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Flashcards in meiosis Deck (22)
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1
Q

does meiosis produce diploid gametes?

A

no, produces haploid gametes

2
Q

when do male and female haploid gametes fuse?

A

during fertilization - to form a zygote

3
Q

what is the product of meiosis?

A

haploid gametes

4
Q

what is meiosis also referred to as?

A

reproductive and reductive division

5
Q

which stage does recombination take place?

A

prophase I

6
Q

which meiosis stage is most similar to mitosis?

A

meiosis 2

7
Q

what is crossing over?

A

formation of chiasmata, then the small sections of chromosomes can be exchanged between non homologous sister chromatids

8
Q

what is bivalent?

A

pair of homologous chromosomes

9
Q

what allows for greater diversity of genotypes in the population?

A

recombination and independent assortment

10
Q

which stage dominates meiosis?

A

prophase I

11
Q

what happens during meiosis I?

A

maternal and paternal homologues segregate independently and reduce the number of chromosomes to half

12
Q

what happens during meiosis II?

A

sister chromatids seperate and move to opposite oles

13
Q

what is nondisjunction?

A

when the seperation of chromosomes is not normal

14
Q

what does nondisjunction result in?

A

gametes which have either more or less of the usual number of chromosomes - common mechanism of trisomy or monosomy

15
Q

nondisjunction is the cause of several medical conditions in humans including:

A

down syndrome, klinefelter (xxy) syndrome, turner syndorme and XYY syndrome

16
Q

where is spermatogonia found?

A

in the outer cortex of the seminiferous tubules of the testicles

17
Q

is all sperm produced functional?

A

no, sperm are made continously but most are malformed

18
Q

smoking reduces the chances of concieving by …

A

10 to 40%

19
Q

smoking can age a womans body clock by ….

A

10 years

20
Q

how does smoking affect males in terms of fertility?

A

lower sperm count and more malformed sperm than non smokers

21
Q

can genetic defects in sperm affect the children?

A

yes, genetic defects in sperm accumulate and can be carried over into children.

22
Q

do nicotine patches help with fertility?

A

no, the effect on fertility is down to nicotine