Unit 3 Exam Review

Question 1

What are nucleotides?

Answer 1

the repeating units of nucleic acids(sugar group, phosphate group and nitrogenous base)

Question 2

What are the purines?

Answer 2

Adenine and Guanine

Question 3

What are the pyrimidines?

Answer 3

Cytosine and Thymine (And Uracil in RNA only)

Question 4

What are histones

Answer 4

a member of the family of proteins that associate with DNA in eukaryotic cells that acts to help compact the DNA

Question 5

What is a nucleosome?

Answer 5

condenced structure foremed when double-stranded DNA wraps around an octamer of histone proteins

Question 6

What is a chromatin?

Answer 6

the non-condenced form of genetic material that predominates for most of the eukaryotic cell cycle

Question 7

What is DNA replication?

Answer 7

The process of producing two identical DNA molecules from an original, parent DNA molecule

Question 8

What are the 3 phases of DNA replication

Answer 8

initiation, elongation and termination

Question 9

What is helicase?

Answer 9

a group of enzymes that aid in the unwinding of DNA

Question 10

What is DNA polymerase III

Answer 10

an enzyme that adds nucleotides to the 3’ end of a growing polynucleotide strand

Question 11

What is DNA polymerase I?

Answer 11

enzyme that removes RNA primer and fills gaps between okazaki fragements on the lagging strand with DNA nucleotides

Question 12

What is DNA ligase?

Answer 12

enzyme that catalyzes the joining of Okazaki fragements

Question 13

What is DNA polymerase II

Answer 13

enzyme that proofreads newly synthesized DNA

Question 14

What is mRNA?

Answer 14

RNA that contains the genetic information of a gene and carries it to the protein synthesis machinery

Question 15

What is the DNA replication fork?

Answer 15

The point at which the two strands of DNA are separated to allow replication of each strand

Question 16

What is transcription?

Answer 16

the synthesis of RNA from a DNA template

Question 17

What is transcription?

Answer 17

synthesis of protein from an mRNA template

Question 18

What is RNA polymerase?

Answer 18

Main enzyme that catalyzes the formation of RNA from a DNA Template

Question 19

What is pre-mRNA?

Answer 19

mRNA that has not undergone processing

Question 20

What is mature mRNA?

Answer 20

mRNA that has undergone processing

Question 21

Whst is a start codon?

Answer 21

A triple of 3 bases that specifies the first amino acid of a protein

Question 22

What is a peptide bond?

Answer 22

a covalent bond formed between 2 amino acids during protein synthesis

Question 23

What is mutation?

Answer 23

permenant change in the nucleotide squence of a cell’s DNA

Question 24

What is single-gene mutation?

Answer 24

mutation that involved changes in the squence of one gene

Question 25

What is chromosome mutation?

Answer 25

Mutation that involves changes in chromosomes and may involve many genes

Question 26

What is point mutation?

Answer 26

Mutation involving a single base pair substitution, insertion or deletion

Question 27

What is frameshift mutaion?

Answer 27

Mutation caused by the addition/deletion of a number of nucleotides not divisible by three resulting in a chnage in the frameshift

Question 28

What is silent mutation?

Answer 28

Mutation that does not change the amino acid sequence of a protein

Question 29

What is missense mutation?

Answer 29

Mutation that changes the amino acid sequence of a protein

Question 30

What is nonsense mutation?

Answer 30

mutation that shortens a protein by introducing a stop codon

Question 31

What is restriction endonuclease?

Answer 31

Enzyme that cuts the inside of double-stranded DNA in a sequence-specific manner

Question 32

What is DNA finger printing?

Answer 32

technology used to identify individuals by analyzing the DNA sequence of certain regions of their genome

Question 33

What is PCR?

Answer 33

automated method for amplyfying sprecific regions of DNA from extremely small quantities