exam 2

Question 1

evolution

Answer 1

1. have elvoled by natural selection;
2. variation / varied / vary in shape / colour;
3. originally there would have been mutation / mutated;
4. not seen by predators / not eaten / camouflaged / not attacked / eq;
5. survive / survival / survival (of the fittest); 6. reproduce / produce offspring / eq;
6. pass on allele / gene / DNA;

Question 2

diffusion

Answer 2

Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration
The bigger the difference in conc the faster the rate of diffusion
Liquid and gas particles are free move about randomly

Question 3

selective breading

Answer 3

Process:
From existing stock select the stock with best charcteristcs
Bread them with each other
Select the best of the offspring bread them together
Continue the process over serval generations and the traits get stronger and stronger for farming better yield will be produced.

Question 4

restriction enzymes

Answer 4

enzymes recognise specific sequences of DNA and cut out the DNA

Question 5

Ligase enzymes

Answer 5

joining up two pieces of DNA

Question 6

Dominant allele

Answer 6

always determines the characteristics in a phenotype

Question 7

answer to 1 a

Answer 7

testis

Question 8

answer to 1 b

Answer 8

anther

Question 9

answer to 2a

Answer 9

1

Question 10

The acrosome contains digestive enzymes

Answer 10

to break down outer layer of the ovum

Question 11

describe the route taken by the sperm cell from when iyt enters the woman’s body to the site of fertilisation of thug

Answer 11

it goed psst the cervix after entering the vagina up the uterus lining through the fallopian tube where is meets the egg

Question 12

why the father determines the sex of baby

Answer 12

females only have xx which is what makes it female where as the males have the xy chromosomes contains the Y chromosomes which can determine weather the baby is a boy

Question 13

answer to 2f

Answer 13

man a has a higher amount of sperm cells

man a sperm cells has no deformity

Question 14

answer 2 g

Answer 14

45 %

Question 15

difference between dominant allele and a recessive allele

Answer 15

dominant allele always determines the chartists in a phenotype while recessive allele
A recessive allele is only expressed if the individual has two copies and does not have the dominant allele of that gene

Question 16

explain albinos recessive or dominant

Answer 16

it is a recessive allele as it is largely not shown and even though there is one affected it docent show in all the children +

Question 17

suggest an advantage of using afrtical insemination to fertile

Answer 17

it is safer for the cow

Question 18

what is meant by transgenic

Answer 18

Transgenic means that they contain genes transferred from other species

Question 19

give role of restrictive and ligase

Answer 19

Restriction enzymes recognise specific sequences of DNA and cut the DNA at this point
Ligase enzymes joining up two pieces of DNA

Question 20

explain the factors that affect the rate of movement in and out substance into and out

Answer 20

surface area to volume ratio - rate of all increased when there is a larger surface area
distance: the shorter the distance the faster the diffusion
temperature: move faster when they get warmer increaser them
conc gardent: in and out of cells faster when there a big con only increases rate of dif and osmos and not active transport
size of particles: smaller particles will diffuse faster

Question 21

describe the differences between diffusion and active transport

Answer 21

the diff between diff and active transport diffusion moves with the conc gardent whereas At goes against it. furthermore at requires energy while diff dent and is a passive process

Question 22

what leads to variation

Answer 22

male gamete and female gamete then combine at random during fertilisation so the offspring inherits a random mixture of chromosomes from both parents
also mutation which is a random change that happens in a chromosome and mutations can be inheritented and cause alterations in the base pair

Question 23

rat question

Answer 23

since the rats are homozygous they have alleles are the same it is easy to spot any changes

Question 24

sperm mitrocidria question

Answer 24

realises energy needed for sperm to swim and fertilise egg