Variation And Evolution

Question 1

What is variation

Answer 1

Differences in characteristics of individuals

Question 2

What is variation the result of

Answer 2

Differences in genetics

The environment

Or both

Question 3

What is evolution

Answer 3

Gradual change of inherited characteristics of biological populations over time

Question 4

What is speciation

Answer 4

The average phenotypes of two populations have changed so much that the two populations can no longer breed to produce fertile offspring. Two different species has been formed

Question 5

Why does speciation happen

Answer 5

Happen as a result of evolution

Natural mutations can create new alleles and 2 populations can behin to diverge

Question 6

Natural selection was proposed by

Answer 6

Charles Darwin

Question 7

How does natural selection happen

Answer 7

Within a population different individuals have genetic variation

Individuals possessing genes making them better adapted to the environment will have a greater chance of survival

Individuals with best chance of surviving are most likely to breed successfully

The characteristics for the increase in likelihood of survival are more likely to be passed onto next generation

Question 8

Selective breeding

Answer 8

When humans choose animals and crops to breed based on their genetic characteristics usually to promote desirable characteristics

Question 9

Selective breeding process

Answer 9

Choose parents which strongly display desired characteristic and breed them

From tye resultant offspring choose the offspring that displays the desired characteristic best

Repeat process of breeding and reselection over many generations until all offspring show desired characteristic

Question 10

Uses of selective breeding

Answer 10

In crops: disease resistance increases yield of product

Animals: animals that produce more milk or meat increase yield

Dogs: gentle natured domestic dogs are useful as theses animals must co live with humans

Flowers: Bigger and brighter flowers are more likely to be bought, increasing profit

Question 11

Dangers of selective breeding

Answer 11

Interbreeding

Reduce variation in species making it harder for them to adapt to environmental change

Question 12

Genetic engineering

Answer 12

Modifying an organism genome by introducing a gene from another organism to produce a desired characteristic

Question 13

Genetic engineering examples

Answer 13

Insulin producing gene can be inserted into bacteria who will then mass produce the insulin to treat people with diabetes

Lack of vitamin a can lead to blindness and a lot of community’s lacking in vitamin a ate lots of rice
Therefore a gene that produced vitamin a was taken from bacteria and added to rice

Question 14

Genetic engineering process

Answer 14

Emzyme used to Cut gene out of Chromosome

Same enzyme used to cut a vector( usually a bacterial plasmid)

Vector is used to insert gene into required cell

If gene is delivered into cell before specialisation all the cells in the developed organism will have the gene and show the characteristic

Question 15

Uses of genetic engineering

Answer 15

Transferring genes into animals

Transferring genes into plant

Transferring genes into bacteria

Question 16

Advantages of genetic modification

Answer 16

Genetic engineering: prevents inherited diseases
Improves food production efficiency

Genetically modified crops:
Increased yield
Provide nutrients often missing in diets

Question 17

Disadvantages about genetic moderation

Answer 17

Genetic engineering:
Uncertain long term effects
Unethical to move genes between species

Genetically modified crops:
Expect they will negatively impact wild flower and insect populations

Some think there will be long term effects of consumption

Decrease biodiversity

Question 18

Cloning plants using cuttings

Answer 18

Good parent plants are used as source of cuttings

A branch is cut off parent plant

Hormones are used to encourage roots to grow and the cuttings is then planted

These new plants are identical to the parent

Question 19

Cloning plants using tissue culture

Answer 19

Small groups of cells are taken from plant and placed in petri dish with plant food in it

Division of these cells results in formation of clone of parent

It’s quick, space sufficient and preserves rare species

Question 20

Cloning animals using embryo transplants

Answer 20

Devolving embryos can be split into smaller groups of cells before differentiation to give many smaller identical embryos which can then be pit in host mothers

Question 21

Adult cell cloning for cloning animals

Answer 21

Take unfertilised egg cell and remove nucleus

The egg cell is then injected with the nucleus of an adult body cell from the animal being cloned

An electric shocks given to the egg cell to stimulate it to divide

Once the embryo has grown into a larger ball of cells its implanted into a surrogate mother

The embryo ( a clone of the adult body cell) will continue to develop in the womb of the surrogate