6 - inheritance beginning of topic

Question 1

why do scientists have to understand the human genome

Answer 1

1. identify links between dif diseases
2. find better solutions
3. trace global migration - anscestors

Question 2

what are non coding genes for

Answer 2

control weather or not the gene is expressed
they dont code for a specific amino acid

Question 3

protein synthesis process

Answer 3

• mRNA copys the code form DNA in the nucleus and acts as a messenger bc too big
• carries the code of the correct amion acids in the correct order to the ribosomes
• now protiens can be made in the ribosomes

Question 4

functions of proteins

Answer 4

1. enzymes
2. hormones
3. structural proteins

Question 5

whats a mutation and how can they occur and effect

Answer 5

• change in the sequence of the DNA bases in a gene - amino acids change and so protein changes
• inhertited or sponaneously or by radiation expsoure
• normally dont have any effect - sometimes effect can be good or bad

Question 6

3 types of mutations

Answer 6

1. insersion
2. deletions
3. substitution

Question 7

about sexual reproduction

Answer 7

• offspring genetically DIFFERENT to parents
• mum and dad produced gametes by MEIOSIS
• mum and dad have 23 choromosones each and then fertilise together and create offspring with full set of 46 chromosomes

Question 8

definition of sexual reproduction

Answer 8

fusion of male and female gametes causing the offspring to contain a mixture of their parents genes

Question 9

about Asexual reproduction

Answer 9

• one parent
• divides by MITOSIS
• new cell has is genetically idenitcal

Question 10

definition of Asexual reproduction

Answer 10

there is only one parent and off spring are gentically identicle to parent - clone bc there is no genetic variation

Question 11

process of meiosis

Answer 11

1. cell DUPLICATES its genetic info - chromosones arrange themselves into pairs
2. FIRST CELL DIVISION - chromosones line up in the cnetre of the cells
3. the pairs are PULLED APART - new cell now only has one copy of each chromosone
4. SECOND DIVISION - chromosones line up in the centre again and then are pulled apart

Question 12

what are the products of meiosis

Answer 12

4 gametes each with a single set of chromosones all genetically different

Question 13

why is sexual reproduction better than asexual

Answer 13

• variation
• higher survival chance
• can do natural selection and adapt better
• seletcive breeding

Question 14

why is Asexual reproduction better than sexual

Answer 14

• one needs one parent
• less energy bc dont have to mate
• faster
• lots of identical offspring can be made in favourable conditions

Question 15

men and women chronomsone letters

Answer 15

XX - woman
XY - man

Question 16

about cystic vibrosis

Answer 16

• thick sticky muscus in air passages and pncrease
• recessive

Question 17

about polydactyly

Answer 17

• extra fingers or toes - not serious
• dominant

Question 18

how are embryos screened

Answer 18

• embryos are fertilised in a lab and then implanted into mothes womb
• but before you implant it you can remove a cell from each embryo and analyse its genes to detect for inhertited disorders

Question 19

for and against embryo screening

Answer 19

FOR
- prejudice against ppl with genetic problems
- designer baby
- v £££££££
- bad alleles get destroyed - unethical

AGAINST
- helps ppl stop suffering
- treating them might cost gov loads of £££ and time
- there are laws to stop it going too far eg designer baby

Question 20

mendels 3 important conclusions

Answer 20

1. characteristics in plants are determined by “heredity units”
2. heredity units are passed onto offspring UNCHANGED from parents - one unit from each parent
3. can be dominant or recessive

Question 21

explanation for what Mendel showed in his pea plant experiment

Answer 21

the height characteristic in pea plants was determined by separately inherited hereditary units passed on from each parents

Question 22

how does fungi reproduce sexually and asexually

Answer 22

sexually - for variation
asexually - to release spore

Question 23

how do plants reproduce sexually and asexually

Answer 23

sexually - produce seeds
asexually - eg dafodils when their bulbs divide

Question 24

how do malaria parasites reproduce sexually and asexually

Answer 24

sexually - in the host mosquito
asexually - in the host human

Question 25

what are chromosomes called from mother and father

Answer 25

maternal chromosones
paternal chromosones