2-Gametogenesis

Question 1

first phase of gametogenesis is identical in males and females,

Answer 1

whereas distinct differences exist between the male and female patterns in the last three phases.

Question 2

Chromosomes

Answer 2

Carriers of genetic material

Question 3

35000

Answer 3

On 46 chromosomes

Question 4

Linked genes

Answer 4

Genes on the same chromosomes

Question 5

Autosomes

Answer 5

22 pairs of matching chromosomes

Question 6

One chromosome of each pair is derived from ___1___ and one from the ___2____

Answer 6

1- maternal gamete ( oocyte )

2- paternal gamete ( sperm )

Question 7

Each gamete contain a haploid number of

Answer 7

23 chromosomes

Question 8

Before entering mitosis each chromosome replicates its

Answer 8

DNA

Question 9

Crossover

Answer 9

critical events in meiosis I- interchange of chromatid segments between paired homologous chromosomes

Question 10

Genetic variability is enhanced through

Answer 10

Crossover and through random distribution

Question 11

Numerous ooginia undergo

programmed degeneration

Answer 11

called atresia until menopause

Question 12

Meiosis in Males

Answer 12

Begins after puberty

Question 13

not all spermatogonia enter

Answer 13

meiosis at the same time unlike oogonia

Question 14

When the spermatogonium enter the meiotic phase as primary spermatocyte

Answer 14

they spend several weeks dividing

Question 15

DNA replication in Spermatogonium (type b)

Answer 15

Primary spermatocyte

Question 16

First meiotic division ➡️

Answer 16

2 secondary spermatocytes

Question 17

Second meiotic division ➡️

Answer 17

4 spermatids

Question 18

Spermiogenesis ➡️

Answer 18

4 spermatozoa

haploid gametes

Question 19

meiotic divisions and result in four haploid spermatids takes

Answer 19

64 days

Question 20

acrosome

Answer 20

which covers half of the nuclear surface and contains enzymes to assist in fertilization

Question 21

Maturation of sperms

Answer 21

1- Formation of the acrosome
2- Condensation of the nucleus
3- Formation of the neck, middle piece,
and tail
4- Shedding of most of the cytoplasm as residual bodies

Question 22

Chromosomes fail to separate during meiosis, known as

Answer 22

nondisjunction

Question 23

General term for abnormal number of chromosomes in an embryo is termed

Answer 23

aneuploidy

Question 24

Down Syndrome

Answer 24

Trisomy 21

Question 25

Down syndrome

Symptoms and characteristics

Answer 25

• delayed growth
• distinct facial characteristics
• intellectual disability
• Premature aging
• thyroid dysfunction
• infections

Question 26

The risk of having a child with Down syndrome increases with

Answer 26

maternal age

Question 27

Trisomy 18

Answer 27

• mental retardation
• congenital heart defects
• low set ears
• flex ion of fingers and hands

Question 28

Trisomy 18 Incidence rate

Answer 28

1:5000

usually all die by 2 months of age

Question 29

Trisomy 13

Answer 29

• cleft lip and palate
• eye defects
• deafness
• mental retardation
  Incidence is 1/20,000

More than 90% die in their first month after birth

Question 30

Chromosome 13 in fluorescence

Answer 30

Green

Question 31

Chromosome 21 Fluorescence

Answer 31

Red