nucleic acids

Question 1

What are nucleic acids made of?

Answer 1

Nucleotides.

Question 2

What are the components of nucleotides?

Answer 2

• Sugar
• Phosphate group
• Nitrogen-containing base

Question 3

What is a nucleoside?

Answer 3

Sugar and nitrogenous base.

Question 4

What are the nitrogenous bases in nucleic acids?

Answer 4

• Purines: Adenine and Guanine
• Pyrimidines: Thymine and Cytosine

Question 5

What is the sugar component of DNA?

Answer 5

Deoxyribose.

Question 6

What are the nitrogenous bases found in DNA?

Answer 6

• Adenine
• Guanine
• Thymine
• Cytosine

Question 7

What is the sugar component of RNA?

Answer 7

Ribose.

Question 8

What are the nitrogenous bases found in RNA?

Answer 8

• Adenine
• Guanine
• Uracil
• Cytosine

Question 9

Who discovered the structure of DNA?

Answer 9

Watson and Crick (1953).

Question 10

What is the structure of DNA?

Answer 10

• Two strands coiled into a right-handed helix
• Strands are anti-parallel

Question 11

How are the two strands of DNA held together?

Answer 11

Hydrogen bonds between nitrogenous bases.

Question 12

What base pairs with Adenine in DNA?

Answer 12

Thymine.

Question 13

What base pairs with Guanine in DNA?

Answer 13

Cytosine.

Question 14

What is a gene?

Answer 14

A unit of inheritance that carries a characteristic from a parent to a child.

Question 15

What is the genome?

Answer 15

The collective name given to all the genes of an organism.

Question 16

What is a locus?

Answer 16

The position of a gene on a chromosome.

Question 17

What are chromosomes?

Answer 17

Discrete units of the genome carrying many genes.

Question 18

Where is DNA located in prokaryotes?

Answer 18

In the nucleoid.

Question 19

What is a plasmid?

Answer 19

Small, circular DNA molecules.

Question 20

Where is DNA stored in eukaryotes?

Answer 20

In the nucleus.

Question 21

What is chromatin?

Answer 21

DNA packaged with proteins.

Question 22

What are the two types of chromatin?

Answer 22

• Euchromatin: loosely packed, active genes
• Heterochromatin: tightly packed, mostly inactive

Question 23

What is DNA supercoiling?

Answer 23

Over or under winding of a DNA strand.

Question 24

What is a chromatid?

Answer 24

Each copy of a duplicated chromosome.

Question 25

What is the centromere?

Answer 25

Area of condensed chromatin that separates the chromosome into 2 arms.

Question 26

What is a kinetochore?

Answer 26

Large protein assembly that connects chromosomes to microtubules of the mitotic and meiotic spindles.

Question 27

What is a nucleosome?

Answer 27

~147 base pairs of DNA wrapped around histone proteins.

Question 28

What is a chromatosome?

Answer 28

A nucleosome plus one additional histone (H1).

Question 29

What is the diameter of a solenoid?

Answer 29

30nm.

Question 30

What are solenoid loops?

Answer 30

Loops where genes are accessible and regularly expressed.

Question 31

What is heterochromatin?

Answer 31

Compact region of chromatin characterized by reduced transcriptional activity.

Question 32

What are the two types of heterochromatin?

Answer 32

* Facultative: genes expressed early but silenced later * Constitutive: contains permanently silenced genes

Question 33

What is the Histone Code Hypothesis?

Answer 33

Combinations of histone modifications create a 'code' that is read by other proteins.

Question 34

What is acetylation in histone modification?

Answer 34

Changes histone charge from positive to neutral.

Question 35

What role do kinases play in phosphorylation?

Answer 35

Transfer phosphate group from ATP to the target amino-acid.

Question 36

What is methylation in histone modification?

Answer 36

Transfer of methyl group to target lysine and arginine.