Lab 4

Question 1

What is the five-carbon sugar called in DNA?

Answer 1

deoxyribose

Question 2

Where is the phosphate group attached in DNA

Answer 2

to the 5’ carbon of deoxyribose

Question 3

Where is the nitrogenous base attached?

Answer 3

to the 1’ carbon deoxyribose

Question 4

What are the two types of nucleotide bases?

Answer 4

Purines and Pyrimidines

Question 5

What nitrogenous bases are purines?

Answer 5

adenine and guanine

Question 6

What nitrogenous bases are pyrimidines?

Answer 6

thymine and cytosine

Question 7

What kind of nitrogenous bases are adenine and guanine?

Answer 7

Purines

Question 8

What kind of nitrogenous bases are thymine and cytosine?

Answer 8

Pyrimdines

Question 9

In what direction are DNA strands read?

Answer 9

From 3’ to 5’

Question 10

In what direction are DNA chains synthesized?

Answer 10

From 5’ to 3’

Question 11

In what phase of the cell cycle does DNA replication occur?

Answer 11

The S phase of interphase

Question 12

What is a template?

Answer 12

Two chains of nucleotides that have been unwound for replication

Question 13

Which enzyme separates the DNA strands for replication?

Answer 13

DNA helicase

Question 14

Which enzymes joins complementary base pairs to each template?

Answer 14

DNA polymerase

Question 15

What are Okazaki Fragments?

Answer 15

The short chains that are discontinuously synthesized to the lagging strand.

Question 16

What is the final product of DNA replication?

Answer 16

2 sister chromatids

Question 17

What type of replication is DNA synthesis?

Answer 17

Semi-conservative replication

Question 18

What enzyme “glues” the Okazaki fragments together?

Answer 18

DNA ligase

Question 19

What is Ribosomal RNA?

Answer 19

A structural component of ribosomes

Question 20

What is a triplet code?

Answer 20

Three-base code in DNA

Question 21

What is the start codon?

Answer 21

AUG

Question 22

What is the role of RNA polymerase?

Answer 22

This enzymes binds to the DNA and opens up the helix.

Question 23

What base pairs does the RNA polymerase complex recognize?

Answer 23

A-T base pair regions

Question 24

What are promoter regions?

Answer 24

Areas that are rich in A-T base pairs and where RNA synthesis begins.

Question 25

What direction does the RNA polymerase complex move?

Answer 25

The 3' to 5' direction - opposite to DNA polymerase

Question 26

Where does transcription occur?

Answer 26

In the nucleus

Question 27

When is transcription complete?

Answer 27

When the RNA polymerase complex arrives at a second area rich in A-T base pairs

Question 28

What are introns?

Answer 28

Series of nucleotides that must be removed form RNA before it leaves the nucleus.

Question 29

What is a RNA cap?

Answer 29

3 phosphate groups and a molecule called m^7G that are placed at the 5' end of RNA before it leaves the nucleus

Question 30

What is a polyA tail?

Answer 30

A series of adenine residues that are added to the 3' end of RNA before it leaves the nucleus

Question 31

What is the average size of a gene?

Answer 31

3000 base pairs

Question 32

How many binding sides does a ribosome have for tRNA?

Answer 32

3 binding sites - A,P,E

Question 33

What is the first binding site that tRNA with its amino acid arrives at?

Answer 33

The A site

Question 34

What happens when the tRNA arrives at the E site?

Answer 34

It is released to the cytoplasm and no longer has its amino acid.

Question 35

What happens at the P site of the ribsome?

Answer 35

The amino acid on the tRNA in the A site is joined to the amino acid on the tRNA in the P site.

Question 36

What is point mutation?

Answer 36

A change in a single base on DNA (ex. sickle cell disease.)

Question 37

What is a gene?

Answer 37

A gene is a specific region of a chromosome that is capable of determining the development of a particular trait.

Question 38

What is an allele?

Answer 38

One of several alternate forms of a gene

Question 39

What is phenotype?

Answer 39

The observable characteristics of an organism.

Question 40

What does it mean to be homozygous for a trait?

Answer 40

If you have two identical alleles for that trait.

Question 41

What does it mean to be heterozygous for a trait?

Answer 41

If you have two different alleles for that trait.

Question 42

What is a genotype?

Answer 42

The alleles present in an organism.

Question 43

What is codominance?

Answer 43

Incomplete dominance - a "blend of alleles to from a third phenotype.

Question 44

What is a cross?

Answer 44

When homozyotes for one allele are mated to homozygotes for another allele.

Question 45

What is a P generation?

Answer 45

The individuals initially crossed

Question 46

What is a F1 generation?

Answer 46

First filial - the offspring of the P generation