Meiosis

Question 1

Meiosis doesn’t take place in all eukaryotes. True or false?

Answer 1

False - it is important for sexual reproduction and takes place in all eukaryotes

Question 2

Does meiosis produce haploid or diploid gametes?

Answer 2

Haploid

Question 3

Why do male and female gametes need to fuse during fertilisation?

Answer 3

As meiosis produces haploid gametes, they need to fuse to create a new diploid cell known as a zygote

Question 4

Meiosis is known as reproductive or ______ division

Answer 4

reductive

Question 5

diploid cells (2n) produce ____ (n) gametes

Answer 5

4 haploid

Question 6

what must happen to the DNA before meiosis can begin?

Answer 6

DNA must be replicated (just like in mitosis)

Question 7

At what stage of meiosis does recombination take place?

Answer 7

Prophase 1

Question 8

Meiosis 2 involves separation of __________

Answer 8

sister chromatids

Question 9

Crossing over (during recombination) requires close alignment of homologous pairs of chromosomes known as _______

Answer 9

bivalents

Question 10

What is the name given to the junctions that are formed as a result of crossing over?

Answer 10

Chiasmata

Question 11

Chiasmata allows small sections of chromosomes to be exchanged between ___________ sister chromatids

Answer 11

non-homologous

Question 12

What is the significance of meiosis?

Answer 12

facilitates sexual reproduction
genetic variability in gametes
recombination and independent assortment allow for a greater diversity of genotypes in the population

Question 13

Which stage of meiosis dominates?

Answer 13

Prophase 1

Question 14

Sister chromatids separate during meiosis 1. True or false?

Answer 14

False - they separate during meiosis 2

Question 15

What does disjunction mean?

Answer 15

The normal separation of chromosomes

Question 16

If separation of chromosomes is not normal, it’s called _________

Answer 16

nondisjunction

Question 17

What does Klinefelter Syndrome result in?

Answer 17

An extra X chromosome in males

Question 18

What does Turner Syndrome result in?

Answer 18

Only one X chromosome in females

Question 19

Who does the XYY Syndrome affect?

Answer 19

males

Question 20

Gamete production in females is called _______

Answer 20

oogenesis

Question 21

In females, meiosis occurs in precursor cells known as _______ that divide twice to produce the ________

Answer 21

oogenia

oocytes

Question 22

Oocytes stop at an early stage of meiosis 2 and lay dormant within the ovaries inside a layer of somatic cells called the follicle. True or false?

Answer 22

False - early stage of meiosis 1

Question 23

During the menstrual cycle in females, follicles produce mature _________ which continue meiosis 1 and arrest at meiosis 2 until fertilisation or menstruation

Answer 23

oocytes

Question 24

What is gamete production in males called?

Answer 24

Spermatogenesis

Question 25

In males, meiosis occurs in stem cells known as ________

Answer 25

spermatogonia

Question 26

Spermatogonia divide twice to become __________

Answer 26

spermatozoa

Question 27

Where are the spermatogonia found?

Answer 27

outer cortex of the seminiferous tubules of the testicles

Question 28

Sperm are made continuously but most are malformed. True or false?

Answer 28

True

Question 29

For successful fertilisation, the ejaculate must contain at least _____ normal sperm

Answer 29

15%

Question 30

Smoking reduces the chances of conceiving by _____

Answer 30

10-40%

Question 31

Smoking can age a woman's body clock by 10 years. True or false?

Answer 31

True

Question 32

Men who smoke have lower sperm counts and more malformed sperm than non-smokers. True or false?

Answer 32

True

Question 33

Genetic defects in sperm can accumulate but cannot be passed on to children. True or false?

Answer 33

False - they can be passed on

Question 34

Effect on fertility is down to nicotine so nicotine patches reduce the chances of these problems happening. True or false?

Answer 34

False - nicotine patches can cause similar problems