Cellular Control + Inheritance

Question 1

What occurs first? Transcription or translation?

Answer 1

Transcription

Question 2

Explain how transcription occurs

Answer 2

Hydrogen bonds are broken between the template + coding strands
Activated RNA nucleotides bond to the template strand
RNA polymerase joins up the molecules
The hydrogen bonds are broken again to release the new RNA strand (mRNA)

Question 3

What is the word used to describe amino acids that have more than 1 possible codes to be synthesised?

Answer 3

Degenerate

Question 4

What do all amino acid chains start with?

Answer 4

Methionine

Question 5

On what type of RNA strand is an anti-codon present?

Answer 5

tRNA

Question 6

What do anti-codons complementory base pair to? And where does this occur?

Answer 6

The codons on an mRNA strand

The Ribsosome

Question 7

What type of reaction occurs to add 2 amino acids together? And what is created?

Answer 7

Condensation

Peptide bond

Question 8

Define point mutations

Answer 8

The change in 1 base due to radiation or mutagens

Question 9

How do point mutations affect proteins?

Answer 9

Change the secondary / tertiary structures

Question 10

Why can substitution mutations be silent?

Answer 10

As the change in base may result in the amino acid being the same as it was before, due to some amino acids being degenerate

Question 11

What type of mutations are frame shift mutations

Answer 11

Insertion

Deletion

Question 12

In the Lac Operon, what happens when lactose is present?

Answer 12

It binds to the repressor protein and causes it to change shape - so it cannot bind to the operator
The RNA polymerase can now transcribe galactosidase and lactose permease
So more lactose is able to enter the cell

Question 13

What does the regulator gene in the Lac Operon do?

Answer 13

Create the repressor protein

Question 14

What are homobox genes arranged into?

Answer 14

Hox Clusters

Question 15

What do homobox genes do?

Answer 15

Control the development of the body plan of an organism

Question 16

Define segmentation gene

Answer 16

The gene that specifies the polarity of each seperate segment

Question 17

Define Maternal-effect gene

Answer 17

The gene that determins the embryos polarity

Eg, which end the head and legs go

Question 18

Define apoptosis

Answer 18

Orderly and programmed cell death

Question 19

Where does crossing over occur in meiosis?

Answer 19

Prophase 1

Question 20

Whenn in meiosis are bivalents formed?

Answer 20

Prophase 1

Question 21

When is meiosis is there are 50:50 chance of each bivalent facing a certain way? Also known as the reassortment of chromosomes

Answer 21

Metaphase 1

Question 22

What is the ratio that is linked with Complemtory Epistasis?

Answer 22

9:7

Question 23

What is the ratio that is linked with Antagonistic Recessive Epistasis?

Answer 23

9:3:4

Question 24

Define Epistasis

Answer 24

The interaction between 2 gene loci, when one gene masks the expression of the other

Question 25

Define Genotype

Answer 25

The genetic make up of an organism in terms of the allelles that it contains

Question 26

Define Phenotype

Answer 26

The expression of the allelles of the genotype that gives the individual observable traits

Question 27

On what type of chromosomes can linkage occur?

Answer 27

Autosomal

Question 28

What does the q in the Hardy Weinburg equation represent?

Answer 28

The recessive allelle