Introduction to genetics

Question 1

G1 phase

Answer 1

Growth phase where a cell grows in size and prepares later for DNA replication

Question 2

S-phase

Answer 2

DNA replication occurs

Question 3

G2 phase

Answer 3

Cell preparing proteins like microtubules, needed for cell division during mitosis

Question 4

M-phase

Answer 4

Mitosis

Question 5

G0-phase

Answer 5

Some cells may remain in quiescent, non-dividing stage

Question 6

Structure of DNA

Answer 6

double stranded helix

Question 7

Nitrogenous Bases: 4 types

Answer 7

Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)

Question 8

Bases have specific pairing

Answer 8

A=T, C=G

Question 9

Two strands run in opposite directions, one from ______ and the other from ________

Answer 9

5’ to 3’ , 3’ to 5’

Question 10

DNA replication

Answer 10

• Parent DNA molecule; two complementary strands of base-paired nucleotides
• Parental strands unwind and separate at several points along the DNA molecule, forming replication forks
• Each parental strand provides a template that attracts and binds complementary bases, A with T and G with C
• Sugar-phosphate back-bone of daughter strands closed. Each new DNA molecule consists of one parental and one daughter strand, as a result of semiconservative replication.

Question 11

Cell division

Answer 11

A process by which a cell (parent cell) , divide into two or more cells (daughter cells)

Question 12

Mitosis (produces body cells)

Answer 12

generates 2 identical diploid daughter cells and are capable of dividing

Question 13

Meiosis (produces sex cells)

Answer 13

Generates 4 haploid cells called gametes and cannot divide again until fertilization

Question 14

Diploid

Answer 14

2N , actual number of chromosomes in a cell

Question 15

Haploid

Answer 15

N, half the number of chromosomes in a sperm or egg cell

Question 16

In humans one set of chromosomes

Answer 16

23 pairs / 46 chromosomes

Question 17

how many chromosomes in sperm/egg cell

Answer 17

23 chromosomes

Question 18

Mitosis + cytokinesis

Answer 18

mitotic phase/ M phase

Question 19

WHAT IS cytokinesis

Answer 19

division of nuclei, cytoplasm, organelles & cell membrane

Cytokinesis completion signals the end of the cell division

Question 20

The period of one mitosis to the next is referred to as

Answer 20

interphase

Question 21

4 stages of mitosis

Answer 21

• Prophase
• Metaphase
• Anaphase
• Telophase

Question 22

Prophase

Answer 22

DNA condenses into visible threads

Nuclear envelope disintegrates

Question 23

Metaphase

Answer 23

Chromosomes line up in the middle of the cell

Question 24

Anaphase

Answer 24

Chromosomes (sister chromatids) separate in opposite directions

Question 25

Telophase

Answer 25

Chromosomes restored to less compact, non-mitotic state Nuclear envelope form around daughter nuclei

Question 26

Error in Mitosis

Answer 26

- Error in cell mitosis will activate programmed cell death ( apotosis ) , which will kill the cell - Can lead to cancer or tumour formation

Question 27

meiosis essential

Answer 27

for sexual reproduction

Question 28

Meiosis occurs in 2 stages

Answer 28

Meiosis 1, meiosis 11

Question 29

Meiosis 1

Answer 29

Homologous pairs in a diploid cell separate producing two haploid cells (23 chromosomes)

Question 30

Meiosis 11

Answer 30

By the end of Meiosis 1, sister chromatids are finally split, creating 2 haploid cells per daughter cell (23 chromosomes)

Question 31

End product of meiosis is

Answer 31

4 haploid cells from two haploid cells