Quiz unit 3

Question 1

This is a molecule found in the nucleus that carries the genetic material.

Answer 1

Chromosome

Question 2

The chromosome is made up of ______________ chromatids attached at a point called the ___________.

Answer 2

two identical sister

Centromere

Question 3

The centromere divides the chromosomes into two sections called ________

Answer 3

Arms

Question 4

The shorter arm of the chromosome is referred to as the _________

Answer 4

p arm

Question 5

The longer arm of the chromosome is referred to as the ________

Answer 5

q arm

Question 6

What are the four types of chromosomes based on the location of the centromere?

Answer 6

1. Telocentric chromosome
2. Acrocentric chromosome
3. Submetacentric chromosome
4. Metacentric chromosome

Question 7

It is a type of chromosome where the centromere is located at the tips of the chromosome.

Answer 7

Telocentric chromosome

Question 8

An ___________ has centromeres located quite near the tip of the chromosome.

Answer 8

Acrocentric chromosome

Question 9

____________ have a centromere located near the middle, resulting in a slightly unequal arm.

Answer 9

Submetacentric chromosomes

Question 10

The _____________ has a centrally located centromere with p and q arms of almost the same length.

Answer 10

Metacentric chromosome

Question 11

The compact arrangement of the chromosome is visible only during _____ or ______ of the cell cycle.

Answer 11

cell division or the M-phase (also known as mitosis)

Question 12

During __________, the chromosome is a loosely arranged chromatin.

Answer 12

interphase

Question 13

A single chromosome is made up of a ______ DNA molecule __________ by proteins called _______.

Answer 13

single;
supercoiled;
histones

Question 14

A DNA molecule is made up of _____ DNA strands arranged in an _________ and twisted into a _______

Answer 14

Two;
antiparallel manner;
double helix

Question 15

DNA is made of two strands. Each strand is made up of what three components?

Answer 15

Phosphate Group
Sugar Group
Nitrogenous Bases

Question 16

A sugar and a nitrogenous base form a ________

Answer 16

Nucleoside

Question 17

What is the function of the phosphate groups in DNA synthesis?

Answer 17

Phosphate groups contain high-energy bonds, which bind one nucleoside with an adjacent nucleoside. Forming an entire strand of DNA.

Question 18

In sugar groups, the type of sugar in DNA is called a ________

Answer 18

5-carbon ring of deoxyribose sugar

Question 19

In a nucleotide, the sugar is attached to the phosphate by its __________ carbon .

Answer 19

5’ carbon

Question 20

What is a nitrogenous base?

Answer 20

It is an organic molecule made up of nitrogen

Question 21

How can nitrogen become a base?

Answer 21

Its two lone electrons can act as a base in chemical reactions.

Question 22

What are the two types of nitrogenous bases and their subtypes?

Answer 22

Purines: Adenine and Guanine
Pyrimidines: Cytosine and Thymine

Question 23

Purines and pyrimidines form ____________ attached by what type of bonds?

Answer 23

Complementary base pairs; Hydrogen bonds.

Question 24

Adenine always pairs with ________, forming how many hydrogen bonds?

Answer 24

Thymine; 2 hydrogen bonds

Question 25

Guanine always pairs with_______ forming how many bonds?

Answer 25

Cytosine: 3 hydrogen bonds

Question 26

In the arrangement of the nucleotide in each DNA strand. The _____________ forms the “backbone” of each strand while the ___________ form hydrogen bonds to bind the two strands together and form an entire DNA molecule

Answer 26

Phosphate-sugar combination (or phosphate and sugar groups) nitrogenous bases

Question 27

Group of proteins responsible for DNA packaging

Answer 27

Histones

Question 28

What are the four types of histone proteins?

Answer 28

H2A, H2B, H3, H4

Question 29

In histones, The DNA strand is wound around the ______ during the _______

Answer 29

octamer; initial DNA packaging

Question 30

This protein is responsible for the second level of DNA packaging

Answer 30

Histone 1

Question 31

There are _______ and ______ proteins that are responsible for packaging the DNA so that it would fit into the tiny nucleus and still be functional.

Answer 31

histone and non-histone

Question 32

The first level of packaging is the formation of the ___________

Answer 32

Nucleosome

Question 33

Histones 3 (H3) and histones 4 (H4) proteins allow the 2 nm diameter DNA to wind around the _____ once, forming a ______

Answer 33

Tetramer; Tetrasome

Question 34

A more reliable packaging is achieved if histones ____ and _____ are also present, allowing the DNA to form a negative superhelical (counterclockwise) turn around a histone octamer twice, forming the _____

Answer 34

2A and 2B; Nucleosome

Question 35

A series of nucleosomes form the _______ that looks like “_________”

Answer 35

chromatin; beads on a string

Question 36

What are two models proposed regarding the possible configuration of chromatin?

Answer 36

Zigzag and solenoid

Question 37

The third level of compaction is formed by the interaction between the 30 nm fiber and the nuclear matrix; forming 300 nm radial loops called the ________.

Answer 37

euchromatin

Question 38

The ____________ of the 30 nm fiber anchor to the nuclear matrix via internal matrix proteins, forming what shape?

Answer 38

matrix attachment regions (MARs); loop

Question 39

Although compact, the ______ of the euchromatin still allows _______to access the DNA during the transcription phase of protein synthesis

Answer 39

radial loops; transcription factors

Question 40

Further compaction of the 300 nm euchromatin forms a ____ nm _________

Answer 40

700nm; heterochromatin

Question 41

This level is a tightly compacted chromatin region that prevents transcription factors from accessing the DNA. Thus, no transcription occurs in __________ segments

Answer 41

Heterochromatin

Question 42

There are two types of heterochromatin;

Answer 42

Constitutive and Facultative

Question 43

Permanently inactive heterochromatin - formed by DNA segments that are no longer used or needed by the cell

Answer 43

Constitutive heterochromatin

Question 44

Inactive for some time, then uncoils back to euchromatin if the transcription is required by the cell, then coils again into heterochromatin - formed by DNA segments that are still used or needed by the cell

Answer 44

Facultative Heterochromatin

Question 45

During the ______ stage of cell division, the chromatin enters the last level of compaction

Answer 45

prophase

Question 46

In the prophase stage, all euchromatin coils into heterochromatin, then all heterochromatin undergoes ______ to form the chromosome

Answer 46

Supercoiling

Question 47

Two types of structural maintenance chromosome (SMC) proteins participate in anchoring the chromatin as it forms the chromosome. Which are?

Answer 47

Cohesins and Condensins

Question 48

Shortly before prophase, __________ bind sister chromatids together along their entire length and remain in position until the chromosome is formed.

Answer 48

Cohesins

Question 49

As the cohesins hold on to the sister chromatids, the condensins aid in the _____________ until the final metaphase chromosome is formed

Answer 49

coiling of the chromatin

Question 50

Shortly before _______, the cohesins detach, separating the arms of the chromosome but remains attached in the constricted region called the centromere

Answer 50

metaphase

Question 51

Shortly before ________, cohesins bind sister chromatids together along their entire length and remain in position until the chromosome is formed

Answer 51

prophase

Question 52

State the levels of compaction along with their expected measurements respectively.

Answer 52

1. DNA double-helix (2nm) 2. Nucleosome (11 nm) 3. Chromatin (30nm) 4. Euchromatin (300nm) 5. Heterochromatin (700nm) 6. Chromosome (14000nm)

Question 53

What type of bond connects nitrogenous bases?

Answer 53

Hydrogen bonds

Question 54

What do phosphodiester bonds connect within the DNA structure?

Answer 54

Adjacent sugar groups

Question 55

What do esther bonds connect within the DNA structure?

Answer 55

Phosphate and sugar groups

Question 56

What do N-glycosidic bonds connect within the DNA structure?

Answer 56

Sugar groups and nitrogenous bases.

Question 57

Why are the two strands of DNA anti-parallel to each other?

Answer 57

It allows FAITHFUL REPLICATION. It ensures the production of identical genetic materials.

Question 58

How many human DNA are there?

Answer 58

46 DNAs

Question 59

This term refers to the abundance of Thymine and Adenine nucleic acids.

Answer 59

Tatabox

Question 60

What constitutes Chromatin?

Answer 60

DNA plus Proteins

Question 61

This type of DNA groove allow proteins to bind to and recognize DNA sequences from the outside of the helix.

Answer 61

Major groove

Question 61

Which of the four types of chromosomes (based on centromere position) is not found in humans?

Answer 61

Telocentric Chromosomes.