Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIO112 > Unit 3 Chapter 12: Meiosis > Flashcards

Unit 3 Chapter 12: Meiosis Flashcards

1
Q

What must happen before sexual reproduction

A

homologs must be reduced by half

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is fertilization

A

when and egg and sperm unite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is meosis

A
  • sexual reproduction
  • a reduction division
  • nuclear division that leads to halving the chromosome number
  • precedes the formation of eggs and sperm in animals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are autosomes

A

chromosomes that are not x/y sex chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are homologous chromosomes (homologs)

A
  • 2 chromosomes of the same type

- carry the same genes but each may have different alleles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a gene

A

a section of DNA that influences some hereditary trait in an individual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a trait

A

a characteristic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is an allele

A

different versions of the same gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does diploid mean

A

2 copies of each chromosome ie. human body cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does haploid mean

A

1 copy of each chromosome ie. human gametes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does the ploidy of meiosis work

A

after meiosis 1: diploid parent cell makes 2 haploid daughter cells (each chromosome is replicated though ie. 2 sister chromatids)
after meiosis 2: 4 haploid cells produced (each chromosome in unreplicated though)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a zygote

A

diploid cell produced from fusion of 2 haploid gametes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is meiosis 1

A
  • begins after chromosomes have been replicated during S phase
  • interphase
  • early prophase 1
  • late prophase 1
  • metaphase 1
  • anaphase 1
  • telophase/cytokinesis 1
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is synapsis

A

-occurs during early prophase 1, homologous chromosome pairs come together forming tetrads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are tetrads

A
  • form from synapsis

- 2 homologous chromosomes which each has 2 sister chromatids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is crossing over

A
  • occurs during late prophase 1
  • when paternal and maternal chromatids break and rejoin at each chiasma (x shaped structure) producing chromatids that have a mix of maternal and paternal segments
17
Q

What happens during early prophase 1

A
  • replicated chromosomes condense
  • spindle forms and nuclear envelope disappears
  • synapsis of homologs forms tetrads
  • kinetochore microtubules attach to kinetochores
18
Q

What happens during late prophase 1

A

-crossing over

19
Q

What happens during metaphase 1

A

tetrads line up at metaphase plate

20
Q

What happens during anaphase 1

A

homologs separate and move to opposite poles

21
Q

What happens in telophase 1

A

homologs finish moving to poles, sometimes nuclear envelope reappears, cell divides

22
Q

What happens during prophase 2

A

-spindle forms (kinetochore microtubules attach to each side of every chromosome-one per sister chromatid)

23
Q

What happens during metaphase 2

A

-replicated chromosomes line up at metaphase plate

24
Q

What happens during anaphase 2

A

-sister chromatids separate, and unreplicated chromosomes move to poles of the cell

25
Q

What happens in telophase 2

A
  • chromosomes finish moving to opposite poles

- nuclear envelope reforms

26
Q

What is the synaptonemal complex

A

a network of proteins that hold 2 pairs of non-sister chromatids together

27
Q

When do most mitotic divisions in plants occur

A

after meiosis 2

28
Q

What is the principle of independent assortment

A

when pairs of homologs line up in meiosis 1 and the separate, a variety of combinations of maternal and paternal chromosomes can result

29
Q

How do you determine how many combinations of maternal and paternal chromosomes are distributed to daughter cells

A

2^n where n=number of chromosomes

30
Q

What is recombination

A

any change in the combination of alleles on a given chromosome
-ie. crossing over produces combination that were not present in either parent

31
Q

What is trisomy

A

3 copies of a chromosome, ie. down syndrome

32
Q

What is nondisjunction

A

if both homologs or sister chromatids move to the same pole of the cell during meiosis

33
Q

What is Klinefelter syndrome

A

XXY in males

34
Q

What is Turner syndrome

A

XO females (missing an x); female and sterile

35
Q

What is a consequence of odd ploidy

A

tend to be sterile as there is are unpaired homologs in metaphase 1

36
Q

Meiosis 2 is similar to which process

A

mitosis in haploid cells

BIO112 (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions