BIO 111 (General Biology) Chapter 10 (Campbell; Mastering Biology)
In a diploid set of chromosomes, one member of each pair of homologous chromosomes is derived from the father (paternal) and the other comes from the mother (maternal). If 2n = 6, what is the probability of obtaining a gamete in which all the chromosomes are paternal ones?
1/8
If the DNA content of a diploid cell in the G 1 phase of the cell cycle is 24 fg (femtograms), then the DNA content of the same cell at metaphase of meiosis I would be
12 fg
How many different combinations of maternal and paternal chromosomes can be packaged in gametes made by an organism with a diploid number of 8 (2n = 8)?
16
A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes.
16; which is half of 32
If a sexually reproducing organism has a diploid number of 36, how many individual chromosomes would any of its gametes have?
18 chromosomes
In human gamete production there is an average of _____ crossover events per chromosome pair.
2-3
How many pairs of autosomes do humans have?
22
Scientists have produced a hybrid plant that was the result of the fertilization of gametes between one plant with a diploid number of 24 and another with a diploid number of 20. How many chromosomes would the diploid hybrid plant have?
22 chromosomes
Normal human gametes carry _____ chromosomes.
23
If the DNA content of a diploid cell in the G1 phase of the cell cycle is represented by x, then the DNA content of the same cell at metaphase of meiosis I would be __________.
2x
The following question refers to the essential steps in meiosis described below.1. formation of four new nuclei, each with half the chromosomes present in the parental nucleus2. alignment of homologous chromosomes at the metaphase plate3. separation of sister chromatids4. separation of the homologs; no uncoupling of the centromere5. synapsis; chromosomes moving to the middle of the cell in pairs. Which of the steps take(s) place in both mitosis and meiosis?
3
In a male mammal, every germ cell that undergoes meiosis in the production of gametes gives rise to __________ sperm.
4
The egg (ovum) of a rabbit contains 22 chromosomes. How many chromosomes are in the somatic (body) cells of a rabbit?
44
What number and types of chromosomes are found in a human somatic cell?
44 autosomes and 2 sex chromosomes
If the DNA content of a diploid cell in the G 1 phase of the cell cycle is 24 fg (femtograms), then the DNA content of the same cell at metaphase of meiosis II would be
48 fg
In a diploid cell containing 10 chromosomes, meiosis results in the formation of daughter cells containing __________ chromosomes.
5
Which of the following statements correctly describes an organism's genome?
A genome is a complete set of all of an organism's genes.
Why are cells arrested at metaphase in the preparation of a karyotype?
All of their chromosomes are highly condensed and easy to visualize.
Which of the following is included in alternation of generations?
All; Multicellular haploid stage (gametophyte), Spores, Multicellular diploid stage (sporophyte), Zygote
Which of the following statements best describes the advantage that sexual reproduction likely provides over asexual reproduction?
Although energetically more costly than asexual reproduction, sexual reproduction leads to different combinations of alleles that could provide adaptability in a changing environment.
Which of the following statements correctly describes the characteristics of recombinant chromosomes?
At least one to three times per chromosome pair, they carry genes from two different parents.
Which of these gametes contains one or more recombinant chromosomes?
B and C
Which of these gametes contain one or more recombinant chromosomes?
B, C, F, and G
Two sister chromatids are joined at the centromere prior to meiosis. Which statement is correct?
Barring mutation, the two sister chromatids must be identical.
Which of these cells is (are) haploid?
C and D
If a horticulturist breeding plants known as gardenias succeeds in having a single plant with a particularly desirable set of traits, which of the following processes would be her most probable and efficient route to establishing a line of such plants with that particular set of traits?
Clone the plant asexually to produce an identical one.
Which of the following is true of an organism that has a chromosome number of 2 n = 16?
Each cell has eight homologous pairs of chromosomes.
Which of the following is true of an organism that has a chromosome number of 2n = 16?
Each cell has eight homologous pairs of chromosomes.
A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure above. A female with a paternal set of one orange and one long gene chromosome and a maternal set composed of one blue and one short gene chromosome is expected to produce which of the following types of eggs after meiosis?
Each egg has a one-fourth chance of having blue long, blue short, orange long, or orange short combinations.
The somatic cells of a type of shrub called a privet each contain 46 chromosomes. To be as different as they are from human cells, which have the same number of chromosomes, which of the following must be true?
Genes of privet chromosomes are significantly different from those in humans.
How are sister chromatids and homologous chromosomes different from each other?
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.
Refer to the life cycles illustrated in the figure above. Which of the life cycles is (are) typical for animals?
I only
You have isolated DNA from three different cell types of an organism, determined the relative DNA content for each type, and plotted the results on the graph shown in the figure above. Which sample(s) of DNA might be from a germ cell arrested in prophase I of meiosis?
II
Refer to the life cycles illustrated in the figure above. Which of the life cycles is (are) typical for plants and some algae?
II only
You have isolated DNA from three different cell types of an organism, determined the relative DNA content for each type, and plotted the results on the graph shown in the figure above. Which sample(s) of DNA might be from a cell at the end of anaphase II of meiosis?
III
Which of the following statements correctly describes the differences between sexual and asexual reproduction?
In sexual reproduction, offspring vary genetically from their siblings and both parents.
Which of the following contributes to genetic variation in sexually reproducing species?
Independent assortment, crossing over, and random fertilization
If a cell has completed the first meiotic division and is just beginning meiosis II, which of the following statements describes the genetic or chromosomal contents of this cell?
It has half the amount of DNA of the cell that began meiosis.
A given organism has 46 chromosomes in its karyotype. Which of the following statements is correct regarding this organism?
Its gametes must have 23 chromosomes.
Which of the following human cells contain 46 chromosomes?
Liver cells
Predict allele combinations in the cells resulting from this meiotic event. (It will help if you draw out the rest of meiosis and label the alleles by name.)
Two cells will be obtained after meiosis I. The first cell will bear "freckles" and "black hair" + "no freckles" and "black hair" alleles and the second will bear "no freckles" and "blond hair" + "freckles" and "blond hair" alleles.
If chiasmata can be seen in a cell under a microscope, which of the following meiotic processes must have occurred?
Prophase I
Synapsis occurs during _____.
Prophase I
Synapsis occurs during __________.
Prophase I
Which of the following statements regarding sexual life cycles is correct?
Sexual life cycles can produce both haploid and diploid cells at different stages.
Which of the following occurs during anaphase II?
Sister chromatids separate and migrate toward opposite poles.
When homologous chromosomes cross over, what is the result?
Specific proteins break the two strands of nonsister chromatids and re-join them.
A human cell containing 22 autosomes and a Y chromosome is a __________.
Sperm
Identify all possible products of meiosis in plant and animal life cycles.
Spores, Gametes (sperm and eggs)
What is the best evidence telling you whether this cell is diploid or haploid?
The cell is diploid because it contains two sets of chromosomes.
For what purpose(s) might a karyotype be prepared?
The first three answers are correct; to determine whether a fetus is male or female for prenatal screening, to determine if a fetus has the correct number of chromosomes to detect the possible presence of chromosomal abnormalities such as deletions, inversions, or translocations
A human cell containing 22 autosomes and a Y chromosome is
a sperm
What is a locus?
The precise location of a gene on a chromosome
In a life cycle such as that shown in diagram II of the figure above, if the zygote's chromosome number is 10, which of the following will be true?
The sporophyte's chromosome number per cell is 10, and the gametophyte's is 5.
This chromosome has two chromatids, joined at the centromere. What process led to the formation of the two chromatids?
The two chromatids were formed by duplication of a chromosome.
Which of the following statements is correct regarding human X and Y chromosomes?
They are responsible for the determination of an individual's sex.
How do cells at the completion of meiosis compare with cells that have replicated their DNA and are just about to begin meiosis?
They have half the number of chromosomes and one-fourth the amount of DNA.
During mitosis or meiosis, sister chromatids are held together by proteins referred to as cohesins. Such molecules must have which of the following properties?
They must be removed before sister chromatids or homologous chromosomes can separate.
Look at the cell in the figure. Based on this figure, which of the following statements is true?
This cell is diploid.
Which of the following events might result in a human zygote with 45 chromosomes?
an error in either egg or sperm meiotic anaphase
Homologous chromosomes migrate to opposite poles during _____.
anaphase I
Which phase of meiosis is represented in the figure above?
anaphase I
During _____ sister chromatids separate.
anaphase II
In a cell undergoing meiosis, if centromeres of sister chromatids become disjoined and chromatids separate, what process has occurred?
anaphase II
The chromatids move toward the opposite poles of a dividing cell during ______.
anaphase II
For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes?
approximately 8.4 million
Sister chromatids __________.
are identical copies of each other formed during DNA synthesis
Refer to the figure above. Which of the progression of events listed corresponds to the series of events that occurs in the life cycle of animals?
diploid multicellular organism, meiosis, fertilization, zygote, mitosis
Fertilization produces a __________.
diploid zygote
Chromatids are separated from each other during which of the following processes?
during both mitosis and meiosis II
During which process does independent assortment of chromosomes occur?
during meiosis I only
The karyotype of one species of primate has 48 chromosomes. In a particular female, cell division malfunctions, and she produces one of her eggs with an extra chromosome (25). The most probable source of this error would be a mistake in which of the following processes?
either anaphase I or II of meiosis
Heritable variation is required for which of the following?
evolution
Which of the following structures is found in a pair of homologous chromosomes?
four sister chromatids
Meiosis II typically produces _____ cells, each of which is _____.
four, haploid
Spores and gametes differ in that __________.
gametes must fuse to form a zygote and continue development, but each spore can develop into an independent multicellular organisms on its own
After telophase II of meiosis, the chromosomal makeup of each daughter cell is
haploid, and the chromosomes are each composed of a single daughter chromosome.
After telophase I of meiosis, the chromosomal makeup of each daughter cell is
haploid, and the chromosomes are each composed of two chromatids.
In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following characteristics are most likely for the two chromosomes of the pair to have in common?
length, centromere position, staining pattern, and traits coded for by their genes
Genetic variation occurs when chromosomes are shuffled in fertilization and what other process?
meiosis
Human gametes are produced by _____.
meiosis
Homologous chromosomes move toward opposite poles of a dividing cell during
meiosis I
In the life cycle of fungi and some protists, which of the following processes leads to the formation of gametes?
meiosis in the diploid zygote
Which of the following elements do all sexual life cycles in eukaryotic organisms have in common?
meiosis, fertilization, and gametes
In sexually reproducing species, the chromosome number remains stable over time because __________ and __________ always alternate.
meiosis; fertilization
This cell must be undergoing ______ because ______ are associated with each other at the metaphase plate and chiasmata are present.
meiosis; homologous chromosomes
Homologous pairs of chromosomes are lined up independently of other such pairs during _____.
metaphase I
In a cell undergoing meiosis, if homologous chromosomes are aligned at the equator of the meiotic spindle, what process has occurred?
metaphase I
During _____ chromosomes align single file along the equator of a haploid cell.
metaphase II
Which phase of meiosis is represented in the figure above?
metaphase II
Which of the following processes leads directly to the formation of gametes in a plant's sexual life cycle?
mitosis in the gametophyte
Crossing over, resulting in an increase in genetic variation, occurs between _____.
nonsister chromatids of homologous chromosomes
A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure above. A certain female's number 12 chromosomes both have the blue gene and number 19 chromosomes both have the long gene. As cells in her ovaries undergo meiosis, her resulting eggs (ova) may have which of the following?
one chromosome 12 with one blue gene and one chromosome 19 with one long gene
Which of the following is the smallest unit of life that would contain a complete copy of the entire human genome?
one human somatic cell
A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure above. If a female of this species has one chromosome 12 with a blue gene and another chromosome 12 with an orange gene, and has both number 19 chromosomes with short genes, she will produce which of the following egg types?
one-half blue short and one-half orange short gene eggs
To visualize and identify meiotic cells at metaphase I with a microscope, what would you look for?
pairs of homologous chromosomes all aligned at the cell's center
A karyotype is a __________.
photograph of all of an individual's chromosomes
The synaptonemal complex __________.
physically connects homologous chromosomes during prophase I
Asexual reproduction __________.
produces offspring genetically identical to the parent
Crossing over occurs during __________.
prophase I
In a cell undergoing meiosis, if synaptonemal complexes form or are still present, what process or processes have occurred?
prophase I only
During _____ a spindle forms in a haploid cell.
prophase II
Which processes lead to most genetic variation in sexually reproducing organisms?
random fertilization, crossing over, and independent assortment of chromosomes in meiosis
What diagnostic procedures can a karyotype be used for?
screening for defective or abnormal numbers of chromosomes in an individual
Which of the following types of organisms has both diploid and haploid forms that exist as separate individuals?
some algae
A human cell containing 22 autosomes and a Y chromosome is __________
sperm
In alternation of generations, what is the diploid stage of a plant that follows fertilization called?
sporophyte
At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids.
telophase I
At the end of _____ and cytokinesis there are four haploid cells.
telophase II
How many genes are present in the human genome?
tens of thousands
What is crossing over?
the exchange of homologous portions of nonsister chromatids
Independent assortment of chromosomes during meiosis is a result of
the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I.
Meiosis I produces _____ cells, each of which is _____.
two , haploid
In a typical animal, mitosis produces ____________ while meiosis produces _____________.
two diploid daughter cells , four haploid daughter cells
Human somatic cells contain __________ set(s) of chromosomes and are therefore termed __________.
two; diploid
If the DNA content of a diploid cell in the G1 phase of the cell cycle is represented by x, then the DNA content of the same cell at metaphase of meiosis I would be 2x. If we continued to follow the cell lineage, the DNA content of a cell at metaphase of meiosis II would be __________.
x
Which of the following occurs during meiosis but not during mitosis?
Synapsis occurs.
Which event occurs only during prophase I of the first meiotic division?
Synapsis of homologous chromosomes occurs.
Which of the following statements about humans is true?
The 23rd pair, the sex chromosomes, determines whether the person is female (XX) or male (XY).
