1. Eukaryotic chromosomes are composed of a complex of 60% protein and 40% DNA. The name of this chemical complex is a
If a eukaryotic cell has a single set of chromosomes, it is called
The physical map of the array of chromosomes is called a(n)
The physical distribution of cytoplasmic material into the two daughter cells is called
growth and reproduction
Which of the following cell functions are maintained by cell division
. single, circular, uncoated, double stranded DNA molecule.
The bacterial genome exist as a
plasma membrane pinches inward constricting the cell.
The division of a bacterial cell occurs as the
. In the human, the body cells (non-sex cells) contain two sets of chromosomes totaling
. homologous chromosomes
The two copies of each chromosome in body cells are called
Before cell division of the body cells, each homologue replicates into two parts. These parts are connected by a centromere and are called
. G1 to S to G2 to M to C
Which of the following sequence of cell-cycle phases is characteristic of eukaryotes?
The primary growth phase of a cell is
The phase of the cell cycle during which the cytoplasm divides to form two cells is
The cell organelles replicate prior to genomic separation in ______ phase
The first stage of mitosis, when the chromosomes become visibly shorter and thicker is
The chromosomes line up at the equator of the spindle during
A. G1 + G2 + S
Which one of the following represents interphase? a. G1 + G2 + Sb. S + M + Cc. prophase + metaphase + anaphase + telophased.
cytokinesis + mitosise. G0 + G1 + G2
Microtubules become shorter, pulling chromatids to the ends of the spindle, during
Which of the following is essentially the reverse of prophase? a. anaphaseb. interphasec.
metaphased. telophasee. cytokinesis
forming a cleavage furrow that pinches the cell into two
Animal cells typically achieve cytokinesis by
forming a cell plate across the middle of the cell
Plant cells typically achieve cytokinesis by
Which of the following is not a checkpoint for cell cycle control in a eukaryotic cell? a. G1/Sb. G2/Mc. spindled. MFP
cyclins and cyclin-dependent kinases.
The proteins that participate in the functioning of the checkpoints for cell cycle control are
Recent studies on cell cycle controls have revealed that animal cells can employ certain factors to override the inhibitory controls of cell division. These belong to a class of proteins called
The actual process of cell division in prokaryotic cells is called
Nuclear division in eukaryotic cells is called
It means that chromosomes from the red blood cells of the alligator will be examined with a microscope, photographed, counted, lined up with their respective homologous partner, and displayed.
A cell biologist is conducting a karyotype procedure on alligator red blood cells. Exactly what does this mean? a. It means that red blood cells from the alligator will be examined with a microscope and the nuclei will be counted.b. It means that red blood cells from the alligator will be examined using restriction enzymes to count the number of centromeres that are present on the chromosomes.c.
It means that chromosomes from the red blood cells of the alligator will be examined with a microscope, photographed, counted, lined up with their respective homologous partner, and displayed.d. It means that chromosomes from the red blood cells of the alligator will be examined with a microscope to determine the amount of hemoglobin present.
b. The homologous chromosomes have all been copied through DNA replication and are now sister chromatids.
In humans the diploid number of chromosomes is 46. The haploid number is 23. Prior to mitosis in the cell cycle, the cell is in the G2 phase. Which of the statements is true? a. The homologous chromosomes are lined up on the equator.
b. The homologous chromosomes have all been copied through DNA replication and are now sister chromatids.c.
The homologous chromosomes have been pulled to their respective poles by the spindle apparatus.d. The homologous chromosomes have not been replicated yet.e. The homologous chromosomes are now in the haploid or n condition.
Cytokinesis occurs right after
The fusion of male gamete cells with female gamete cells is called
Diploid organisms use meiosis for the development of gametes. Meiosis consists of how many rounds of nuclear division?
The pairing of chromosomes along their lengths which is essential for crossing over is referred to as
The cell produced by the fusion of an egg and a sperm is the
e. two copies of each chromosome.
The zygote has a. one copy of each chromosome.b. one full haploid complement of chromosomes.c. chromosomes identical to those of a sperm cell.d. chromosomes identical to those of an egg cell.
e. two copies of each chromosome.
The reduction division that separates two haploid complements from each other is called a. mitosis.b. meiosis.c. syngamy.d.
haploid division.e. binary fission.
All of the following animal cells are diploid except
The point of connection between the two sister chromatids before anaphase of mitosis separates them is called the a. homologue.b. kinetochore.c. centromere.
d. microtubule complex.e. synapsis.
Which of the following produces identical cells?
39. In one of the first steps in meiosis, the a. clearly defined spindle apparatus appears in the center of the cell.
b. chromatids separate and move to opposite ends of the cell.c. half chromosomes are made inactive.d. homologous pairs of chromosomes pair up along their length.
e. chromosomes become invisible.
In one of the first steps in meiosis, the a. clearly defined spindle apparatus appears in the center of the cell.b. chromatids separate and move to opposite ends of the cell.c. half chromosomes are made inactive.
d. homologous pairs of chromosomes pair up along their length.e. chromosomes become invisible.
Chromosomes exchange genetic information by
41. Between the two divisions of meiosis there is a. a full cell cycle.b. a pairing of homologues.c. replication of some parts of the chromosomes.
d. no S phase.e. random combination among chromatids.
Crossing over of chromosomes takes place in
c. a lattice of proteins that holds homologues together.
The synaptonemal complex develops early in meiosis. It is a. a cluster of chromatids at the end of the cell.b. a framework of microtubules that organize chromatids.c. a lattice of proteins that holds homologues together.
d. a set of two homologues lined side by side.e. the wound up regions of DNA molecules.
The four haploid cells resulting from meiosis may further divide by mitosis in all of the following organisms except?
Sexual reproduction increases genetic variability through all of the following except
b. DNA replication errors could be corrected by recombination.
One of the most likely explanations for the evolutionary origin of sexual reproduction is that a. organisms could then move onto land.b.
DNA replication errors could be corrected by recombination.c. more and larger offspring could be produced.d. haploid cells require less energy and raw materials.
a. In anaphase I, where how one pair separates does not affect how any other pair separates.
Which of the following is an explanation for independent assortment, a factor in producing genetic variability? a. In anaphase I, where how one pair separates does not affect how any other pair separates.b. Chromosomes are divided into daughter cells in a random fashion.c. In prophase I, which chromosomes pairs with which other one is completely random.
d. Each chromosome is capable of a different function.e. Chromosomes can have different functions in various types of cells of the same organism.
b. Mitosis is nuclear division, which ultimately leads to diploid somatic cells. Meiosis is nuclear division, which ultimately leads to haploid gametes.
Meiosis and mitosis are both processes that involve nuclear division.
What is the difference between the two? a. Mitosis is nuclear division, which ultimately leads to haploid gametes. Meiosis is nuclear division, which ultimately leads to diploid somatic cells.
b. Mitosis is nuclear division, which ultimately leads to diploid somatic cells. Meiosis is nuclear division, which ultimately leads to haploid gametes.
c. Mitosis is nuclear division, which ultimately leads to diploid gametes. Meiosis is nuclear division, which ultimately leads to haploid somatic cells.d.
Mitosis is nuclear division, which ultimately leads to syngamy. Meiosis is nuclear division, which ultimately leads to zygotes.
. After fertilization, the resulting zygote develops by which of the following processes?
The majority of the meiosis I is spent in prophase I and metaphase I.
After metaphase I is completed, anaphase I and telophase I quickly proceed, thus ending meiosis I. What immediately follows meiosis I?
All of the following are processes that promote new genetic combinations except
there is a reduction in the chromosome number during two separate nuclear and cell divisions to produce gametes.
Meiosis also has been called reduction division because
You are studying mitosis in an organism that has 28 chromosomes as its diploid number. How many chromosomes will the cell have after mitosis, but before cytokinesis? a. 7b. 14c. 28d. 56
14b. 28c. 56d. cannot determine from the information provided
b. Crossing over takes place between sister chromatids.
Which of the following statements about crossing over is false? a. Crossing over takes place between non-sister chromatids.
b. Crossing over takes place between sister chromatids.c. Recombination nodules may be observed.d. Sites of crossing over are called chiasmata.
b. independent assortment.
In 95% of cases of Down’s syndrome, there is an entire extra chromosome 21 in every cell. This aneuploid condition is the result of a. improper crossing over.b. independent assortment.
c. nondisjunction.d. achiasmate segregation.
A diploid organism that has two identical alleles for the same trait is called _______ for that particular trait.
A gene for a particular trait that is only expressed in the presence of another gene of the same kind is called a(n)
a. heredity occurs within species, and species “breed true.”
One of the general principles of biology that was accepted before much was known about genetics was that a. heredity occurs within species, and species “breed true.”b. hybrids can form occasionally from any two parents.
c. mythical monsters can no longer be found on Earth.d. traits are transmitted directly.e. traits of both parents are blended in the offspring.
Mendel referred to the trait that was expressed in the hybrid, F1 or first filial generation as a. recessive.
3 yellow: 1 green
In a typical Mendel experiment on pea-seed color, if the dominant yellow seed-bearing plant was crossed with the recessive green seed-bearing plant, the F2 generation will show what ratio of each kind?
e. if a given allele is present, its effects will be seen in the individual.
Mendel’s understanding of the inheritance of traits in peas, expressed in modern language, included all of the following except a.
parents transmit information encoded in genes.b. each individual contains two genes for each trait.c. not all genes are identical; alternative forms (alleles) exist.d.
each of the alleles present in an individual is discrete.e. if a given allele is present, its effects will be seen in the individual.
Individuals carrying two “factors” for most traits are
When the two haploid gametes contain two different alleles of a given gene, the resulting offspring is called
In a heterozygous individual the allele being expressed is
An allele that is present but unexpressed is
. The allelic make up of an individual is referred to as its
The observable outward manifestation of the genes of an individual is referred to as its
What is the name of the cross that involves the mating of a hybrid F1 plant with a homozygous recessive plant for the same trait?
b. true breeding green-seeded plants.
Yellow-seeded plants might be homozygous or heterozygous. We could find out which by crossing these plants with a. true breeding yellow-seeded plants.
b. true breeding green-seeded plants.c.
heterozygous yellow-seeded plants.d. true breeding white-flowered plants.e. true breeding purple-flowered plants
all genes found in an individual are not separable into gametes.
Mendel’s first law encompasses all of the following except
An individual possessing both kinds of alleles of two different traits is called
purple flowers, tall
Let P = purple flowers and p = white, and T = tall plants and t = dwarf. What would be the appearance of a plant with the genotype PpTt?
d. PT, Pt, pT, pt
Difficult ****** Let P = purple flowers and p = white, and T = tall plants and t = dwarf. What combinations of gametes could be produced by a heterozygote for both the traits? a. PpTt onlyb.
Pp, Ttc. P, p, T, td. PT, Pt, pT, pte. infertile, no gametes produced
Let P = purple flowers and p = white, and T = tall plants and t = dwarf. Of the 16 possible gamete combinations in the dihybrid cross, how many would be the phenotype white, tall? a. noneb.
1c. 3d. 9e. 16
they are on different chromosomes.
One of the main reasons genes assort independent of one another is that a. they produce unrelated traits.b.
they produce related traits.c. they are on the same chromosome.d. they are different alleles.e. they are on different chromosomes.
b. multiple alleles.
A single gene has 3 or more alternative forms. These are called a. heterozygotes.
b. multiple alleles.c. epistatic.d. homozygotes.e. multiple zygotes.
Sometimes one gene pair will interact so as to control the expression of a second gene pair in an interaction called a. dominance.b. gene regulation.c.
recessiveness.d. pleiotropy.e. epistasis.
ABO blood group expression is an example of
e. heterozygous purple pea plant and heterozygous purple pea plant
When Mendel crossed two purple-flowered pea plants with each other, he obtained a phenotypic ratio of 3:1 (purple-flowered pea plants to white-flowered pea plants). His results are consistent with which of the following sets of parents? a. homozygous dominant purple pea plant and homozygous recessive white pea plantb. homozygous dominant purple pea plant and heterozygous white pea plantc.
heterozygous purple pea plant and homozygous recessive white pea plantd. heterozygous purple pea plant and homozygous dominant purple pea plante. heterozygous purple pea plant and heterozygous purple pea plant
Many genes, rather than one gene for a characteristic, control some variations in species.
Height and eye colors are two examples of continuous variation in humans. Whereas in pea plants the tall allele is dominant over the short allele, there are no intermediate heights in peas.
Which of the following is the best explanation for the differences described above? a. Humans are more advanced than pea plants; thus, the genetics of peas is much simpler than humans.b. The intermediate size pea plant seeds are aborted within the seedpod and thus will never develop.
c. The intermediate size pea plant seeds have deleterious alleles that prevent them from germinating.d. Many genes, rather than one gene for a characteristic, control some variations in species.e. These variations in humans are affected by lack of dominance in the alleles that control these traits.
b. Since nutrition is necessary for proper development and is a part of the environment, it is a clear case of environmental effect on the phenotype.
. Children born in areas where proper nutrition is not available to them do not always realize their full growth potential.
These children have the genes for normal growth of bones. Which of the following statements can best explain this situation? a. There is a lack of dominance in the alleles for normal bone growth; as a result, the genotype is directly affected.b. Since nutrition is necessary for proper development and is a part of the environment, it is a clear case of environmental effect on the phenotype.
c. Since nutrition is necessary for proper development and is a part of the environment, it is a clear case of environmental effect on the genotype.d. There will always be examples that reflect this condition in human populations because of the continuous variation that exists for this characteristic.e. The children’s parents did not obtain the proper nutrients when they were young and thus were not able to pass on the alleles for normal growth and development.
b. Irene’s genotype is AO, and William’s genotype is BO; thus, Gregory expresses the phenotype of O.
Irene and William are having their first child. Irene knows her blood type is A, but William does not know his blood type. However, William knows that his mother and father were B. Their first child is a boy named Gregory. Gregory has type O blood.
Of course, Irene and William do not understand how this happened. You could explain this to them using which of the following choices? a. Irene’s genotype is AA, and William’s genotype is OO; thus, Gregory expresses the phenotype of O.b. Irene’s genotype is AO, and William’s genotype is BO; thus, Gregory expresses the phenotype of O.c.
Because his parents were both type B, William could not be the father of Gregory.d. Gregory’s blood type will need to be checked after his first month of life if the parents want to know his blood type. It takes about a month for the blood type to develop in a newborn child.e. Since Irene is type A, there had to be a mix-up in the lab report. Gregory should have been type A.
. A person who has lost a large amount of blood but is still alive is found in a wrecked automobile under a highway bridge. Several people are helping the paramedics load the victim into the ambulance. After the ambulance has departed for the hospital, you overhear the following conversation from the persons who helped the paramedics. “I am certain that when that guy gets to the hospital, they will transfuse him with any blood that they have in the blood bank since he has lost so much blood.
” The other person says, “Yeah, I bet you’re right!” Having had a biology course, you know which blood could be safely given to anyone. Select it below. a. Ab. Bc. ABd. O
How many different types of gametes can be formed by plants with a genotype of PpYYrrTt? a.
2b. 4c. 8d. 16
A secretor is a person who secretes their blood type antigens into body fluids and secretions such as saliva. By comparison, a non-secretor does not.
A person’s status as a secretor or non-secretor is independent of blood type. Consider the following inheritance pattern of this trait: secretor x secretor all offspring are secretorsnon-secretor x non-secretor all offspring are non-secretorssecretor x non-secretor all offspring are secretorsF1 generation secretors F2 generation = 75% secretors, 25% non-secretorsRaven – 012 Chapter… The genotypic ratio produced in the F2 generation is a. 3:1.b. 1:2:1.
c. ¾:¼.d. cannot determine from the information provided.
a. 25% will be white and the same 25% will be cross-eyed.
. In white tigers, the absence of fur pigmentation is caused by a recessive allele. This allele also causes the tigers to be cross-eyed. If two tigers heterozygous for this allele mate and produce offspring, what percentage can be expected to be white and/or cross-eyed? a. 25% will be white and the same 25% will be cross-eyed.
b. 25% will be white and 25% will be cross-eyed, but not necessarily the same 25% due to independent assortment.c. 50% will be both white and cross-eyed.d. Because it is a recessive allele, none of the offspring in the F1 generation will be white or cross-eyed.
Let R = red pigment and r = no pigment. In carnations, RR offspring make a lot of red pigment, rr offspring make no pigment and Rr offspring make a small amount of red pigment, thus appearing pink. Pink carnations are therefore an example of a. codominance.b. incomplete dominance.c.
epistatic interaction.d. blending.
d. establish a pedigree.
You can use a Punnet square to do all of the following except a. determine gametic possibilities.
b. predict phenotypic ratio.c. determine genotypic ratio.
d. establish a pedigree.
As a genetic counselor, you are constructing a human pedigree for a particular disease. You note that every generation shows the trait, suggesting that it is a. sex-linked.b.
d. cannot determine from the information provided.
e. they are on different chromosomes
One of the main reasons genes assort independently of one another is that a. they produce unrelated traits.
b. they produce related traits.c. they are on the same chromosome.d. they are different alleles.e.
they are on different chromosomes
. Organisms generally have many more genes that assort independently than the number of chromosomes. This phenomenon is due to
The white eye mutation in Drosophila was shown to be sex-linked and caused by a gene residing on chromosome
c. crossing over.
Genetic exchange between two arms of a chromosome pair is more likely to occur if the distance between the genes is great. It is called a. epistasis.
b. pleiotropy.c. crossing over.d. allelic exchange.e. mutation.
Occasionally, chromosomes fail to separate during meiosis, leading to a condition in which the diploid number is not normal. This phenomenon is called a. epistasis.b.
Humans who have lost even one copy of an autosome are called
The most common condition of trisomy, in which three copies of a chromosome are present instead of the normal two, is of chromosome
c. she developed from a fertilized egg with 3 X chromosomes.
If a human female has two Barr bodies, it is almost certain that a. her father had at least one Barr body.b. her mother also had two Barr bodies.
c. she developed from a fertilized egg with 3 X chromosomes.d. she is actually a male with female characteristics.
e. she is genetically a normal fertile female
c. Turner syndrome.
. A human female with only one X chromosome is said to have a condition called a. Alzheimer’s disease.b. hemophilia.
c. Turner syndrome.d. Klinefelter syndrome.e. Down syndrome.
If some alternative alleles with detrimental effects exist in significant proportions in populations, the condition is called a. pleiotropy.b. a syndrome.c.
epistasis.d. a genetic disorder.e. a genetic imbalance.
Located in the nucleus are
c. a single amino acid substitution.
In sickle cell anemia, the defective hemoglobin differs from the normal hemoglobin by a. the color of the pigment.
b. the size of the molecule.c. a single amino acid substitution.d. the total number of amino acids.e. the type of blood cell it is found in.
a. recessive condition.
Hemophilia is a a. recessive condition.b. dominant condition.c. epistatic condition.d. codominant condition.e. condition that occurs with equal frequency in both sexes
d. Huntington’s disease
. _______________ is a human hereditary disease that is caused by a dominant allele but does not show up in affected individuals until they are in middle age. a. Cystic fibrosisb. Sickle cell anemiac. Tay-Sachs diseased. Huntington’s diseasee. Hemophilia
d. for diagnosis of genetic disorders.
Amniocentesis is a procedure that is normally used a. to reduce the risk of genetic disease.b. for gene therapy.c. to change the sex of the fetus.d. for diagnosis of genetic disorders.e. for nourishing the fetus.
d. Huntington’s disease presents symptoms in humans after many have already reproduced; therefore, they are unaware that they passed on Huntington’s disease.
Huntington’s disease is caused by an autosomal dominant allele. It is a lethal disease, but it persists in the human population. Which of the following statements best describes why? a. Huntington’s disease is sex-linked and every human has at least one X chromosome; thus, the chances are extremely high for this allele to be maintained in the human population.b. Huntington’s disease presents symptoms that resemble cases reflecting a lack of dominance in some individuals; in those cases, the allele is passed on to the offspring.c. While lethal to a parent, Huntington’s disease will not be lethal to the offspring since it can skip a generation.d. Huntington’s disease presents symptoms in humans after many have already reproduced; therefore, they are unaware that they passed on Huntington’s disease.e. Huntington’s disease can be treated in humans that are heterozygous for the condition, but individuals who are homozygous cannot receive treatments; thus, they pass on the alleles to their offspring.
c. In humans the male controls the gender of the offspring, and in birds the female controls the gender.
In humans, the male has an X and Y sex chromosome. The human female has two X chromosomes. In birds, the female has a Z and a W sex chromosome while the male has two Z chromosomes. Which of the following statements is accurate about which parent controls the gender of the offspring? a. In humans and birds the male controls the gender of all the offspring.b. In humans and birds the female controls the gender of all the offspring.c. In humans the male controls the gender of the offspring, and in birds the female controls the gender.d. In humans the female controls the gender of the offspring, and in birds the male controls the gender.e. Control of the gender of any human or bird offspring is related to the environmental conditions at the time of conception.
a. oxygen carrying pigment hemoglobin.
Sickle cell anemia is caused by a defect in the a. oxygen carrying pigment hemoglobin.b. protein makeup in the liver.c. sticky sides of the red blood cells.d. allele for the production of mucus in the lungs.
d. identify the chromosome on which a gene is located.
A test cross can be used to do all of the following except a. determine whether an individual that displays a dominant phenotype is homozygous for the trait.b. determine whether an individual that displays a dominant phenotype is heterozygous for the trait.c. gather genotype information from phenotype information.d. identify the chromosome on which a gene is located.
a. be female because they do not have a Y chromosome
. In humans, if a non-disjunction event led to an individual with a genotype of XO, they would a. be female because they do not have a Y chromosome.b. be male because they only have one X chromosome.c. display both male and female characteristics.d. not survive.
b. be male because they have a Y chromosome.
In humans, if a non-disjunction event led to an individual with a genotype of XXY, they would a. be female because they have two X chromosomes.b. be male because they have a Y chromosome.c. display both male and female characteristics.d. not survive.
Genetic differences between individuals in a population are called a. markers.b. alleles.c. polymorphisms.d. genetic disorders.
a. develop as a female.
If a XY individual had a deletion of the SYR gene, they would a. develop as a female.b. have both male and female characteristics.c. have ambiguous genitalia.d. develop as a male.
c. XY, female.
If an XY individual had a genetic disorder in which they were insensitive to androgens, their genotype and phenotype would be a. XX, female.b. XX, male.c. XY, female.d. XY, male.
c. both sons and daughters
. Which offspring will inherit all their mitochondria DNA from their mother and none from their father? a. daughtersb. sonsc. both sons and daughtersd. Mitochondria DNA is inherited from both parents.
Nondisjunction of autosomes can lead to all of the following except a. aneuploidy.b. monosomy.c. trisomy.d. euploidy.
c. a three-point cross.
If you needed to order genes on a chromosome, you would perform a. a test cross.b. a two-point cross.c. a three-point cross.d. a SNP test.
c. chorionic villi sampling.
A 39-year-old woman is in her sixth week of pregnancy. Due to her advanced maternal age, she is at high risk for having a baby with Down’s syndrome. She would like to find out as early as possible whether or not her baby has Down’s syndrome. Her doctor suggests a. amniocentesis.b. genetic counseling.c. chorionic villi sampling.d. a pedigree analysis.
c. As genetic distance increases, the recombination frequency first increases in a linear fashion, but then levels off to a frequency of 0.5.
What is the relationship between recombination frequency and true genetic distance on a chromosome? a. As genetic distance increases, the recombination frequency increases in a linear fashion.b. As genetic distance increases, the recombination frequency increases, but never in a linear fashion.c. As genetic distance increases, the recombination frequency first increases in a linear fashion, but then levels off to a frequency of 0.5.d. As genetic distance increases, the recombination frequency first increases, but then decreases.
a. single nucleotide polymorphisms (SNPs)
You are a forensic technician working on a DNA sample obtained from a crime scene. Your job is to compare the unknown DNA sample with known DNA samples collected from five different suspects. Preliminary analysis using only a few DNA markers revealed that the unknown sample could possibly match two of the suspects. After consulting the case file, you find out that these two suspects are brothers (but not twins). You realize that you will have to do a more detailed analysis on the samples so that you can distinguish between the brothers and determine which brothers’ DNA matches the unknown sample. Raven – 013 Chapter… 120. Which of the following will help you distinguish between the two final suspects? a. single nucleotide polymorphisms (SNPs)b. human genetic mapc. linkage datad. anonymous markers
b. The brothers share the same mitochondrial DNA.
Why can’t you use mitochondrial DNA to distinguish between these two suspects? a. The sequence of mitochondrial DNA has not yet been determined.b. The brothers share the same mitochondrial DNA.c. There are no molecular techniques available that allow one to analyze mitochondrial DNA.d. Because mitochondrial DNA is inherited in a paternal pattern.
d. Heterozygous individuals have some other advantage over individuals with two wild type alleles
Over time, natural selection eliminates individuals with detrimental phenotypes from a population. However, there are several examples in the human population in which harmful genetic polymorphisms are maintained. Why? a. Individuals with two wild type alleles have advantages over individuals carrying the harmful allele.b. Individuals with two harmful alleles have advantages over individuals carrying one copy of the harmful allele.c. Homozygous individuals have some other advantage over individuals with two wild type alleles.d. Heterozygous individuals have some other advantage over individuals with two wild type alleles
Bacteria divide by binary _______, in which the cell divides into two nearly equal halves.
DNA coiled around histone proteins forms a complex known as a _________.
Most eukaryotic cells go through a repeating process of growth and division referred to as the cell ______.
The accommodation of the very long DNA fiber into a limited space of the nucleus is achieved by coiling around beads of histones into repeating subunits. These subunits of chromosomes are given the name __________.
Each chromosome has a region called the _________ somewhere between the two ends where attachment of protein rays occurs.
6. Interphase 7 condensation 8 Metaphase 9 anaphase 10 telophase
6. _________ is that portion of the cell cycle in which the chromosomes are invisible under the light microscope because they are not yet condensed.7. Prophase is the first stage of mitosis characterized by the _________ of the chromosomes.8. __________ is the stage of mitosis characterized by the alignment of the chromosomes in a ring along the inner circumference of the cell.9. The stage of mitosis characterized by the physical separation of sister chromatids is called __________.10. The last stage of mitosis is characterized by the disassembly of spindle apparatus, the reestablishment of the nuclear membrane, and the decondensation of the chromosomes into invisible threads. This stage is known as _________.
cyclins 12 FtsZ 13 p53
11. The progress of mitosis is regulated by ______ and their dependent kinases.12. Binary fission in prokaryotes concludes with the accumulation of _______ protein at the midpoint of the cell which facilitates septum formation.13. Normally _____ functions in the cell to stop cell division if the cell has experienced extensive DNA damage.
Eukaryotic chromosomes are composed of a complex of 60% protein and 40% DNA. The name of this chemical complex isA. a histone complexB. chromatinC. a histamine complexD. a chromatidE. a centromere
If a eukaryotic cell has a single set of chromosomes, it is calledA. haploidB. diploidC. polypoid
C. a karyotype
The physical map of the array of chromosomes is calledA. ecotypeB. a haplotypeC. a karyotypeD. a phenotypeE. a genotype
By the end of this phase of mitosis, the centromere joining each pair of sister chromatids is attached by microtubules to opposite poles of the spindle apparatus. This phase is calledA. prophaseB. metaphaseC. anaphaseD. telophaseE. interphase
The physical distribution of cytoplasmic material into the two daughter cells is calledA. DNA replicationB. mitosisC. cytokinesisD. binary fissionE. syngamy
A. growth, reproduction
Which of the following cell functions are maintained by cell division?
B. single, circular, uncoated, double stranded DNA molecule
The bacterial genome exist as aA. single, circular, protein-coated, double stranded DNA moleculeB. single, circular, uncoated, double stranded DNA moleculeC. single, circular, uncoated, double stranded RNA moleculeD. single, linear, uncoated, double stranded DNA moleculeE. many, circular, uncoated, double stranded DNA molecules
E. plasma membrane pinches inward constricting the cell
The division of a bacterial cell occurs as theA. cell wall develops cracks around the equator of the cellB. chromosomes are pulled toward the ends of the cellC. cytoplasm forms a cell plate around the middle of the cellD. microfilaments and microtubules constrict the cytoplasmE. plasma membrane pinches inward constricting the cell
The number of chromosomes characteristic of eukaryotes, in general,A. can usually be determined without the use of a microscopeB. can usually be predicted from the size of the organismC. change as the organisms grow and ageD. vary considerably from 2 to l00s in different speciesE. vary depending on the type of the cell in the same organism
Some of the portions of the chromatin are permanently condensed so that their DNA is never expressed. All of these portions stain very intensely and are given a common name ofA. DNA dark bandsB. euchromatinC. heterochromatinD. genomeE. haploid DNA
In the human, the body cells (non-sex cells) contain two sets of chromosomes totalingA. 2B. 22C. 44D. 46E. 23
B. homologous chromosomes
The two copies of each chromosome in body cells are calledA. chromatidsB. homologous chromosomesC. sister chromosomesD. daughter chromosomesE. genes
A. sister chromatids
Before cell division of the body cells, each homologue replicates into two parts. These parts are connected by a centromere and are calledA. sister chromatidsB. daughter chromatidsC. sister chromosomesD. daughter chromosomesE. genes
C. the nucleolus to disappear
In prophase, ribosomal RNA synthesis stops when the chromosomes condense, and this makesA. chromosomes longerB. the nuclear envelope to show upC. the nucleolus to disappearD. chromosomes to line up at the equatorE. staining very light