Exam 4 mastering

bacteria, eukaryotes, or both? Nuclear envelope fragments, permitting chromosome separation.

eukaryotes only

. During anaphase, the nonkinetochore microtubules _________ and move past each other, and the kinetochore microtubules ______

lengthen; shorten.

During which part of meiosis (meiosis I or meiosis II) do the two alleles of a gene separate? During which phase does the separation occur?

meiosis I, anaphase

Which of the following parental genotypes would yield a 1:1:1:1 phenotypic ratio in the offspring? aaBb, aabb aaBb, AaBb AaBb, AaBb AaBb, aabb

AaBb, aabb

How could the botanist best determine whether the genotype of the green-pod plant is homozygous or heterozygous? Cross the green-pod plant with another green-pod plant. Self-pollinate the green-pod plant. Cross the green-pod plant with a yellow-pod plant.

Cross the green-pod plant with a yellow-pod plant.

You cross a true-breeding red-flowered snapdragon with a true-breeding white-flowered one. All of the F1 are pink. What does this say about the parental traits? Pink is dominant, and red and white are recessive. Red is completely dominant. Both red and white are pleiotropic. Red shows incomplete dominance over white.

Red shows incomplete dominance over white.

DNA replicates

S

Height in humans generally shows a normal (bell-shaped) distribution. What type of inheritance most likely determines height? a combination of polygenic inheritance and environmental factors a combination of complete dominance and environmental factors a combination of multiple alleles and codominance a combination of epistasis and environmental factors incomplete dominance

a combination of polygenic inheritance and environmental factors

What is an allele? a type of chromosome the dominant form of a gene a variety of pea plant used by Mendel the recessive form of a gene an alternative version of a gene

an alternative version of a gene

Homologous chromosomes migrate to opposite poles during _____. telophase II and cytokinesis prophase II metaphase II anaphase I metaphase I

anaphase I

Human meiosis 1 begins and ends with: a- 2 haploid cells and 4 haploid cells b- 1 4n (twice diploid) cell and 2 haploid cells c- 1 haploid cell and 2 diploid cells d- 1 diploid cell and 2 haploid

b- 1 4n (twice diploid) cell and 2 haploid cells

Bacteria, animals, or plants? Cells divide by constriction of a ring of protein.

bacteria and animals

tubular or tumbling like molecules function in binary fission (in bacteria) or cytokinesis (in animals and plants)

bacteria and plants

Chromosome separation begins at the origin of replication on the DNA

bacteria only

non-dividing cells exit cell cycle

before g1 checkpoint in g1 phase

bacteria, eukaryotes, or both? Chromosomes replicate before cell division.

both

bacteria, eukaryotes, or both? Replicated chromosomes separate by attaching to some other structural feature of the cell.

both

Human mitosis begins and ends as: a- 1 diploid cell and 2 haploid cells b-1 4n (twice diploid) cell and 2 haploid cells c- 1 4n (twice diploid) cell and 2 diploid cells d- 1 diploid cell and 2 diploid cells

c- 1 4n (twice diploid) cell and 2 diploid cells

Cytochalasin B is a chemical that disrupts microfilament formation. How would this interfere with cell division? DNA replication binary fission formation of the mitotic spindle formation of the cell plate cleavage

cleavage

Human meiosis II begins and ends with: a- 1 diploid cell and 2 haploid cells b- 1 diploid cells and 1 haploid cells c- 1 4n (twice diploid) cell and 2 diploid cells d- 2 haploid cells and 4 haploid cells

d- 2 haploid cells and 4 haploid cells

During telophase, the nonkinetochore microtubules __________

disassemble.

bacteria, eukaryotes, or both? Before separation, duplicated chromosomes condense.

eukaryotes only

The_____________ is a cell structure consisting of microtubules, which forms during early mitosis and plays a role in cell division.

mitotic spindle(s)

Is the DNA condensed in all or part of this phase? G1 S G2 M (prophase-early anaphase) End of M (late anaphase-telophase)

no no no yes yes

Are sister chromatids present in all or part of these phases: G1 S G2 M (prophase-early anaphase) End of M (late anaphase-telophase)

no yes yes yes no

The presence of a cell wall prevents the cell from dividing by constriction

plants

Asexual reproduction _____. is limited to plants leads to a loss of genetic material produces offspring genetically identical to the parent is limited to single-cell organisms requires both meiosis and mitosis

produces offspring genetically identical to the parent

Synapsis occurs during _____. telophase I and cytogenesis prophase II metaphase II anaphase II prophase I

prophase I

In alternation of generations, what is the diploid stage of a plant that follows fertilization called? gametophyte karyotype spore chiasmata sporophyte

sporophyte

At the end of _____ and cytokinesis there are four haploid cells. prophase II interphase anaphase I telophase II prophase I

telophase II

During mitosis, microtubules attach to chromosomes at ______________

the kinetochore(s).

Which of the following is found in binary fission but not in mitosis? The result produces 2 nuclei. Replicated strands of DNA separate. Replication of DNA begins at an origin. Following the process, a membrane separates the 2 copies. Duplicated chromosomes attach to the plasma membrane.

Duplicated chromosomes attach to the plasma membrane.

Cell divides, forming two daughter cells

End of M

How do cells acquire homologous chromosome pairs that carry the alleles that are independently assorted? Meiosis Mitosis Fusion of gametes DNA replication

Fusion of gametes

Cells will usually divide if they receive the proper signal at a checkpoint in which phase of the cell cycle? S G1 G2 M cytokinesis

G1

At this point, cell commits to go through the cycle

G1 checkpoint

Which of the following is true of an X-linked gene, but not of a Y-linked gene? he gene is present in both males and females. Sister chromatids separate during mitosis. It is expressed in half of the cells of either male or female. It does not segregate like other genes. It is only expressed in female offspring.

The gene is present in both males and females.

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

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

Meiosis II typically produces _____ cells, each of which is _____. two... diploid two ... haploid four ... haploid four ... identical to the other four ... diploid

four ... haploid

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

four ... one

Meiosis I produces _____ cells, each of which is _____. four ... haploid two... identical to the other two ... haploid two... diploid four ... diploid

haploid

In general, the frequency with which crossing over occurs between two linked genes depends on what? whether the genes are dominant or recessive the characters the genes code for the phase of meiosis in which the crossing over occurs how far apart they are on the chromosome whether the genes are on the X or some other chromosome

how far apart they are on the chromosome

Two organisms with genotype AaBbCcDdEE mate. These loci are all independent. What fraction of the offspring will have the same genotype as the parents? 9/64 4/3 1/16 1/4 3/4

1/16

A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain? 23 or 46, depending on the portion of prophase examined 46 or 92, depending on the portion of prophase examined 23 92 46

23

What number and types of chromosomes are found in a human somatic cell? 22 autosomes and 1 sex chromosome 44 autosomes and 2 sex chromosomes 21 autosomes and 2 sex chromosomes 45 autosomes and 1 sex chromosome n chromosomes

44 autosomes and 2 sex chromosomes

Which of the following statements most accurately describes the process of independent assortment? Alleles found on separate chromosomes segregate based upon their origin. Genes located on the same chromosome assort as an independent unit. Alleles of different genes segregate from one another in a random manner. Dominant alleles segregate with recessive alleles. Submit

Alleles of different genes segregate from one another in a random manner.

Which of the following correctly matches a phase of the cell cycle with its description? G2: cell division M: duplication of DNA S: immediately precedes cell division G1: follows cell division All of the above are correctly matched.

G1: follows cell division

Centrosome replicates

G2

Which of the following do you expect if an individual is heterozygous for the sickle-cell trait? He or she will be more apt to acquire a serious case of malaria. He or she will show some symptoms of the disease. He or she will not develop sickle-cell disease. He or she will have full-blown sickle-cell disease because the allele is dominant. None of the above.

He or she will show some symptoms of the disease.

How are sister chromatids and homologous chromosomes different from each other? They are not different. Homologous chromosomes and sister chromatids are both identical copies of each other. Homologous chromosomes are closely associated with each other in both mitosis and meiosis. Sister chromatids are only associated with each other during mitosis. Homologous chromosomes are identical copies of each other. One sister chromatid comes from the father, and one comes from the mother. 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. Sister chromatids are only formed during mitosis. Homologous chromosomes are formed during meiosis.

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.

Which of the following is true about a plant with the genotype AABbcc? It will not express the recessive c allele. It is heterozygous at two loci. It has recessive alleles at three loci. It is triploid. It is homozygous at two loci.

It is homozygous at two loci.

Folk singer Woody Guthrie died of Huntington's disease, an autosomal dominant disorder. Which statement below must be true? His daughters will die of Huntington's disease but not his sons. His sons will develop Huntington's disease but not his daughters. All of his children will develop Huntington's disease. It is very likely that at least one of Woody Guthrie's parents also have had the allele for Huntington's disease. There is not enough information to answer the question.

It is very likely that at least one of Woody Guthrie's parents also have had the allele for Huntington's disease.

Mitotic spindle begins to form

M

What process is responsible for the independent assortment of alleles? Mitosis Cytokinesis. Meiosis. DNA replication.

Meiosis

In his breeding experiments, Mendel first crossed true-breeding plants to produce a second generation, which were then allowed to self-pollinate to generate the offspring. How do we name these three generations? P1 ... P2 ... F P1 ... P2 ... P3 P ... F1 ... F2 F1 ... F2 ... F3 F ... P1 ... P2

P ... F1 ... F2

In humans, what determines the sex of offspring and why? The male determines sex because the sperm can fertilize either a female egg or a male egg. The chromosome contribution from both parents determines sex because the offspring uses all the parents' chromosomes. The female gamete determines sex because only the female gametes can have one of two functional sex chromosomes. The female gamete determines sex because only the female gamete provides cytoplasm to the zygote. The male gamete determines sex because each male gamete can contribute either an X or a Y chromosome.

The male gamete determines sex because each male gamete can contribute either an X or a Y chromosome.

Which of the following is true of kinetochores? They are located at the center of the centrosome; their function is to organize tubulin into elongated bundles called spindle fibers. They are sites at which microtubules attach to chromosomes. They are the primary centromere structures that maintain the attachment of the sister chromatids prior to mitosis. They attach to the ring of actin along the cytoplasmic surface of the plasma membrane, causing the actin to contract to form the cleavage furrow. They interdigitate at the cell's equator and then move apart, causing the cell to elongate.

They are sites at which microtubules attach to chromosomes.

Why is it difficult to observe individual chromosomes with a light microscope during interphase? They have uncoiled to form long, thin strands. They leave the nucleus and are dispersed to other parts of the cell. The spindle must move them to the metaphase plate before they become visible. Sister chromatids do not pair up until division starts. The DNA has not been replicated yet.

They have uncoiled to form long, thin strands.

Why do some species employ both mitosis and meiosis, whereas other species use only mitosis? They need meiosis if the cells are producing organs such as ovaries. They need only meiosis if they produce egg cells. They need both if they are producing animal gametes. They need only mitosis to make large numbers of cells such as sperm. A single-celled organism only needs mitosis.

They need both if they are producing animal gametes.

Which of the following is true of benign tumors, but not malignant tumors?

They remain confined to their original site

Which of the following statements are true of cytokinesis in plant cells? Select the two that apply. After chromosome separation is complete, a network of microfilaments forms near the plane of cell division that will separate the two new cells. Vesicles from the Golgi apparatus move along microtubules, coalesce at the plane of cell division, and form a cell plate. The plasma membrane of the parent cell grows inward, eventually joining with the cell plate. The cell plate consists of the plasma membrane and cell wall that will eventually separate the two daughter cells.

Vesicles from the Golgi apparatus move along microtubules, coalesce at the plane of cell division, and form a cell plate. ; The cell plate consists of the plasma membrane and cell wall that will eventually separate the two daughter cells.

Bob has a genetic condition that affects his skin. Bob's wife, Eleanor, has normal skin. No one in Eleanor's family has ever had the skin condition. Bob and Eleanor have a large family. Of their eleven children, all six of their sons have normal skin, but all five of their daughters have the same skin condition as Bob. X-linked dominant autosomal recessive X-linked recessive autosomal dominant Y-linked

X-linked dominant

The ________ are the organizing centers for microtubules involved in separating chromosomes during mitosis.

centrosome(s)

During interphase, most of the nucleus is filled with a complex of DNA and protein in a dispersed form called _________

chromatin.

In most eukaryotes, division of the nucleus is followed by _______, when the rest of the cell divides.

cytokinesis

True or false? The principle of independent assortment is best illustrated by events that take place during metaphase II, during which sister chromatids segregate independently of each other.

false

In dividing cells, most of the cell's growth occurs during ___________

interphase.

In some organisms, such as certain fungi and algae, cells undergo the cell cycle repeatedly without subsequently undergoing cytokinesis. What would result from this? large cells containing many nuclei inability to duplicate DNA division of the organism into many cells, most lacking nuclei a rapid rate of gamete production a decrease in chromosome number

large cells containing many nuclei

Suppose that the botanist carried out the test cross described in Parts A and B and determined that the original green-pod plant was heterozygous (Gg). Which of Mendel's findings does her test cross illustrate? law of independent assortment chromosome theory of inheritance linkage law of segregation

law of segregation

During prophase, the microtubules of the mitotic spindle..

lengthen

During _____ chromosomes align single file along the equator of a haploid cell. telophase I and cytokinesis metaphase I anaphase I prophase I metaphase II

metaphase II

Does the cell contain twice as much DNA in this phase as it did in the G1 phase? G1 S G2 M (prophase-early anaphase) End of M (late anaphase-telophase)

no yes yes yes yes

During _____ a spindle forms in a haploid cell. anaphase II telophase I and cytokinesis prophase II metaphase II prophase I

prophase II

DNA replication produces two identical DNA molecules, called __________, which separate during mitosis.

sister chromatid(s)

After chromosomes condense, _______________ is the region where the identical DNA molecules are most tightly attached to each other.

the centromere(s)

How many genetically unique types of gametes could be produced by an individual with the genotype RrYY? Three Eight Two One

two

Various procedures can be used to detect genetic disorders before birth. Among the tests discussed in this chapter, which is the least invasive (list first), and which two allow the chromosomes of the fetus to be examined? ultrasound imaging ... fetoscopy... amniocentesis ultrasound imaging ... chorionic villus sampling ... amniocentesis chorionic villus sampling ... fetoscopy ... amniocentesis amniocentesis ... ultrasound imaging ... chorionic villus sampling amniocentesis ... fetoscopy ... chorionic villus sampling

ultrasound imaging ... chorionic villus sampling ... amniocentesis