Chapter 14

Question 1

what are the two types of variation?

Answer 1

environmental and genetic

Question 2

what cause genetic variation?

Answer 2

the fusion of two sets of DNA - one from mother, one from father

Question 3

examples of characteristics influenced only by genes (3)

Answer 3

eye colour
inherited diseases
blood group

Question 4

what causes environmental variation?

Answer 4

the conditions and environment an organism lives and grows in

Question 5

definition of environmental variation

Answer 5

differences between organisms of the same species due to differences in their surroundings

Question 6

definition of genetic variation

Answer 6

the combination of two sets of DNA leading to different characteristics in the offspring

Question 7

examples of characteristics caused by environmental variation 3

Answer 7

suntan
education
height of plants

Question 8

what are most characteristics caused by?

Answer 8

both environmental and genetic variation

Question 9

what is natural selection?

Answer 9

the organisms with the most suitable characteristics for an environment survive and pass on these successful alleles

Question 10

what is a mutation?

Answer 10

a change in the genetic code

Question 11

what does evolution through natural selection suggest?

Answer 11

only the most well adapted to an environment will survive and pass on their alleles, leading to changes in the characteristics of organisms

Question 12

4 key steps in natural selection

Answer 12

mutation of gene - advantage of survival - breed - pass on genes

Question 13

what will a mutation very rarely lead to?

Answer 13

a new phenotype

Question 14

theory of evolution

Answer 14

all of today’s species have evolved from simple life forms that started to develop billions of years ago

Question 15

example of mutation in action

Answer 15

the Malpeque Bay oysters
came down with a disease that killed many of them but a few had a mutation of a disease resistant gene so went on to breed all oysters with this gene

Question 16

what is the phenotype caused by?

Answer 16

genes

Question 17

what is speciation?

Answer 17

development of a new species

Question 18

how does speciation occur?

Answer 18

the phenotype of an organism changes so much that a completely new species is formed

Question 19

what is extinction?

Answer 19

no individuals of a species remain

Question 20

3 reasons for extinction

Answer 20

new predator
new disease
catastrophic event

Question 21

what is selective breeding?

Answer 21

breeding two specific parents to produce offspring with a desired characteristic

Question 22

examples where selective breeding is used 3

Answer 22

cows producing more milk
crops with disease resistance
pets with good temperament

Question 23

basic process of selective breeding

Answer 23

select parents with desired characteristic
breed them together
select the offspring with the best characteristic and breed these
continue until all offspring have trait

Question 24

problems with selective breeding 2

Answer 24

inbreeding causing health problems

new diseases/changes in environment - no variation to adapt

Question 25

what is inbreeding?

Answer 25

when two animals that are closely related are bred

Question 26

what is genetic engineering?

Answer 26

altering the genetic material of an organism by transferring a gene so it has a desired characteristic

Question 27

what is used to cut out a gene in genetic engineering?

Answer 27

an enzyme

Question 28

what is the removed gene inserted into?

Answer 28

a vector

Question 29

what does the vector do in genetic engineering?

Answer 29

it is used to insert the gene into the organism

Question 30

process of genetic engineering?

Answer 30

the gene is isolated and cut out from one organism it is inserted into a vector the vector inserts the gene into the desired cells the organism grows with the characteristic

Question 31

examples of vectors used in genetic engineering 2

Answer 31

bacteria | viruses

Question 32

examples of where genetic engineering has been used 3

Answer 32

bacteria making insulin GM crops for a higher yield gene therapy

Question 33

what is gene therapy?

Answer 33

swapping faulty genes in ill people with working ones to cure the disease

Question 34

why are crops genetically modified? 2

Answer 34

they have increased yields | frost and pest resistant

Question 35

main advantage to increased crop yields

Answer 35

can feed growing global population

Question 36

advantages to GM crops 3

Answer 36

increased yield more nutrients can grow in difficult climates

Question 37

problems with GM crops 3

Answer 37

can affect natural wildflowers we don't fully understand impact on human health transplanted genes may mix into environment to form herbicide resistant weeds

Question 38

what is a clone?

Answer 38

something that is genetically identical to its parents

Question 39

main way of cloning plants

Answer 39

tissue culture

Question 40

process of cloning by tissue culture

Answer 40

a small group of plant cells are put in a growth medium and grow into clones of their parents

Question 41

advantages to tissue culture 3

Answer 41

made quickly grown all year round preserve rare plants

Question 42

alternative way of cloning plants

Answer 42

cuttings

Question 43

process of cloning by cuttings

Answer 43

cuttings are taken from parent plant and grown to make many clones

Question 44

main way of cloning animals

Answer 44

embryo transplants

Question 45

process of embryo transplants

Answer 45

sperm cells taken from prize bull egg cells taken from cow the two are combined to form an embryo these cells are unspecialised so any can become a whole cow the embryo is split apart and the cells transplanted into surrogate mothers

Question 46

what is adult cell cloning?

Answer 46

when a whole new animal is produced from one cell if an adult animal

Question 47

process of adult cell cloning

Answer 47

taking unfertilised egg cell and remove nucleus another nucleus is taken from an adult body cell the nucleus is inserted into the empty egg cell the egg cell is stimulated to divide this creates an embryo which is then implanted into an adult female to grow

Question 48

most famous example of adult cell cloning

Answer 48

Dolly the sheep

Question 49

benefits of adult cell cloning 3

Answer 49

animals that are already producing useful proteins in their milk can be cloned save animals from extinction bring back extinct species

Question 50

problems of adult cell cloning 3

Answer 50

reduced variety in a population - unable to adapt to change loss of embryo life 'designer babies'

Question 51

benefits of genetic modification in medicine 3

Answer 51

potential to cure inherited diseases insulin and growth hormones can be made from bacteria or fungi genetically modified mice used to develop cures

Question 52

benefits of genetic modification in agriculture 3

Answer 52

crops can grow in difficult climates increased yield pest or frost resistance