Chapter 12, 13, & 14 Quiz

If a heterozygous plant is allowed to self-pollinate, what proportion of the offspring will also be heterozygous?

1/2

A cell contains 40 chromatids at the beginning of mitosis. How many chromosomes will it contain at the completion of cytokinesis?

20

2n = 6

3 pairs of different sizes

The ovum of a rabbit contains 22 chromosomes. How many chromosomes are in the somatic cells of a rabbit?

44

How many chromatids does a human somatic cell contain after interphase and just prior to mitosis?

92

Human blood groups are governed by three alleles, A, B, and O. A and B are codominant and O is recessive to both. A man who has type B blood and a woman who has type A blood could have children of which of the following phenotypes?

A, B, AB, or O

Regarding the cell cycle in humans, which are correct?

Cdks phosphorylate proteins in the respiratory chain Additional ATP is required to complete mitosis

Put these structures in their order at metaphase, starting form the pole.

Centrosome = 1, outermost Microtubule = 2 Kinetochore = 3 Chromosome = 4, innermost

Regarding the role of cohesin protein in maintaining cohesion between sister chromatids, which of the following statements is false?

During meiosis II, cohesion holds sister chromatids together along their lengths as the second meiotic spindle forms

Which are part of the interphase?

G1, S, G2

Regarding MPF, which are correct?

MPF activity peaks during the M phase during anaphase, the cyclin component is degraded MPF is formed by a cyclin and a Cdk

Regarding cell cycle checkpoints, which are correct?

The G1 checkpoint determines whether growth factors are present The S checkpoint determines whether the DNA has been damaged Most cells of the human body are in the G0 phase

Huntington's disease is an example of a genetic disorder cause by _____________.

a lethal dominant allele that afflicts an individuals later in life

_____________ occurs when a single gene affects the phenotype of many characters in an individual.

a pleiotropic effect

The F1 generation differed from the F2 in Mendel's experiment in that _____________.

all of the F1 showed the dominant phenotype, but only 3/4 of the F2 generation did

If an organism that is homozygous dominant is crossed with a heterozygote for that trait, the offspring will be _____________.

all of the dominant phenotype

An alternative version of a gene is called a(n) _____________.

allele

Fetal cells may be removed along with fluid from the womb by a process known as _____________.

amniocentesis

Somatic cells in animals differ from gametes in that somatic cells _____________.

are all of the cells of the body except for the gametes and their precursors

The function of the mitotic cell cycle is to produce daughter cells that _____________.

are genetically identical to the parent cell (assuming no mutation has occurred)

Sister chromatids differ from non sister chromatids in that sister chromatids _____________.

are the product of the S phase of the cell cycle and are two copies of one chromosome

A clone is the product of _____________.

asexual reproduction and mitosis

Which of the following structures is/are part of the mitotic spindle?

aster, centrosome, nonkinetochore microtubules, kinetochore microtubules

Which of the following statements correctly describes the difference(s) between mitosis and binary fission?

binary fission involves the replication and division of a single chromosome, whereas mitosis involves the division of multiple, replicated chromosomes

What is the difference between a benign tumor and a malignant tumor?

cells of benign tumors do not metastasize; those of malignant tumors do

Mendel studied _____________, heritable features that vary among individuals; each variant is called a _____________.

characters; trait

The complex of DNA and protein that makes up a eukaryotic chromosome is properly called _____________.

chromatin

A red bull is crossed with a white cow and all of the offspring are roan, an intermediate color that is caused by the presence of both red and white hairs. This is an example of genes that are _____________.

codominant

Somatic cells in humans differ from gametes in that human somatic cells _____________.

contains two sets of each of the 23 chromosome types

In animal cell mitosis, the cleavage furrow forms during which stage of the cell cycle?

cytokinesis

Which are part of the M phase?

cytokinesis mitosis

Regarding the cell cycle, which are correct?

cytokinesis occurs in the M phase the cell grows in the G2, S and G1 phase

Regardless of whether an organism is an animal, a plant, a fungus, or an algal cell, zygotes are _____________ and are formed during the _____________ of two _____________ gametes.

diploid; fertilization; haploid

During interphase, the genetic material of a typical eukaryotic cell in _____________.

dispersed in the nucleus as long strands of chromatin

Observations of cancer cells in culture support the hypothesis that cancer cells __________.

do not exhibit density-dependent inhibition

Achondraplasia, a type of dwarfism, and Huntington's disease are examples of _____________, with the exception that Huntington's allele is _____________.

dominant inherited disorders; lethal

In humans, which create cells with homologous chromosomes?

fertilization mitosis

What is the result when a diploid cell undergoes meiosis?

four haploid cells

_____________ are a group of genetically identical individuals produced by a process called _____________.

gametes; meiosis

Allelic variation is an important source of _____________ in a population.

genetic diversity

A pair of genetic structures carrying genes that control the same inherited characters are called __________.

homologous chromosomes

Which of the following occurs in meiosis, but not mitosis?

homologous chromosomes separate

Chromatids are

identical copies of each other if they are part of the same chromosome

You would know a dividing cell was a plant cell rather than an animal cell if you saw that _____________

it had formed a cell plate

The major contribution of sex to evolution is that _____________.

it provides a method to increase genetic variation

The process called _____________ reduces the chromosome number by _____________.

meiosis; two consecutive cell divisions

The effect of the environment on a phenotype is referred to as _____________.

multifactoral

Human ABO groups are best described as an example of _____________.

multiple alleles

Which of the following is a function of mitosis in humans?

multiplication of body cells

In meiosis, _____________ of _____________ cross over and form _____________.

nonsister chromatids; homologous pairs; chiasmata

A family tree that describes traits in families is called a _____________.

pedigree analysis

In humans, height and skin color have continuous variation in the population because of _____________.

polygenic inheritance

The zipper-like complex that forms in meiosis occurs during _____________ and is called the _____________ .

prophase I; synaptonemal complex

Checkpoints in the cell cycle control system _____________.

regulate the cell cycle through a variety of stop and go signals

Besides the fact that pea plants have a short generation time, the key to Mendel's successful plant-breeding experiments was that pea plants usually _____________.

self-pollinate

Which of the following events does not occur during interphase of the cell cycle?

separation of the sister chromatids

Genetic diversity requires _____________.

sexual reproduction, independent assortment, crossing over between nonsister chromatids of homologous chromosomes, and random fertilization

Which of the following phases of mitosis is essentially the opposite of prometaphase in terms of the nuclear envelope?

telophase

How many genes are present in the human genome?

tens of thousands

The term "true-breeding plants" means _____________.

that self-pollinating plants will always produce the same trait of a particular character

A cell biologist examined the DNA content of a cell from a fruit fly larva during the G1 phase and determined that it had 150 units of DNA. After measuring the DNA content of the same type of cell after the G2 phase, it was discovered that the cell had 300 units of DNA. How is this possible?

the DNA was replicated during the S phase of interphase, which occurs between the two G phases

DNA replication occurs

the S phase of interphase in both somatic and reproductive cells

One event occurring during prophase is _____________.

the beginning of the formation of a spindle apparatus

Which choice below is a basic difference between Mendel's particulate hypothesis and the hypothesis of blending inheritance?

the blending inheritance hypothesis, but not the particulate hypothesis, maintained that after a mating, the genetic material provided by each of the two parents is mixed in the offspring, losing its individual identity

In some bacteria, the process of cell division is initiated when the DNA of the bacterial chromosome begins to replicate at a specific place on the chromosome called the origin of replication. Which are the steps in this process?

the cell elongates the origin of replication splits into two copies

Which event(s) occur during anaphase?

the centromeres divide identical chromatids move to opposite poles the centrioles are at opposite ends a spindle made of microtubules is present

Which of the following events does not occur during prophase of mitosis?

the mitotic spindle breaks down

A couple just had a child who has Tay-Sachs disease. Neither parent has Tay-Sahcs, nor does anyone in their families. Which must be correct?

the mother is heterozygous for the disease any child they have will have a 25% chance of getting the disease the father is heterozygous for the disease

Which of the following events occurs during pro metaphase of mitosis?

the nuclear envelope fragments

What is a locus?

the precise location of a gene on a chromosome

Mendel's law of segregation states that _____________.

the two alleles for a heritable character segregate during gamete formation and end up in different gametes

Which of the following statements about homologous chromosomes is correct?

they have genes for the same traits at the same loci

Which of the following events occurs during telophase of mitosis?

two distinct daughter nuclei form in the cell

Somatic cells in humans contain __________ set(s) of chromosomes and are therefore termed __________.

two; diploid

At the end of mitosis, _____________ daughter cells that are genetically _____________ are formed, while at the end of meiosis, _____________ daughter cells that are genetically _____________ are formed.

two; identical; four; distinct

In incomplete dominance, the offspring _____________.

will have an appearance that's intermediate between those of the two parental types

If the two traits that Mendel looked at in his dihybrid cross of smooth yellow peas with wrinkled green peas had been controlled by genes that were located near each other on the same chromosome, then the F2 generation _____________.

would have deviated from the 9:3:3:1 phenotypic ratio that is predicted by the law of independent assortment

Color in squash is controlled by epistatic interactions in which color is recessive to no color. At the first locus white squash (W) is dominant to colored squash (w). At the second locus yellow (Y) is dominant to green (y). What is the phenotype of a squash with the genotype wwYy?

yellow