Bio Exam 4

If a version of a gene is dominant, then_____ It will more often be passed on to offspring Its sequence overwrites other versions of the gene a single copy of it will produce its trait Two copies of it are required to produce its trait not sure

a single copy of it will produce its trait

An insect that has the genotype EeGGcc will have the same phenotype as an insect with the genotype _____. EEGgcc EEggcc eeggcc EEGGCc

EEGgcc

A man who has TYPE B blood marries a woman who has TYPE A blood. Suppose both of their fathers have TYPE O blood. What blood types are possible for their children? Type AB Type A and B Types AB and O Types A, B, AB, O

Types A, B, AB, O

Centromeres divide and sister chromatids become full-fledged chromosomes during _____. metaphase interphase anaphase telophase prometaphase

anaphase

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

anaphase I

During _____ sister chromatids separate. anaphase II prophase I prophase II interphase metaphase I

anaphase II

A biochemist measured the amount of DNA in cells growing in he laboratory and found that the quantity of DNA in a cell doubled a. between prophase and anaphase of mitosis. b. between the G1 and G2 phases of the cell cycle. c. during the M phase of the cell cycle. d. between prophase I and prophase II of meiosis.

b

A fruit fly somatic cell contains 8 chromosomes. This means that _ _ _ _ different combinations of chromosomes are possible in its gametes. a. 8 b. 16 c. 32 d. 64

b

Edward was found to be heterozygous (Ss) for sickle-cell trait. The alleles represented by the letters S and s are a. linked. b. on homologous chromosomes. c. both present in each of Edward's sperm cells. d. on the same chromosome but far apart.

b

If a fragment of a chromosome breaks off and then reattaches to the original chromosome but in the reverse direction, the result- ingchromosomalabnormalityiscalled a deletion. an inversion. a translocation. a nondisjunction.

b

If an intestinal cell in a grasshopper contains 24 chromosomes, then a grasshopper sperm cell contains____ chromosomes d. 48 a. 6 b. 12 c. 24 d. 48

b

It is difficult to observe individual chromosomes during inter- phase because the DNA has not been replicated yet. they are in the form of long, thin strands. they leave the nucleus and are dispersed to other parts of the cell. homologous chromosomes do not pair up until division starts.

b

A cell replicates its entire chromosomal DNA only __________. to repair damage caused by mutation when it makes protein when the cell needs RNA before it is about to divide

before it is about to divide

Which of the following conditions would prevent cell division due to density-dependent factors? presence of growth factors being completely surrounded by other cells being attached to other cells of the same tissue being attached to an extracellular surface

being completely surrounded by other cells

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

metaphase II

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

prophase I

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

prophase II

Because it is passed essentially intact from father to son, Y chromosome research has been particularly useful in improving our understanding of __________. chromosome disorders pleiotropy X-linked human diseases recent human evolution

recent human evolution

One version of a gene may encode __________, whereas a different version of the same gene may encode __________. white eyes; white coat white eyes; brown coat red eyes; white coat red eyes; white eyes

red eyes; white eyes

If we do a test cross to determine the genotype of a black Lab with normal vision, which of the following results would indicate that it is heterozygous for black coat and homozygous for normal vision? 1 black, normal vision : 1 chocolate, normal vision 1 black, normal vision: 1 chocolate, blind 3 black, normal vision: 1 chocolate, blind 3 black, blind: 1 chocolate, normal vision

1 black, normal vision : 1 chocolate, normal vision

If the two characteristics that Mendel looked at in his dihybrid cross of smooth yellow peas with wrinkled green peas had been controlled by genes that were located close together on the same chromosome, then the F2 generation ______ would have contained no individuals that were heterozygous for both genes would have contained four phenotypes in a 9:3:3:1 ratio would have contained only individuals that were heterozygous for both genes would have deviated from the 9:3:3:1 phenotypic ratio that is predicted by the law of independent assortment

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

Assume that in cattle a spotted coat is dominant to an even coat, short horns are dominant to long horns, and the traits for coat type and horn length assort independently. In a cross between cattle that are each heterozygous for both traits, what proportion of their offspring are expected to have long horns? 1/16 3/16 1/4 9/16

1/4

A woman with type O blood is expecting a child. Her husband is type A. Both the woman's father and her husband's father had type B blood. What is the probability that the child will have type O blood? 0% 25% 50% 75%

50%

Crossing over of chromosomes during meiosis shuffles parental chromosomes, resulting in a genetically unique child. Select the three true statements about crossing over. Chromosomes from the egg and the sperm undergo crossing over immediately after fertilization occurs. During prophase I of meiosis I, homologous paternal and maternal chromosomes pair up and undergo crossing over. Chiasmata in nonsister chromatids decrease the genetic variability produced during crossing over. A hybrid chromosome that has crossed over will contain pieces of both the maternal and paternal chromosomes. During meiosis II, sister chromatids separate into four different gametes.

A hybrid chromosome that has crossed over will contain pieces of both the maternal and paternal chromosomes. During meiosis II, sister chromatids separate into four different gametes. During prophase I of meiosis I, homologous paternal and maternal chromosomes pair up and undergo crossing over.

You have one tree that produces big yellow apples and another tree that produces small red apples. When the two are crossed, you find that half the offspring trees produce big red apples and half produce big yellow apples. What are the genotypes of the parents? A = big apples; a = small apples; R = red apples; r = yellow apples. Aarr and aa RrAARr and AArr AaRr and AaRr AArr and aaRr

AArr and aaRr

The sister chromatids separate and begin moving toward opposite poles of the cell during which phase of mitosis? Metaphase Interphase Telophase Anaphase Prophase

Anaphase

In the laboratory, cancer cells fail to show density-dependent inhibition of growth in cell culture. What is one explanation that could account for this? Cancer cells continuously secrete growth factors into the cell culture medium. Cancer cells have inactive receptors for growth factors. Cancer cells are unable to attach to a surface and grow. Cancer cells continue to die at a rate that is equal to their growth.

Cancer cells continuously secrete growth factors into the cell culture medium.

Imagine a particular trait that is determined by a single gene. If this gene is present in two forms, how can you tell which allele is dominant and which is recessive? Cross one of the F1 individuals to either of the parents. The trait that is most common in the population is the one determined by the dominant allele Do a test cross between two true-breeding individuals and observe the trait expressed by the F1 plants. Do a test cross between two true-breeding individuals and observe the characteristic expressed by the F2 plants.

Do a test cross between two true-breeding individuals and observe the trait expressed by the F1 plants.

When examining cells in the laboratory, you notice that a particular cell has half as much DNA as the surrounding cells. It appears that this cell's cell cycle halted at checkpoint _____. G1 G0 M phase G2

G1

Imagine that a deaf male has a child with a hearing female. You know that the male must have the genotype dd, but the female could be either Dd or DD. If the couple's first child has hearing, can you determine the mother's genotype? (Hint: Draw Punnett squares for the two possible crosses.) Her genotype must be DD. Her genotype must be Dd. Her genotype must be dd. Her genotype cannot be determined.

Her genotype cannot be determined.

A man who has TYPE B blood marries a woman who has TYPE A blood. Suppose both of their fathers have TYPE O blood. What would be the genotype for the woman? IAIA IAi IAIB

IAi

A man who has TYPE B blood marries a woman who has TYPE A blood. Suppose both of their fathers have TYPE O blood. What would be the genotype for the man? IBIB IBi IAIB

IBi

During binary fission, each copy of the duplicating chromosome moves to opposite ends of the cell. What does this achieve? It ensures the formation of two complete nuclei around each of the chromosomes. It ensures that each daughter cell receives one copy of the chromosome. This keeps the separate chromosomes together. It causes the cell to elongate.

It ensures that each daughter cell receives one copy of the chromosome.

The chromosomes line up in the center of the cell during which phase of mitosis? Telophase Anaphase Metaphase Prophase Interphase

Metaphase

How have Mendel's laws fared as we have learned more about cell biology and processes such as meiosis? Our new knowledge has confirmed all of Mendel's predictions and laws Our new knowledge has led to the rejection of all of Mendel's laws. Our new knowledge shows that the Law of Segregation is incorrect, but it has proved the Law of Independent Assortment to be valid Our new knowledge has helped to explain some of the exceptions to Mendel's laws of inheritance.

Our new knowledge has helped to explain some of the exceptions to Mendel's laws of inheritance.

The centrosomes move away from each other and the nuclear envelope breaks up during which phase of mitosis? Interphase Prophase Anaphase Telophase Metaphase

Prophase

The chromosomes arrive at the poles and nuclear envelopes form during which phase of mitosis? Anaphase Telophase Prophase Metaphase Interphase

Telophase

It's difficult to observe individual chromosomes during interphase because ________. The DNA has not been replicated yet they are in the form of long, thin strands they leave the nucleus and are dispersed to other parts of the cell

The DNA has not been replicated yet they are in the form of long, thin strands

What must happen before a cell can begin mitosis? The nucleus must divide in two. The nuclear envelope must break up. The sister chromatids must be separated. A mitotic spindle must form. The chromosomes must be duplicated.

The chromosomes must be duplicated.

In a particular species of mammal, black hair (B) is dominant to green hair (b), and red eyes (R) are dominant to white eyes (r). When a BbRr individual is mated with a bbrr individual, offspring are produced in a ratio of 5 black hair and red eyes : 5 green hair and white eyes : 1 black hair and white eyes : 1 green hair and red eyes. Which of these explanations accounts for this ratio? The genes for hair color and eye color are linked. The genes for hair color and the genes for eye color are carried on different chromosomes. The expected results did not take genetic recombination into account. Green-haired individuals have a higher prenatal mortality than black-haired individuals.

The genes for hair color and eye color are linked.

Within one chromosome, what is the relationship between the sequence of bases in DNA of one sister chromatid compared to the other? The sequences are similar, but not identical. The sequence in one chromatid is complementary to the sequence in the other. The sequences are identical. The sequences are unrelated.

The sequences are identical.

If the gene for seed color that Mendel studied exhibited pleiotropy, how might a green pea be different from a yellow pea? Obviously, a green pea would be green and a yellow pea would be yellow, with no other differences. With pleiotropy, there would be other differences between the peas - for example, green peas may also be larger, ripen earlier, and be more sensitive to frost. With pleiotropy, the green pea would not be as dark a green and the yellow pea would have some shades of green. With pleiotropy, the heterozygotes would have patches of yellow and green coloration instead of being pure yellow.

With pleiotropy, there would be other differences between the peas - for example, green peas may also be larger, ripen earlier, and be more sensitive to frost.

If you are a male, the Law of Independent Assortment indicates that your gametes contain _____. only the chromosomes and alleles you inherited from your father only the chromosomes you inherited from your father, although some of the alleles you inherited from your mother may have been spliced in through recombination a random mix of the chromosomes you inherited from each parent only the chromosomes and alleles you inherited from your mother

a random mix of the chromosomes you inherited from each parent

A phenotypic ratio of 9:3:3:1 in the offspring of a cross indicates that _____. one parent is homozygous dominant and one parent is heterozygous one parent is homozygous dominant and one parent is homozygous recessive one parent is heterozygous and one parent is homozygous recessive both parents are homozygous dominant both parents are heterozygous for both genes

both parents are heterozygous for both genes

Cytochalasin B is a chemical that disrupts microfilament formation. This chemical would interfere with a. DNA replication b. formation of the mitotic spindle. c. cleavage. d. formation of the cell plate.

c

Whether an allele is dominant or recessive depends on a. how common the allele is, relative to other alleles b. whether is is inherited from mother or the father c. whether it or another allele determines the phenotype when both are present d. whether or not it is linked to other genes

c

which of the following is NOT a function of mitosis in humans? a. repairofwounds b. growth c. production of gametes from diploid cells d. replacement of lost or damaged cells

c

Asexual and sexual reproduction differ in that sexual reproduction _____. is the only way multicellular organisms can reproduce will produce offspring identical to the parents can produce great variation among the offspring is the only way single-celled organisms can reproduce

can produce great variation among the offspring

At the end of the mitotic (M) phase, the cytoplasm divides in a process called _________________ replication condensation telophase meiosis cytokinesis

cytokinesis

A man with type B blood and a woman who has type A blood could have children of which of the following phenotypes? a. A or B only b. AB only c. AB or O d. A, B, AB, or O

d

A micrograph of a dividing cell from a mouse showed 19 ch romo- somes, each consisting of two sister chromatids. During which of the following stages of cell division could such a picture have been taken? (Explain your answer.) a. prophase of mitosis b. telophaseII of meiosis c. prophase I of meiosis d. prophase II of meiosis

d

Two fruit flies with eyes of the usual red color are crossed, and their offspring are as follows: 77 red-eyed males, 71 ruby-eyed males, 152 red-eyed females. The allele for ruby eyes is a. autosomal (carried on an autosome) and dominant. b. autosomalandrecessive. c. sex-linked and dominant. d. sex-linked and recessive.

d

If it weren't for _____, chromosome number would double with every generation of sexual reproduction. meiosis mitosis crossing over fertilization

meiosis

Why are individuals with an extra chromosome 21, which causes Down syndrome, more numerous than individuals with an extra chromosome3orchromosome16? a. There are probably more genes on chromosome 21 than on the o t hers. b. Chromosome 21 is a sex chromosome and chromosomes 3 and 16 are not .c. Down syndrome is not more common, just more serious. d. Extra copies of the other chromosomes are probably fatal.

d

A cross between two individuals with black eyes and green skin which results in an individual with orange eyes and white skin is an example of a _____ cross. test dihybrid monohybrid difficult trihybrid

dihybrid

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

four ... haploid

Fertilization joins _____ to produce a _____. diploid zygotes ... gamete haploid zygotes ... diploid gamete homologous chromosomes ... tetrad haploid gametes ... diploid zygote

haploid gametes ... diploid zygote

Mendel observed that pairs of alleles were separated or segregated in gametes and that they were rejoined in fertilization. We know that pairs of _____ are segregated in _____ and then are rejoined through fertilization. linked genes ... meiosis homologous chromosomes ... crossing over homologous chromosomes ... meiosis gametes ... meiosis

homologous chromosomes ... meiosis

During anaphase I, __________. chromosomes line up in one plane homologous chromosomes separate and migrate toward opposite poles sister chromatids separate and migrate toward opposite poles nuclear membranes re-form

homologous chromosomes separate and migrate toward opposite poles

Which processes lead to most genetic variation in sexually reproducing organisms? independent orientation of chromosomes in meiosis crossing over random fertilization cytokinesis

independent orientation of chromosomes in meiosis crossing over random fertilization

Nucleoli are present during _____. interphase metaphase prophase anaphase prometaphase

interphase

A fragment of chromosome 21 reattaches to chromosome 21, but in the reverse direction. What is the name given to this change? deletion duplication trisomy 21 inversion

inversion

Looking through a light microscope at a cell undergoing division, you see that the condensed chromosomes have lined up along the midline of the cell. The homologous pairs are NOT joined in tetrads. Each chromosome takes its own place in line, independentof its homolog. You are witnessing _____. interphase metaphase of mitosis metaphase of meiosis I telophase of either mitosis or meiosis II

metaphase of mitosis

Which of the following is a correct representation of an event that occurs in mitosis? metaphase—chromosomes line up on the equatorial plane. prometaphase—there is movement of the chromosomes to the poles. prophase—chromosomes uncoil. anaphase—the nuclear envelope disappears.

metaphase—chromosomes line up on the equatorial plane.

Mendel formulated his principles of inheritance based on _____. a detailed understanding of meiosis, fertilization, and the other chromosomal processes that are involved. observations on the outcomes of breeding experiments. The underlying processes were unknown at the time.existing knowledge of chromosomal processes that he combined with insights from his own breeding experiments little-known works by earlier scientists.

observations on the outcomes of breeding experiments.

Duplication of the chromosomes to produce sister chromatids _____. occurs in meiosis but not in mitosis occurs in mitosis but not in meiosis occurs in both mitosis and meiosis does not occur in either type of cell division

occurs in both mitosis and meiosis

Spindle fibers attach to kinetochores during _____. interphase prometaphase anaphase metaphase telophase

pro metaphase

Chromosomes become visible during _____. interphase anaphase prophase metaphase prometaphase

prophase

During which stages of mitosis are chromosomes replicated? Prophase pro metaphase metaphase anaphase telophase

prophase prometaphase metaphase

Which of the following statements is true? Newly formed daughter cells contain replicated chromosomes. A non-replicated chromosome is also called a sister chromatid sister chromatids contain the same genetic information a replicated chromosome contains two sister chromatids not sure

sister chromatids contain the same genetic information a replicated chromosome contains two sister chromatids

During anaphase II, __________. homologous chromosomes separate and migrate toward opposite poles sister chromatids separate and migrate toward opposite poles the cell is diploid nuclear membranes re-form

sister chromatids separate and migrate toward opposite poles

An example of a cell that is 2n is a __________. gametophyte haploid cell somatic cells perm or ovum

somatic cells

Mitosis occurs in _____; meiosis occurs in _____. somatic or body cells ... germ cells in the testes or ovaries germ cells in the testes or ovaries ... somatic or body cells sexually reproducing organisms ... asexually reproducing organisms adult organisms ... zygotes and early embryo

somatic or body cells ... germ cells in the testes or ovaries

Cytokinesis often, but not always, accompanies _____. prometaphase metaphase interphase telophase anaphase

telophase

Which phase of the cell cycle is essentially the opposite of prophase in terms of changes to the nucleus Anaphase interphase telophase metaphase

telophase

At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids. telophase I interphase telophase telophase II metaphase II

telophase I

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

telophase II

Cystic fibrosis is inherited in an autosomal recessive pattern. Males who have cystic fibrosis are usually sterile. Furthermore, the disease is often lethal before the age of reproduction. Even though people with the disease rarely reproduce, cases continue to arise because __________. people continue to make inappropriate lifestyle choices mosquitoes can transfer the disease from person to person new mutations continually introduce this harmful condition into the population the harmful allele "hides" inside heterozygous individuals and one-fourth of the offspring of two heterozygotes should be afflicted

the harmful allele "hides" inside heterozygous individuals and one-fourth of the offspring of two heterozygotes should be afflicted

Two parents of mixed ethnicity have twins, one of which is born with very light skin and one of which is born with very dark skin. This is because of __________. the inheritance of two linked skin color genes the pleiotropic effects of skin color genes the polygenic nature of skin color genes exposure to sunlight

the polygenic nature of skin color genes

In a test cross, F2 refers to ____ the second filial generation, or the "grandchildren" of the original mating pair the original mating pair the 1st filial generation the grandparents of the 1st generation

the second filial generation, or the "grandchildren" of the original mating pair

During mitosis, the chromosomes move because _____. of the duplication of the centrosome they diffuse within the nucleus to areas where they are less concentrated they slide along microfilament bundles they attach to a dynamic, precisely regulated mitotic spindle

they attach to a dynamic, precisely regulated mitotic spindle

As we now understand it, the Law of Independent Assortment applies _____. to all pairs of genes to pairs of genes that are on different chromosomes, but NOT to pairs of genes that are close together on the same chromosome only to pairs of genes that are close together on the same chromosome only to sex-linked genes

to pairs of genes that are on different chromosomes, but NOT to pairs of genes that are close together on the same chromosome

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

two ... haploid

During prophase a homologous pair of chromosomes consists of _____. four chromosomes and two chromatids twochromosomes and two chromatids one chromosome and two chromatids one chromosome and four chromatids two chromosomes and four chromatids

two chromosomes and four chromatids

At the end of telophase I of meiosis, as cytokinesis occurs, there are __________. two diploid cells four haploid cells one haploid ovum and three polar bodies two haploid cells

two haploid cells