6.1.1

Question 1

What is a gene?

Answer 1

section of DNA that codes for a polypeptide

Question 2

What is a polypeptide?

Answer 2

chain of amino acids joined by peptide bonds

Question 3

What is a genome?

Answer 3

all the genetic material in an organism, including genes and non-coding DNA

Question 4

What is a protein?

Answer 4

1or more folded polypeptide chains

Question 5

What is a histone?

Answer 5

protein DNA wraps around to form chromatin. Allows DNA to be more compactly packaged

Question 6

What is transcription?

Answer 6

Process of copying DNA base sequence to produce a specific polypeptide chain

Question 7

What is a mutation?

Answer 7

change to the DNA bases / nucleotides

Question 8

What are gene mutations?

Answer 8

changes to the base sequences of genes in DNA

Question 9

What is a substitution gene mutation?

Answer 9

One or more bases are swapped for others

Question 10

What are the 3 types of substitution gene mutation?

Answer 10

Mis-sense
Non-sense
Silent

Question 11

What is insertion?

Answer 11

One or more bases are added into the sequence of the gene

Question 12

What is deletion?

Answer 12

One or more bases are removed from the sequence of a gene

Question 13

What does insertion and deletion cause?

Answer 13

a frameshift

Question 14

What is a mis-sense mutation?

Answer 14

when substitution causes a different amino acid to be coded for

Question 15

What will happen to the protein as a result of the mis-sense mutation?

Answer 15

• primary structure changes
• may change tertiary structure
• changes overall 3D shape of protein
• functionality of protein likely to change

Question 16

What is a non-sense mutation?

Answer 16

a substitution changes a codon that codes for an amino acid into a stop codon

Question 17

What happens to the protein as a result of the non-sense mutation?

Answer 17

• produced a shorter polypeptide chain
• that is likely to fold differently
• functionality of protein is likely to change

Question 18

What is a silent mutation?

Answer 18

where a substitution occurs that has no effect on the amino acid coded for due to the degenerate nature of the code

Question 19

What happens in a frameshift?

Answer 19

• reading frame will now line up different incorrect triplets after the point of mutation
• significant effect on function of protein

Question 20

End of cellular control A

Answer 20

Start of cellular control b

Question 21

What does the regulatory gene product do?

Answer 21

switches on/off gene

Question 22

What does the structural gene product do?

Answer 22

makes enzymes like beta galactosidase

Question 23

How does RNA polymerase bind to the promoter?

Answer 23

when lactose is present, it binds to the repressor protein
repressor protein changes shape
stops the repressor protein binding to the operator
RNA polymerase can now bind to the promoter
Structural enzymes can now be transcribed

Question 24

What does RNA polymerase bind to when lactose is present?

Answer 24

repressor protein

Question 25

What happens to the repressor protein when RNA polymerase binds to it?

Answer 25

changes shape and cannot bind to the operator

Question 26

What happens now that the repressor protein has changed shape?

Answer 26

RNA polymerase can now bind to the promoter Structural enzymes can now be transcribed

Question 27

What are introns?

Answer 27

non-coding regions inside genes

Question 28

What are exons?

Answer 28

coding regions in genes

Question 29

Where os non-coding DNA found?

Answer 29

within genes and between genes

Question 30

What is splicing?

Answer 30

removing introns to produce mature mRNA mRNA modified

Question 31

What happens when splicing changes?

Answer 31

different versions of mRNA can be produced

Question 32

What does cAMP do?

Answer 32

activates proteins insider the cell by altering 3D structure activates protein kinases

Question 33

What do protein kinases do?

Answer 33

they activate other proteins by phosphorylation

Question 34

End of B

Answer 34

Start of C

Question 35

What is a homebox sequence?

Answer 35

a group of regulatory genes covers a section of DNA for 180 base pairs = 60 Amino acids

Question 36

What is the homeodomain?

Answer 36

proteins made from the homeobox

Question 37

What do homeodomain proteins do?

Answer 37

proteins bind to DNA and switch genes on/off control the body plan

Question 38

What are hox genes?

Answer 38

a group of homeobox genes in animals that are responsible for the position of body parts duplicated over time

Question 39

What does the order/sequence of these genes determine?

Answer 39

head-tail oreintation segments position of limbs position of eyes

Question 40

Why is it ideal to use a fruit fly for studies into the homeobox?

Answer 40

small short life-cycle easy to keep/breed cheap to buy / not rare large cells previously well-studied / many known mutants

Question 41

What can affect homeobox development?

Answer 41

internal factors external factorsq

Question 42

What internal factors effect the homeobox development?

Answer 42

hormones

Question 43

What external factors affect homeobox development?

Answer 43

temperature drugs

Question 44

What is apoptosis triggered by?

Answer 44

transcription factors made by Hox genes breaking down cytoskeleton

Question 45

What does transcription factors made by the hox genes cause?

Answer 45

cytoskeleton to be broken down by lysosomes

Question 46

How do the transcription factors break down the cytoskeleton?

Answer 46

lysosomes / enzymes

Question 47

How are blebs formed?

Answer 47

changes in the cell surface membrane

Question 48

How does the cell break off in segments in apoptosis?

Answer 48

cell breaks off in segments

Question 49

What happens to the segments in apoptosis?

Answer 49

segments are digested phagocyotiss

Question 50

What is an operon?

Answer 50

A cluster of genes under the control of a promoter