B1

Question 1

what do genes do? how do they do this?

Answer 1

.carry out instructions that control how you develop and function
.they do this by telling the cells to make the protines needed for your body to work

Question 2

what does DNA stand stand for?

Answer 2

deoxyribonucleic acid

Question 3

what are chromosomes made out of? where are they found?

Answer 3

.lengths of DNA coiled a nd packed together

.found in the nuclei of the body’s cells

Question 4

what are the stands of DNA made up of?

Answer 4

4 chemicals called bases as well as phosphate groups and sugar molecules.

Question 5

what does the order of bases in the DNA strand determine?

Answer 5

the order of amino acids in a protine

Question 6

what are the two groups of protines and what do they do?

Answer 6

.functional protines- enable the body to function (enzymes,antibody, hormones)
.structural protines- gives the body structure,ridgity, strength. (keratin in skin)

Question 7

for a particular characteristic what can you describe a person by?

Answer 7

.genotype

.phenotype

Question 8

what is a genotype?

Answer 8

.his or her genetic make up
.refers to the whole of the individuals genes, or the genes specific characteristic
.for example dimples
.genotype is usually written as two letters (DD)

Question 9

what is a phenotype?

Answer 9

.describes his or her observable features
.for example build, or a single characteristic
.it depends on a persons genes
.may also be affected by the environment

Question 10

list these in smallest to largest...
.nucleus
.DNA
.chromosomes 
.Base
.gene
.cell

Answer 10

.cell
.nucleus
.chromosomes
.DNA
.gene
.base

Question 11

what is the name when the egg and sperm cells have joined together?

Answer 11

zygote

Question 12

name one type of mutation that can occur?

Answer 12

a person with an extra chromosome will have down syndrome.

Question 13

why are siblings always different (except identical twins)?

Answer 13

.the combination a chromosomes in an egg or sperm will always be different
.in and egg chromosome 1 could have been inherited by the mother, while chromosome 2 and 3 could have been inherited by the father

Question 14

what are alleles?

Answer 14

.the different forms in which the genes controlling a characteristic can occur
.for example for dimples; one allele is for the presence of dimples and one allele is for the lack of dimples

Question 15

If the two alleles of the gene are identical, what is this person said to be?

Answer 15

homozygous

Question 16

if the two alleles are different, what is the person said to be?

Answer 16

heterozygous

Question 17

what are alleles?

Answer 17

the different form of a gene that controlled a certain trait

Question 18

what are the two different types of alleles?

Answer 18

.dominant

.recessive

Question 19

what can you use a punnet square for?

Answer 19

.showing genetic crosses

.finding the probability of two parents producing different types of offspring

Question 20

what is a family tree diagram useful for?

Answer 20

when tracing genetic disorders such as Huntington desise over generations

Question 21

which parents is our sex determining gene?

Answer 21

23

Question 22

what diseases are more likely to be present in men?

Answer 22

.haemophilia( blood clotting)

.red-green clout blindness

Question 23

is Huntingtons desise recessive or dominant? what are some of the symptoms?

Answer 23

.Dominant disorder

.uncontrollable shaking, memorie loss, inability to concentrate, and mood changes

Question 24

is cystic fibrosis a recessive or dominant gene? what do the symptoms include?

Answer 24

.recessive

.the production of thick gluey mucus, makes digesting food difficult, breathing problems

Question 25

wait is genetic screening used for?

Answer 25

.to check for particular disorders | .the blood spot test is used on most new born babies to see if they have a rare genetic disorders

Question 26

what is genetic testing used for?

Answer 26

diseases that run in the family

Question 27

how is genetic testing carried out during pregnancy?

Answer 27

.amniocentesis (collecting cells from the developing fetus which are present in amniotic fluid) .chorinic villus sampling (testing a sample of cells taken from the placenta)

Question 28

what is pre-implantation genetic diagnosis?

Answer 28

screening embryos prior to implantation and only using healthy embryos

Question 29

how can plants reproduce asexually?

Answer 29

.using runners (for example strawberries) | .producing bulbs (for example daffodils)

Question 30

what are some advantages of producing clones/ asexual reproduction ?

Answer 30

.successful characteristics are seen in of spring | .asexual reproduction is useful where plants and animals live in isolation

Question 31

what is a disadvantage of producing clones?

Answer 31

.there is no genetic variation | .the population could be wiped out

Question 32

how are clones produced?

Answer 32

.the nucleus from a body cell is extracted and inserted into an egg cell that has had its nucleus removed. this gives the egg cell a full set of genes without having been fertilised .the embryo is inserted into a sticker surface mother

Question 33

explain a process called differentiation?

Answer 33

a human embryo develops from a single cell. this cell divides over and over again as the baby develops. most of these cells become specilised to do different jobs

Question 34

where can stem cells be used?

Answer 34

.the testing of new drugs .understanding how cells become specilised in the early stages of a human development by the switching on and off of particular genes .renewed damaged or destroyed cells in spinal injuries, heart desise, alzhimers disease and parkinsons disease.