General Genetics

Question 1

Chromosomes carry genes responsible for______

Answer 1

Hereditary characters

Question 2

Each somatic cell contains _______ chromosome (_____pairs)

Answer 2

46
23

Question 3

The normal number of chromosome in somatic cells are called _____ or _____

Answer 3

Euploidy
Diploidy

Question 4

What we call chromosomes responsible for somatic characteristics

Answer 4

22 pairs of autosomes

Question 5

What we call chromosomes responsible for sex characteristics

Answer 5

One pair of sex chromosomes

Question 6

What are homologous chromosomes?

Answer 6

Each pair of chromosomes (every 2 chromosomes ) contain one chromosome originally derived from the mother and the other is derived from the father .

Question 7

Example for cells containing a haploid number of chromosomes

Answer 7

Sperms and ova
Germ cells

Question 8

What we call the 2 chromatids ?

Answer 8

2 S-chromosomes

Question 9

Chromosomes terminate at one end called

Answer 9

Telomere

Question 10

Which structure carry specific genes in the chromosome

Answer 10

Chromited

Question 11

Serves as a site for attachment of spindle

Answer 11

Kinetochore

Question 12

What is the site and function of telomere

Answer 12

Site: at the tip of chromosome

Function: protect and stabilize chromosome ends .
Responsible for cell division limitation

Question 13

the centromere is present central in position( Midway between the two end)

Answer 13

Metacentric

Question 14

The centromere is present between the center of the chromatin and their upper ends

Answer 14

Submetacentric

Question 15

Centromere is present very near to the terminal ends.

Answer 15

Acrocentric

Question 16

Centromere is present at the terminal ends of chromatids.

Answer 16

Telocentric

Question 17

Name proteins that activate (phosphrylate) enzymes and other proteins needed for phase-specific function

Answer 17

Cyclins and cyclin-dependent kinases CDKs

Question 18

D-chromosome contains

Answer 18

2 sister chromatid

Question 19

The purpose of the cell cycle is to _______

Answer 19

Produce two daughter cells, each containing chromosomes identical to those of parental cells

Question 20

The cell cycle is critical because

Answer 20

The genetic instruction for cellular characteristics are passed from parent to daughter cells

Question 21

What is checkpoint in the cell cycle?

Answer 21

Progression(development ) through the cell cycle is regulated at points called checkpoints

Question 22

A phase representing the growth of the cell is called

Answer 22

Interphase

Question 23

The phase in which cell division occurs is called

Answer 23

Mitosis

Question 24

Chromosomes in the interphase are not visible but chromatids threads are visible

Answer 24

True

Question 25

Defects in checkpoints can lead to cancer

Answer 25

True

Question 26

What occur in G1 phase ?

Answer 26

Activate RNA and protein synthesis

#The cell grow to parents size
#The cell contain 46 S-chromosomes or single-threaded chromosome or one chromatid

Question 27

G1/S checkpoint

Answer 27

Cell size
Nutrients
Growth factor
DNA damage

Question 28

What phase differentiated cell take

Answer 28

G0

Question 29

Example for terminally( نهائيا ) differentiated cells

Answer 29

Most muscles cells
Nerve cells

Question 30

Name differentiated cells that can return to the G1 phase

Answer 30

Liver cells

Question 31

In the S phase, what do we call the chromosome? And what does it compose of?

Answer 31

46 double-threaded D-chromosome and it compose of 2 sister chromatids

Question 32

G2 phase

Answer 32

Biochemical events and proteins synthesis necessary for cell division
Ensures that only healthy DNA can pass through this checkpoint

Question 33

When centrioles duplicate

Answer 33

In the S phase

Question 34

What is the longest phase of mitosis

Answer 34

Prophase

Question 35

Centrosome formed of

Answer 35

One pair of centrioles

Question 36

Name the changes that occur in prophase

Answer 36

nucleus disintegrate

# chromosomes appears as condensed double thread (d-chromosomes)
# the 2 centrosomes with their 2 centrioles migrate toward the opposite poles of the cell
# release of mitotic spindle with Astral, polar , kinetochore microtubules
#اجتهاد من عندي
Lamins and nuclear membrane are phosphorylated

Question 37

Name what occure in Metaphase

Answer 37

Further condensation of chromosomes occur

#cell is spherical in shape
#D-chromosomes form metaphase plate
#each chromosomes( Specifically, the Centrosome) is attached to the spindle fibers kinetochore microtubules .
إضافة mcq مهمة
#Spindle assembly checkpoint each chromosomes is aligned properly in metaphase plate

Question 38

Name what occur Anaphase

Answer 38

it’s the shorts stage of mitosis

# separation of sister chromosomes (disjunction)occurs
# motor protein contribute to chromosomes movement by generating forces that pull chromosomes toward the spindle poles
# sister chromatids will move to opposite poles due to the shortening of kinetochore
# the two poles move apart ( بعيدا) inresponse to the elongation of poles microtubules
# each chromatid now is an individual chromosomes (s-chromosomes)

Question 39

What is mitosis?

Answer 39

It’s a type of cell division ( remember meiosis) characterized by appearance of threads of chromosomes
Mitosis=thread

Question 40

How long mitosis take ?

Answer 40

1 -1.5 hours

Question 41

The number of chromosomes increase only in _______ & go back to its normal in_____

Answer 41

Anaphase
Cytokinesis

Question 42

What we count to decide the number of chromosomes?

Answer 42

Centromeres

Question 43

How we count DNA?

Answer 43

If sister chromatids are present , so chromosomes have replicated
So the number of DNA are doubled

Question 44

The number of DNA increase in ______& decrease in_____

Answer 44

S phase (2n)
Cytokinesis (1n)