Brainscape's Knowledge GenomeTM

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


See full index

exam 3 > ch 13 > Flashcards

ch 13 Flashcards

1
Q

somatic cells

A

humans have 46 chromosomes in somatic cells, which are all cells except the gametes

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

genes

A

coded information in the form of hereditary units

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

gametes

A

reproductive cells that transmit genes from one generation to the next

haploid cells

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

sex chromosomes

A

X and Y chromosomes

exception to the homologous chromosomes.

Females have a pair of X chromosomes
Males have one X and one Y

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

diploid cell

A

a cell with two chromosome sets.

Diploid number is 46 in somatic cells
2n = 46

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

zygote

A

diploid because it has two haploid sets of chromosomes

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

synapsis

A

DNA exchanges between the maternal and paternal sister chromatids (two different non sister chromatids)

the DNA breaks are closed up so that each broken end is joined to the corresponding segment of the non sister chromatid.

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

haploid

A

n = 23
gametes

22 autosomes plus a single sex chromosome. An unfertilized egg has an X chromosome.
A sperm has an X or Y chromosome

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

fertilization

A

union of gametes. restores the diploid condition by combining 2 haploid sets of chromosomes

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

Prophase I

A

centrosome movement, spindle formation and nuclear envelope breakdown. chromosomes condense.

crossing over occurs.

later in prophase I, microtubules will attach to the kinetochores and centromere

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

Metaphase I

A

pairs of homologous chromosomes are arranged at metaphase plate

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

Anaphase I

A

each pair of homologous chromosomes separates.

sister chromatid cohesion persists at centromere, causing chromatids to move as a unit towards the same pole.

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

Telophase I/ Cytokinesis

A

Two haploid daughter cells form. Each chromosome consists of 2 sister chromatids.

one or both chromatids include regions of nonsister chromatid DNA

no chromsome duplication occurs between meiosis I and meiosis II

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

Prophase II

A

spindle apparatus forms. In late prophase II, chromosomes move toward metaphase plate.

no crossing over!

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

Metaphase II

A

chromosomes are at metaphase plate.

two sister chromatids of each chromosome are NOT genetically identical.

the kinetochores of sister chromatids are attached to microtubules extending from poles.

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

Anaphase II

A

breakdown of proteins holding sister chromatids together at the centromere allows chromatids to separate.
individual chromosomes move towards opposite poles.

they are chromosomes, NOT sister chromatids now.

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

Telophase II/ Cytokinesis

A

nuclei form, chromosomes condense.

produces 4 haploid daughter cells containing unduplicated chromosomes.

single strand of UNDUPLICATED DNA

each cell is genetically distinct from another and from parent cell.

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

chiasmata

A

points of crossover.

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

3 events unique to meiosis I

A
  1. synapsis and crossing over occur in prophase I
  2. homologous pairs at metaphase plate during metaphase I. There individual chromosomes during mitosis and meiosis II
  3. Separation of homologs. anaphase I, sister chromatids of each chromosome stay attached. in mitosis, the sister chromatids separate.
20
Q

independent assortment of chromosomes

A

maternal/paternal chromosomes can line up in any orientation

this occurs during meiosis I metaphase alignment

21
Q

recombinant chromosomes

A

individual chromosomes that carry genes (DNA) derived from two different parents

occurs because of crossing over.

22
Q

crossing over

A

recombinant chromosomes create new combinations of genetic traits

23
Q

random fertilization

A

adds to genetic variation arising from meiosis.

mate selection and gamete fertilization- each person is truly unique!

24
Q

a human cell containing 22 autosomes and a Y chromosome is?

A

a sperm

25
Q

meiosis II is similar to mitosis in that

A

sister chromatids separate during anaphase

26
Q

If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be

A

2x

27
Q

karyotype

A

chromosomes are arranged in pairs; ordered display

28
Q

If we continued to follow the cell lineage from question 4, then the DNA content of a single cell at metaphase of meiosis II would be

A

x

29
Q

A diploid cell contains 10 chromosomes (2n = 10). If the cell undergoes meiosis, how many chromosomes and chromatids will be present in each daughter cell afer telophase I

A

5 chromsomes, 10 chromatids

30
Q

Where does crossing over occur?

A

Crossing over occurs between homologous chromosomes (they are related)

Chiasmata indicates a crossover has occurred.

31
Q

autosome

A

any chromosome that is not a sex chromosome.

32
Q

locus

A

genes specific location along the length of a chromosome

33
Q

Meiosis I

A

goes from diploid to haploid. each chromosome still has 2 sister chromatids
one cell creates 2 daughter cells

34
Q

Meiosis II

A

haploid to haploid. creates 4 daughter cells

each cell makes 2 new cells

35
Q

n

A

number of chromosomes in a single set

36
Q

what is biggest difference between meiosis and mitosis?

A

Metaphase I

37
Q

Differences between Mitosis and Meiosis

A
  1. mitosis occurs in diploid and haploid. Meiosis only occurs in diploid cells.
  2. number of divisions. mitosis has one division. meiosis has 2 divisions.
  3. Synapsis does not occur in mitosis.
  4. mitosis creates 2 identical daughter cells. meiosis creates 4 genetically different haploid cells
  5. Mitosis has 5 phases and meiosis has 4 phases
  6. mitosis is somatic cells and meiosis is reproductive cells.
38
Q

Similarities between Mitosis and Meiosis

A
  1. DNA replication occurs during interphase

2. both have cytokinesis

39
Q

what are separated during meiosis I?

A

homologous pairs of chromosomes

40
Q

what are separated during meiosis II?

A

sister chromatids

41
Q

Mitosis is most similar to ____________ in terms of chromosomal separation.

A

meiosis II

42
Q

If a cell only has two chromosomes and a non-disjunction event occurs during Meiosis I, what would the resulting gametes look like with regard to chromosome content?

A

gametes with abnormal chromosome number can arise by nondisjunction in either meiosis I or meiosis II; can also happen during mitosis.

Nondisjunction can also happen in meiosis II, with sister chromatids (instead of homologous chromosomes)

43
Q

What type of cells are produced following Meiosis I?

A

two haploid cells, each with distinct genetic material

44
Q

One major feature of meiosis is the genetic variability that is generated. Which two mechanisms do you think would generate the most variability together?

A

random fertilization and independent assortment

45
Q

For your birthday, you received a purple flowering pea plant. However, the friend that gave it to you did not know its genotype. You know you can figure it out by crossing it to a homozygous recessive white flowering (pp) pea plant. After performing the cross, you end up with all of the offspring having purple flowers. What is the genotype of the plant you received for your birthday?

A

PP

46
Q

If a male fly with white eyes is crossed to a female fly with red eyes, is it possible to observe female offspring with white eyes?

A

Yes

47
Q

During meiosis chromosomes compact for what reason?

A

to allow their movement without breaking

exam 3 (7 decks)

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