DNA & Chromosomes

Question 1

deoxyribonucleic acid

Answer 1

DNA

Question 2

Raw material of inheritance and ultimately influences all aspect of the structure and functioning of the human body.

Answer 2

DNA Molecule

Question 3

single molecule of DNA and associated
proteins.

Answer 3

Chromosome

Question 4

located in the nuclei and each human cell contains about 23 different pairs of chromosomes.

Answer 4

Chromosome

Question 5

Composed of repeating units of “nucleotides” which consist of: (3)

Answer 5

Deoxyribose sugar
Phosphate group
One of 4 nitrogen containing bases

Question 6

2 Bases

Answer 6

Purines
Pyrimidines

Question 7

Adenine and Guanine

[bases]

Answer 7

Purines

Question 8

Cytosine and Thymine

[bases]

Answer 8

Pyrimidines

Question 9

backbone - found in the outer structure of the helix.

Answer 9

Sugar and phosphate groups

Question 10

positioned side by side n the inside of the double helix.

Answer 10

Nitrogenous base

Question 11

DNA Synthesis [steps]

Answer 11

1. Initiation
2. Replication
3. Termination

Question 12

Breakage of hydrogen bonds mediated by DNA Helicase and single stranded binding protein (SSB).

[dna synthesis steps]

Answer 12

Initiation

Question 13

Primase generates an RNA primer which initiates replication by binding the DNA Polymerase takes place in both strands but nucleotide can only be added to the 3’ end of an existing strand (leading strand).

[dna synthesis steps]

Answer 13

Replication

Question 14

The 3’ end which consists of non - coding DNA (telomere) is cut off. Enzymes proof-read the sequence (correct pairing) and enzymes called nuclease remove incorrect DNA.

[dna synthesis steps]

Answer 14

Termination

Question 15

Enzymes proof-read the sequence (correct pairing) and enzymes called?

Answer 15

nuclease remove incorrect DNA

Question 16

The nitrogenous bases of DNA are not present in equal proportions and that the proportions of these bases vary from one species to another.

Answer 16

Chargaff’s Rule

Question 17

Consist of a single continuous molecule of DNA complexed with histones and non histone proteins.

Answer 17

Chromatin

Question 18

4 Several levels of DNA organization

Answer 18

1. DNA Helix
2. Histones
3. Solenoid
4. Chromosome

Question 19

Consists of 2 sister chromatids each of which is comprised of contracted and compacted double helix of DNA.

Answer 19

Chromosome Structure

Question 20

more condensed

[chromosome parts]

Answer 20

Heterochromatin

Question 21

silence genes (methylated)

[chromosome parts]

Answer 21

Heterochromatin

Question 22

gene poor (high at content)

[chromosome parts]

Answer 22

Heterochromatin

Question 23

stains darker

[chromosome parts]

Answer 23

Heterochromatin

Question 24

less condensed

[chromosome parts]

Answer 24

Eurochromatin

Question 25

gene expressing [chromosome parts]

Answer 25

Eurochromatin

Question 26

gene rich (higher gc content) [chromosome parts]

Answer 26

Eurochromatin

Question 27

stains lighter [chromosome parts]

Answer 27

Eurochromatin

Question 28

it is the chromosome tips. [chromosome parts]

Answer 28

Tolemeres

Question 29

repeats [chromosome parts]

Answer 29

Tolemeres

Question 30

act as sort of biological clock. [chromosome parts]

Answer 30

Tolemeres

Question 31

being whittled down at each mitosis. [chromosome parts]

Answer 31

Tolemeres

Question 32

it is the middle of chromosomes. [chromosome parts]

Answer 32

Centromeres

Question 33

highly condensed [chromosome parts]

Answer 33

Centromeres

Question 34

also repetitive sequence. [chromosome parts]

Answer 34

Centromeres

Question 35

region where spindle fibers attach. [chromosome parts]

Answer 35

Centromeres

Question 36

pulling chromatids apart during mitosis. [chromosome parts]

Answer 36

Centromeres

Question 37

the smaller of the two arms. [chromosome parts]

Answer 37

P arm

Question 38

the longer of the two arms. [chromosome parts]

Answer 38

Q arm

Question 39

bands are numbered from centromere outward. [chromosome parts]

Answer 39

Q arm

Question 40

4 types of Chromosomes

Answer 40

Telocentric Acrocentric Submetacentric Metacentric

Question 41

no p arm; centromere is on end. [types of chromosome]

Answer 41

Telocentric

Question 42

very small p arm; centromere is very near end. [types of chromosome]

Answer 42

Acrocentric

Question 43

p arm just a little smaller than q arm; centromere in middle. [types of chromosome]

Answer 43

Submetacentric

Question 44

p and q arms are exactly the same length; centromere in exact middle of chromosome. [types of chromosome]

Answer 44

Metacentric

Question 45

These are the sites where the spindle fibers attach.

Answer 45

Kinetochores

Question 46

These two are responsible for the movement of the two sister chromatids to opposite poles of dividing cell during anaphase.

Answer 46

Kinetochores and Spindle apparatus

Question 47

are grouped based on the position of the centromere on the chromosome.

Answer 47

Human chromosome

Question 48

located at the terminal end. [chromosome centromere]

Answer 48

TELOCENTRIC

Question 49

centromere is near one end. [chromosome centromere]

Answer 49

ACROCENTRIC

Question 50

between the middle and end. [chromosome centromere]

Answer 50

SUBMETACENTRIC

Question 51

located at the terminal end. [chromosome centromere]

Answer 51

TELOCENTRIC

Question 52

These are also the site of ribosomal RNA genes and production of RNA.

Answer 52

NORs — Nucleolar Organizer Regions

Question 53

Physical end of chromosome.

Answer 53

Chromosome — Tolemeres

Question 54

Acts as PROTECTIVE CAPS to chromosome ends, preventing end to end fusion of chromosomes and DNA degradation resulting after chromosome breakage.

Answer 54

Chromosome — Tolemeres

Question 55

Plays a role in SYNAPSIS (pairing of 2 homologous chromosomes) during meiosis. Chromosome pairing appears to be initiated in the sub-telomeric regions.

Answer 55

Chromosome — Tolemeres