  1. The DNA that is going to be transferred is cut out with a restriction enzyme. The cut leaves one of the DNA strands with unpaired bases - this is called sticky ends
  2. The SAME restriction enzyme is used to cut open the vector DNA. It could be a plasmid or a virus.
  3. The vector DNA and the DNA you are inserting are left with complementary sticky ends . They are mixed together with ligase enzymes .
  4. Ligase joins the sticky ends togheter to produce recombinant DNA
43
Q

explain the process of genetic engineering

A
  1. The DNA that is going to be transferred is cut out with a restriction enzyme. The cut leaves one of the DNA strands with unpaired bases - this is called sticky ends
  2. The SAME restriction enzyme is used to cut open the vector DNA. It could be a plasmid or a virus.
  3. The vector DNA and the DNA you are inserting are left with complementary sticky ends . They are mixed together with ligase enzymes .
  4. Ligase joins the sticky ends together to produce recombinant DNA
  5. The recombinant DNA is inserted into other cells such as bacteria
  6. The cells can now use the inserted gene to make the protein it codes
44
Q

what do restriction enzymes do

A

recognise specific sequences of DNA and cut the DNA at these points

45
Q

what is a vector

A

something used to transfer DNA into a cell

46
Q

what are the benefits of genetic engineering

A

lots of medicines can be produced easily
higher crop yields

47
Q

what are the negatives of genetic engineering

A

we do not know what the effect modifying its genomes will have on the organism as some do not survive

transplanted genes may get out into the environment

genetically modified crops could adversely affect food chains or even human health

48
Q

what are the benefits of genetically modifying plants

A

increase the yield of food
crops can be engineered to contain additional nutrients which can help deficiency diseases

49
Q

what are the disadvantages and concerns about genetically modifying crops

A

people are not hungry due to a lack of food, but because it is too expensive

countries may become dependant on companies who sell GM seeds

GM crops won’t survive if there is poor soil

concerns that the long term effects of exposure to GM crops on human health and environment are not yet known

50
Q

what is Bt

A

a type of bacterium that produces a toxin that kills many of the insect larvae that are harmful to crops

51
Q

what are the benefits of the Bt toxin

A

improved crop yield
reduces need for chemical pesticides

52
Q

risks of Bt crops

A

insects that feed on the crops will eventually become resistant
farmers may still use pesticides

53
Q

what are other methods of increasing food production

A

fertilisers
biological control

54
Q

what are the benefits of using fertilisers

A

they contain minerals which are essential for plant growth and replace nutrients lost from the soils to previous crops

55
Q

what are the negatives of using fertilisers

A

cause eutrophication

56
Q

what does biological control do

A

use other organisms to reduce pest numbers

57
Q

what are the benefits of biological control

A

long lasting effects
less harmful to wildlife
cheaper

58
Q

what are the negatives of biological control

A

new organisms can cause problems as they might become pests themselves

BIOLOGY (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions