Genetic Mutations & Gene Regulation - C5

Question 1

Define degenerate

Answer 1

Multiple bases able to code for an amino acid

Question 2

What does it mean to use DNA?

Answer 2

To make proteins

Question 3

Define Gene

Answer 3

A section of DNA that codes for a protein

Question 4

What is an intron?

Answer 4

Part of a gene that remains in the DNA

Question 5

What is an exon?

Answer 5

Part of a gene that is removed from the DNA and sewn into mRNA

Question 6

What is the purpose of the regulatory gene (at the start of the gene cluster?

Answer 6

Turns ‘on’ all enzymes are made, turns ‘off’ no enzymes are made

Question 7

What are the different kinds of DNA point mutations?

Answer 7

Substitutions, deletions/insertions, inversions

Question 8

What are the two kinds of chromosomal mutations?

Answer 8

Aneuploidy: irregular number of a particular chromosome (Down Syndrome - 3 copies of no. 21 chromosome)
Polyploidy: more than the normal 2 complete sets of chromosomes (wheat has this) caused by issues separating during meiosis

Question 9

Is mutation random?

Answer 9

Yes, but it can be increased by factors such as high energy particles such as UV light, gamma rays, cigarettes, viruses and grilled meat

Question 10

What are mutagens?

Answer 10

Chemical factors - different chemical that reacts with parts of the DNA molecule

Question 11

What are the 3 impacts of mutations?

Answer 11

Neutral - the change does not make a difference (e.g. a point mutation that does not change the amino acid)
Negative - The change alters an amino acid and the protein functions differently (e.g. sickle cell anemia)
Positive - A mutation occurs that does make a difference, but provides genetic advantage (camouflage)

Question 12

What are structural genes?

Answer 12

Genes that produce proteins that become part of structure and function of the organism

Question 13

What are regulator genes?

Answer 13

They determine whether other genes are active or not and the rate at which products are made

Question 14

What is an operon?

Answer 14

A cluster of genes under the control of 1 promoter transcribed as a group - typically code for functionally related proteins (e.g. a group of enzymes all involved in making an amino acid)

Question 15

What do operons contain?

Answer 15

A promoter region, regulatory genes, operator region

Question 16

What is the promoter region?

Answer 16

Short section of DNA where RNA polymerase binds to begin transcription

Question 17

What is the operator?

Answer 17

A section of DNA where a repressor can bind if the enzyme (in this case lacZ, Y and A - for breaking down lactose) is not needed (generally if there is glucose around)

Question 18

What is lacI?

Answer 18

The regulatory gene at the beginning of the operon that codes for the repressor to be made (it also has it’s own promoter)

Question 19

What are the three lac enzymes made in the lac operon?

Answer 19

Lac A, Z and Y

Question 20

What is lactose broken into by the three lac enzymes?

Answer 20

Monosaccharides (single unit sugars for glycolysis)

Question 21

What is the CAP?

Answer 21

Catabolite Activator Protein (positive regulatory site)

Question 22

How is the CAP activated?

Answer 22

by the cAMP (cyclic AMP) which is a ‘hunger signal’ made when glucose levels are low

Question 23

How does cAMP work?

Answer 23

By binding to the CAP, changing its shape and making it able to bind DNA and promote transcription

Question 24

How does the repressor work?

Answer 24

By attaching to the operator and preventing RNA polymerase from making enzymes

Question 25

What is allolactose?

Answer 25

A type of lactose that binds to the repressor when lactose is present, allowing RNA polymerase to pass and make lac enzymes Z, Y and A for lactose digestion

Question 26

What does it mean to be a specialized cell?

Answer 26

In multicellular organisms, cells work together, with each cell having its own specific function

Question 27

What can specialized cells differ in?

Answer 27

Size, shape, number/type of organelles

Question 28

What is an example of a specialized plant and animal cell?

Answer 28

Animal: red blood cells
Plants: Xylem cells

Question 29

How do cells end up different if they all have the same DNA?

Answer 29

Specialization happens during a cells development when exposure to complex biochemicals direct which sections of DNA are used. This is gene regulation

Question 30

Define Totipotent

Answer 30

Can turn into all cell types

Question 31

Define Pluripotent

Answer 31

Can turn into most cell types