inheritance

Question 1

what is an allele

Answer 1

different forms of the same gene

Question 2

dominant

Answer 2

allele of a gene that is always expressed in the heterozygous genotype

Question 3

recessive

Answer 3

allele that is not expressed in the phenotype when a dominant allele of the gene is present

Question 4

genotype

Answer 4

alleles an organism has for a certain characteristic eg:BB, homozygous dominant

Question 5

phenotype

Answer 5

how a gene is expressed. the ‘appearance’ of an organism resulting from its genotype

Question 6

homozygous

Answer 6

genotype with the same alleles of a gene, eg: AA or aa

Question 7

heterozygous

Answer 7

genotype with different alleles of a gene, eg:Aa

Question 8

codominant

Answer 8

if 2 alleles are expressed in the same phenotype- they are called codominant

Question 9

polygenic inheritance

Answer 9

when many characteristics are controlled by 2 or more genes working together’

Question 10

what is an example of polygenic inheritance

Answer 10

human skin colour

Question 11

why do the offspring from sexual reproduction vary genetically

Answer 11

huge variation in gametes, so it is random in which fertilisation takes place (RANDOM FERTILISATION)

Question 12

list three ways how twins are identical caused by genetics

Answer 12

-eye colour
-DNA
-height

Question 13

list three ways how twins are identical caused by environment

Answer 13

-personality
-weight
-hair colour

Question 14

what is the shape of DNA

Answer 14

double helix shape
-made of subunits and nucleotides

Question 15

what is the strand of a DNA molecule that codes for the making of proteins in a cell

Answer 15

the template strand

Question 16

how many bases code for 1 amino acid and what is it called

Answer 16

-3
-triplet code

Question 17

protein is made in the cytoplasm-in the ribosomes, DNA holds the genetic code for the protein in the nucleus but cannot leave the nucleus-how is this solved

Answer 17

genetic code is copies and transferred out the nucleus by RNA

Question 18

what base does RNA contain instead of thymine

Answer 18

uracil

Question 19

what sugar does RNA contain instead of deoxyribose

Answer 19

ribose

Question 20

is an RNA molecule bigger or smaller than DNA

Answer 20

smaller

Question 21

what are the three forms of RNA

Answer 21

-messenger mRNA
-transfer tRNA
-ribosomal rRNA

Question 22

where does transcription take place

Answer 22

nucleus

Question 23

where does RNA polymerase bind to

Answer 23

a region of non coding DNA in front of a gene

Question 24

what happens to the DNA when RNA polymerase moves along one of the strands of DNA

Answer 24

the DNA strands unzip

Question 25

what does mRNA use as a template so it can be made

Answer 25

the coding DNA in the gene

Question 26

base pairing between the DNA & RNA ensures what

Answer 26

MRNA is complementary to the gene

Question 27

what happens when the mRNA is made

Answer 27

the mRNA molecule moves out of the nucleus and joins with a ribosome in the cytoplasm

Question 28

where does transcrpition take place

Answer 28

nucleus

Question 29

what process happens when the mRNA is bound to the ribosome

Answer 29

translation

Question 30

what does the transfer RNA bring to the ribosome

Answer 30

amino acids

Question 31

I terms of the tRNA structure, what is the anticodon

Answer 31

-complementary to the codon of the amino acid -pairing of codon and anticodon makes sure amino acids are brought to the ribosome in the correct order

Question 32

what happens when the amino acids are joined together

Answer 32

a protein is made -protein is a specific shape which determines the function

Question 33

what is a nucleotide made of

Answer 33

-nitrogenous base -sugar molecule -phosphate group

Question 34

what are the main points of natural selection

Answer 34

-variation of species -due to random mutation -survival -reproduce -pass on favourable allele

Question 35

who came up with theory of natural selection

Answer 35

Charles Darwin

Question 36

who discovered the first antibiotic and what was it

Answer 36

Alexander flemming- penicillin

Question 37

how does a bacterium become resistant to penicillin

Answer 37

random mutation

Question 38

how to bacteria reproduce passing on the allele (resistance)

Answer 38

asexually

Question 39

what is a mutagen

Answer 39

increases the likelihood of a mutation happening

Question 40

what is are two examples of a mutagen

Answer 40

-cigarettes -ionising radiation