Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Bio 1 > Ch.13 (Meiosis) > Flashcards

Ch.13 (Meiosis) Flashcards

1
Q

What are the advantages of sexual reproduction? (2)

A

Increases genetic variability of offspring.
Increases potential of survival of population in changing environment.

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

Homologous chromosomes : traits (6)

A

one copy from mother, one from father
same length and shape
same bonding (staining) patterns
same genes and same order of genes
similar but not identical DNA sequences
karyotype

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

Karyotype [definition]

A

display of. metaphase chromosomes showing their bonding patterns, numbers and the ploidy

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

What is the human diploid number?

A

46

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

Diploid [equation]

A

2n = number

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

In humans, how are pairs separated? (number of normal pairs, somatic pairs and sex pair)

A

22 somatic pairs (autosomes)
1 pair sex

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

Pattern for females (2)

A

XX
ovum always carries 22 + X

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

Pattern for males (2)

A

XY
sperm carries 22 + Y

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

locus [definition]

A

Position of a gene on a molecule.

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

What three events does human sexual reproduction go through?

A

Meiosis (gametes form)
Fertilization (sperm and egg unite to form zygote)
Mitosis + dev. (multicellular organism created from zygote)

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

Haploid [equation]

A

n = number

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

What does meiosis do to the number of chromosomes for gametes?

A

Divides the number of chromosomes by HALF for coming gamete.

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

Gametes formed are: diploid or haploid?

A

Haploid (n)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens to the number of chromosomes in fertilization?

A

Restores diploid number (2n)

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

What does meiosis consists of? (2)

A

2 nuclear divisions:
Meiosis 1
Meiosis 2

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

How many does DNA replication occur in meiosis, and where?

A

Occurs once, in S of interphase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

DNA replication in S - what happens to the homologous chromosomes?

A

They pair up = synapsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Meiosis 1 - what happens? (3)

A

of chromo reduces by HALF

homologous chromo. separate
2 daughter cells form
number of chromosomes reduce by HALF (2nā€“>n)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Meiosis 2 - what happens? (2)

A

sister chromatids separate with no prior DNA replication
4 daughter cells called GAMETES form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Phases of Meiosis 1 (4)

A

Prophase 1
Metaphase 1
Anaphase 1
Telophase 1

21
Q

Phases of Meiosis 2 (4)

A

Prophase II
Metaphase II
Anaphase II
Telophase II

22
Q

Prophase I -what happens?

A

chromsomes condense
synapsis
crossing over

23
Q

Synapsis [definition]

A

homologous chromosomes pair up through synapotnemal complex (glue)

24
Q

Crossing over [defintion]

A

homologous chromosomes exchange segments

25
Metaphase I
alignment of tetrads along equator independent assortment : homologous pairs align
26
What are homologous chromosomes held by in Metaphase 1?
Chiasmata
27
Anaphase 1
separation of homologous chromosomes but NOT sister chromatids
28
Telophase 1 (2)
chromosomes decondense
29
Prophase II
chromosomes recondense NO DNA SYNTHESIS
30
Are the resulting nuclei from telophase 1 haploid or diploid?
Haploid (n)
31
Metaphase II
chromosomes align at equator
32
Anaphase II
Sister chromatids separate
33
Are sister chromatids still considered sister chromatids in anaphase II? Why?
No, because of crossing over.
34
Telophase II (2)
Chromsomes decondense Cytokinesis occurs
35
What kind of cells (haploid or diploid) does telophase II form? And how many?
4 DIFFERENT haploid cells
36
How many haploid nuclei reform in telophase II?
4
37
What is variation due to? (2, one with a b c)
1.Production of unique gametes by meiosis : a. homologous but not identical b. crossing over Prophase I c. independent assortment Metaphase I 2. Random fusion of egg and sperm
38
Crossing over [definition]
Each pair of chromosomes exchange segments.
39
Independent assortment [definition]
meiosis assigns one of every pair of chromosomes to a gamete RANDOMLY
40
Which is similar to mitosis: meiosis 1 or 2?
Meiosis 2
41
How many chromosomes and chromatids in G1 (meiosis)?
2 chromosomes 0 chromatids
42
How many chromosomes and chromatids in Prophase I?
2 chromosomes 4 chromatids
43
How many chromosomes and chromatids in Prophase II?
1 chromosome 2 chromatids
44
How many chromosomes and chromatids in a single gamete?
1 chromosome 0 chromatids
45
For humans, how many chromosomes and chromatids in G1 meiosis?
46 chromosomes 0 chromatids
46
For humans, how many chromosomes and chromatids in prophase I?
46 chromosomes 92 chromatids
47
For humans, how many chromosomes and chromatids in prophase II?
23 chromosomes 46 chromatids
48
For humans, how many chromosomes and chromatids in gametes?
23 chromsomes 0 chromatids

Bio 1 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions