Brainscape's Knowledge GenomeTM

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


See full index

Bio 189A > Exam 3 Review > Flashcards

Exam 3 Review Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Which event occurs during prophase 1?

A

synapsis and crossing over of homologous chromosomes

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

Before which process do events of interphase ( cell growth and synthesis of DNA) occur?

A

mitosis and meiosis 1

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

If an organism that is homozygous recessive is crossed with an organism heterozygous for that trait, what would most likely be true of the offspring?

A

half would have the dominant phenotype and half would have the recessive phenotype

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

Flower color in snapdragons is an example of incomplete dominance. When a red-flowered plant is crossed with a white flowered plant, the F1 generation will have flowers that are?

A

100% pink

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

Which is true of Meiosis?

A

crossing over occurs
the daughter cells have recombinant DNA
In a 2n=46 cell, the daughters will be n=23
There is half as much DNA in the daughter cells after one division

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

In animals, diploid adults create haploid gametes; diploid zygote

A

Diplontic

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

plants and algae; as an adult, alternates between haploid and diploid; haploid adults use mitosis to make haploid gametes; diploid gametes undergo meiosis to make haploid spores

A

Alternation of Generations

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

In fungi and some protists; haploid adults create haploid gametes; diploid zygote

A

Haplontic

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

The _______ is arrested in _______ of Meiosis 1

A

primary oocyte; prophase

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

If a lady bug cell during the G2 phase of the cell cycle has 200ng of DNA, how much DNA would there be in one of the new cells after mitosis?

A

100ng

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

Before which processes do events of interphase occur?

A

Mitosis and Meiosis 1

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

What is true of two different alleles for a specific gene in a thoroughbread horse?

A

they are different DNA sequences at the same locus on homologous chromosomes

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

What is a true statement regarding the Mendelian exceptions?

A

epistasis can reduce the number of different phenotypes resulting from dihybrid cross

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

A 2n=46 somatic cell has the same number of chromosomes as a gamete in which phase of meiosis?

A

prophase 1
metaphase 1
anaphase 1

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

A 2n=46 somatic cell after interphase has the same amount of DNA as a gamete in which phase of Meiosis?

A

prophase 1
metaphase 1
anaphase 1

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

If there are 20 sister chromatids in a cell, how many chromosomes are there?

A

10

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

If there are 20 chromosomes in a cell at metaphase, how many chromosomes are there in each daughter cell following cytokinesis?

A

20

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

A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. How many picograms would be found at the end of S and the end of G2?

A

16;16

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

During which phase of mitosis do the chromatids become chromosomes?

A

anaphase

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

Telophase

21
Q

A plant-derived protein known as colchicine can be used to poison cells by blocking the formation of the spindle. Which of the following would result if colchicine is added to a sample of cells in G2?

A

The chromosomes would coil and shorten but have no spindle to which to attach.

22
Q

If a eukaryotic cell is in the G1 phase of the cell cycle, which statement about the cell’s chromosomes must be correct?

A

Each chromosome is made of a complex of DNA and associated proteins.

23
Q

Which statement provides the best description of the interphase portion of the cell cycle?

A

During interphase, a cell is metabolically active.

24
Q

What is true of all cancers?

A

They have escaped normal cell cycle controls.

25
Q

What number and types of chromosomes are found in a human somatic cell?

A

44 autosomes and 2 sex chromosomes

26
Q

For what purpose(s) might a karyotype be prepared?

A

for prenatal screening, to determine if a fetus has the correct number of chromosomes
to determine whether a fetus is male or female
to detect the possible presence of chromosomal abnormalities such as deletions, inversions, or translocations

27
Q

How are sister chromatids and homologous chromosomes different from each other?

A

Homologous chromosomes contain the same gene loci but may have different alleles of a particular gene. Sister chromatids are identical copies of each other produced during DNA replication.

28
Q

Which of the following is true of a species that has a chromosome number of 2n = 16?

A

Each cell has eight homologous pairs.

29
Q

How do cells at the completion of meiosis compare with cells that have replicated their DNA and are just about to begin meiosis?

A

They have half the amount of cytoplasm and twice the amount of DNA

30
Q

Chromatids are separated from each other.

A

The statement is true for mitosis and meiosis II.

31
Q

If an organism is diploid and a certain gene found in the organism has 18 known alleles (variants), then any given organism of that species can/must have which of the following?

A

at most, 2 alleles for that gene

32
Q

What takes place in both mitosis and meiosis?

A

separation of sister chromatids

33
Q

In humans, oogenesis in comparison to spermatogenesis is different in that __________.

A

oogenesis does not complete meiosis until after fertilization, but spermatogenesis is complete before the sperm leave the body

34
Q

In vertebrate animals, spermatogenesis and oogenesis differ in that

A

cytokinesis is unequal in oogenesis, whereas it is equal in spermatogenesis.

35
Q

Two plants are crossed, resulting in offspring with a 3:1 ratio of traits for a particular character. What does this suggest?

A

that the parents were both heterozygous for a single trait

36
Q

Consider pea plants with the genotypes GgTt and ggtt . These plants can each produce how many type(s) of gametes?

A

four…. one

37
Q

Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of crosses BbTt × BBtt will be expected to have black fur and long tails?

A

1/2

38
Q

Labrador retrievers are black, brown, or yellow. In a cross of a black female with a brown male, results can be either all black puppies, 1/2 black to 1/2 brown puppies, or 3/4 black to 1/4 yellow puppies. These results indicate which of the following?

A

epistasis is involved

39
Q

Radish flowers may be red, purple, or white. A cross between a red-flowered plant and a white-flowered plant yields all-purple offspring. The part of the radish we eat may be oval or long, with long being the dominant trait.

If true-breeding red long radishes are crossed with true-breeding white oval radishes, the F1 will be expected to be which of the following?

A

purple and long

40
Q

A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Rh positive is a trait that shows simple dominance over Rh negative and is designated by the alleles R and r, respectively. A third gene for the MN blood group has codominant alleles M and N.

Which of the following is a possible partial genotype for the son?

A

IBi

41
Q

Marfan syndrome in humans is caused by an abnormality of the connective tissue protein fibrillin. Patients are usually very tall and thin, with long spindly fingers, curvature of the spine, sometimes weakened arterial walls, and sometimes ocular problems, such as lens dislocation. Which of the following would you conclude about Marfan syndrome from this information?

A

It is pleiotropic

42
Q

A white-eyed female Drosophila is crossed with a red-eyed male Drosophila. Which statement below correctly describes the results?

A

None of the females will have white eyes.

43
Q

Males are more often affected by sex-linked traits than females because

A

males are hemizygous for the X chromosome.

44
Q

In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black female and an orange male?

A

tortoiseshell females; black males

45
Q

White eyes is a sex-linked recessive characteristic in fruit flies. If a female having white eyes is crossed with a wild-type male, what percentage of the F1 males will have white eyes?

A

100%

46
Q

In general, the frequency with which crossing over occurs between two linked genes depends on what?

A

how far apart they are on the chromosome

47
Q

If cell X enters meiosis, and nondisjunction of one chromosome occurs in one of its daughter cells during meiosis II, what will be the result at the completion of meiosis?

A

One-fourth of the gametes descended from cell X will be n + 1, 1/4 will be n - 1, and 1/2 will be n.

48
Q

A couple has a child with Down syndrome. The mother is 39 years old at the time of delivery. Which of the following is the most probable cause of the child’s condition?

A

One member of the couple underwent nondisjunction in gamete production.

Bio 189A (16 decks)

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