Final Exam -- Last Chapter things

Question 1

Missense mutations occur when ____.

Answer 1

The mutation causes a single amino acid to change

Question 2

The random addition, deletion, or substitution of a nucleotide in the sequence of a gene is called a ___.

Answer 2

mutation

Question 3

T/F: It is possible for a mutation to have no effect on the organism

Answer 3

True

Question 4

T/F: If a mutation occurs in the promoter sequence of a gene that actual gene product will not change but the rate of transcription of the gene may change.

Answer 4

True

Question 5

What is a thymine dimer?

Answer 5

Bonding of 2 adjacent thymine nucleotides

Question 6

Nucleotide excision repair occurs when:

Answer 6

Segments of DNA containing mutations are removed

Question 7

T/F: DNA repair systems are composed of proteins that detect irregularities in DNA structure and then fix the abnormality to prevent mutation.

Answer 7

True

Question 8

What is the function of the UvrA-UvrB complex?

Answer 8

Scanning the DNA for mutations

Question 9

What happens in interphase?

Answer 9

Chromosomes have already replicated during interphase

Question 10

What happens in prophase?

Answer 10

• Sister chromatids condense
• The mitotic spindle starts to form
• Nuclear envelope begins to dissociate into vesicles
• Nucleolus is no longer visible

Question 11

What happens in prometaphase?

Answer 11

• Nuclear envelope has completely dissociated into vesicles
• The mitotic spindle is fully formed
• Sister chromatids attach to the spindle via kinetochore microtubules
• Centrosomes move apart and demarcate the two poles
• Spindle fibers interact with sister chromatids

Question 12

what happens in cytokinesis?

Answer 12

• Division into two daughter cells (end of mitosis)

Question 13

What happens in metaphase?

Answer 13

• Pairs of sister chromatids are aligned along a plane halfway between the poles (metaphase plate)
• Organized into a single row

Question 14

What happens in anaphase?

Answer 14

• connection broken between sister chromatids
• each individual chromatid is linked to only one pole by kinetochore microtubles
• kinetochore microtubules shorten, pulling chromosomes toward the pole to which they are attached
• two poles

Question 15

What happens in telophase?

Answer 15

• Chromosomes have reached their respective poles and decondense
• Nuclear membranes now re-form to produce two separate nuclei

Question 16

What is a nonsense mutation?

Answer 16

A mutation that inserts a STOP codon

Question 17

What is a missense mutation?

Answer 17

A mutation that changes the amino acid

Question 18

What is a frameshift mutation?

Answer 18

• insertion: insert of a nucleotide

- deletion: removal of a nucleotide

Question 19

Mendellian ratio?

Answer 19

3:1

Question 20

Dihybrid 2 factor ratio?

Answer 20

9:3:3:1