Bio: Study Set Lectures: 19-26
In some organisms, mitosis occurs without cytokinesis occurring. This will result in A) cells lacking nuclei B) cell cycles lacking an S phase C) cells that are unusually small D) cells with more than one nucleus E) destruction of chromosomes
The correct answer is D
Homologous chromosomes move toward opposite poles of a dividing cell during A) meiosis II B) meiosis I C) mitosis D) fertilization
The correct answer is B
If a gene has a recessive lethal allelic situation, crossing two heterozgotes should result in an offspring phenotypic ratio of A) 1:1 B) 2:1 C) 0:1 D) 3:1
The correct answer is B
A human cell containing 22 autosomes and a Y chromosome is A) a sperm cell B) a somatic cell of a female C) a zygote D) an ovum E) a somatic cell of a male
The correct answer is A
A hypothetical flowering plant produces blue, light blue, and white flowers. To determine the inheritance pattern, the following crosses were conducted with the results indicated: blue x blue ⟶ all blue white x white ⟶ all white blue x white ⟶ all light blue What type of inheritance pattern does this represent? A) incomplete dominance B) simple Mendelian C) X-linked D) codominance E) pleiotropy
The correct answer is A
A recessive sex-linked gene in humans leads to a loss of sweat glands. A woman heterozygous for this will A) have patches of skin with and without sweat glands B) have an excess of sweat glands C) have no sweat glands D) have normal sweat glands
The correct answer is A
An individual that has two different alleles of a particular gene is said to be A) heterozygous B) dihybrid C) hemizygous D) homozygous E) recessive
The correct answer is A
Binary fission in prokaryotes does not require the: A) assembly of the nuclear envelope B) elongation of the cell C) separation of daughter cells by septum formation D) replication of DNA
The correct answer is A
In a cross of AaBbcc X AaBbCc, what is the probability of obtaining an individual with the genotype AABbCc? A) 1/16 B) 3/16 C) 3/64 D) 1/64
The correct answer is A
The genes for the traits that Mendel worked with are either located on different chromosomes or so far apart on the same chromosome that crossing over almost always occurs between them. How did this circumstance help Mendel recognize the principle of independent assortment? A) otherwise, his dihybrid crosses would not have produced a 9:3:3:1 ratio of F2 phenotypes B) the occurrence of individuals with unexpected phenotypes led him to the discovery of recombination C) it led him to the realization that the behavior of chromosomes during meiosis explained his results D) it meant that the alleles involved were either dominant or recessive, which gave 3:1 ratios in the F1 generation
The correct answer is A
The influence of neighboring cells on the regulation of cell division is known as A) social control B) proximity regulation C) neighbor monitoring D) perimeter dominance
The correct answer is A
What happens if the sister chromatids of one chromosome fail to separate during karyokinesis? A) one daughter cell receives too few chromosomes; the other receives a replicated chromosome B) the kinetochore microtubules do not function properly C) the polar microtubules do not function properly D) one daughter cell receives all the chromosomes; the other receives none
The correct answer is A
What major events occur during anaphase of mitosis? A) sister chromatids separate, and the spindle poles are pushed apart B) the chromosomes end up at opposite ends of the cell and two nuclear envelopes form around them C) chromosomes replicate, so each chromosome consists of two identical sister chromatids D) chromosomes condense and the nuclear envelope disappears
The correct answer is A
Which of the following is the strongest evidence that a trait might be influenced by polygenic inheritance? A) the trait shows quantitative variation B) F1 offspring by parents with different phenotypes have the dominant phenotype C) F1 offspring by parents with different phenotypes have an intermediate phenotype D) the trait shows qualitative (discrete) variation
The correct answer is A
Why is the white-eye phenotype always observed in Drosophila males carrying the white-eye allele? A) because the allele is located on the X chromosome and males only have one X B) because the trait is recessive C) because the trait is dominant D) because the allele is located on the Y chromosome and only males have Y chromosomes
The correct answer is A
Based on Mendel's experimental crosses, what is the expected F2 phenotypic ratio of a monohybrid (one trait) cross? A) 9:3:3:1 B) 3:1 C) 2:1 D) 4:1 E) 1:2:1
The correct answer is B
Calico coat pattern in cats is the result of A) maternal inheritance B) X inactivation C) epistasis D) genomic imprinting E) organelle heredity
The correct answer is B
Cancer cells are said to be metastatic when they A) invade healthy tissue B) migrate to other parts of the body C) begin to divide uncontrollably D) cause mutations in other healthy cells
The correct answer is B
During the process of spermatogenesis, a nondisjunction event that occurs during the second division would be A) the same outcome as the first division as only two products would be aneuploid B) better than the first division because only two of the four meiotic products would be aneuploid C) the same outcome as the first division with all four products aneuploid D) worse than the first division because all four meiotic products would be aneuploid
The correct answer is B
In a test cross, what do you do with an organism with dominant phenotype of unknown genotype? A) cross it with a known dominant true breeder B) cross it with a organism with the recessive phenotype C) allow it to self-fertilize D) cross it with another unknown dominant phenotype
The correct answer is B
Japanese four o'clocks that are red and tall are crossed to white, short ones, producing an F1 that is pink and tall. If these genes assort independently, and the F1 is self-crossed, what would you predict for the ratio of F2 phenotypes? A) 3 red tall:1 white short B) 3 red tall:6 pink tall:3 white tall:1 red short:2 pink short:1 white short C) 1 red tall:2 pink short:1 white short D) 3 pink tall:6 red tall:3 white tall:1 pink short:2 red short:1 white short
The correct answer is B
The F1 generation of the monohybrid cross purple (PP) X white (pp) flower pea plants should A) all have white flowers B) all have purple flowers C) all have light purple or a blended appearance D) have ¾ purple flowers and ¼ white flowers
The correct answer is B
The decline of MPF activity at the end of mitosis is caused by A) the destruction of the protein kinase Cdk B) the degradation of cyclin C) decreased synthesis of Cdk D) the accumulation of cyclin E) synthesis of DNA
The correct answer is B
Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to A) myosin denaturation and inhibition of cleavage furrow formation B) disruption of mitotic spindle formation C) inhibition of regulatory protein phosphorylation D) suppression of cyclin production E) inhibition of DNA synthesis
The correct answer is B
What is a tumor suppressor? A) a gene that accelerates the cell cycle and leads to uncontrolled cell growth B) a gene associated with tumor formation when its product does not function C) a gene associated with tumor formation when its product functions normally D) a gene that codes for a transcription factor involved in tumor formation
The correct answer is B
What step in the cell cycle represents an irreversible commitment to division? A) there are no irreversible commitments B) the G1/S checkpoint C) the S/G2 checkpoint D) the metaphase checkpoint
The correct answer is B
Which of the following best describes a recessive trait A) the least common trait in a population B) a trait that is masked by the presence of a dominant trait C) a trait found on only one chromosome D) a trait resulting from the absence of a protein
The correct answer is B
Which of the following does not contribute to genetic diversity? A) independent assortment B) metaphase of meiosis II C) recombination (crossing over) D) chromosome contributions from two parental sources
The correct answer is B
Which of the following is a reason for mitotic cell division? A) growth B) all of these are correct C) asexual reproduction D) repair and replacement
The correct answer is B
Which statement about the daughter cells following mitosis and cytokinesis is correct? A) only one of the two daughter cells is genetically identical with the parent cell B) they are genetically identical with each other and with the parent cell C) they are genetically different from each other and from the parent cell D) they are genetically identical with each other but different from the parent cell
The correct answer is B
A replicated chromosome is composed of: A) one chromatid with a centromere B) four sister chromatids held together at the centromere C) two sister chromatids held together at the centromere D) four homologous chromosomes held together at the centromere E) two homologous chromosomes held together at the centromere
The correct answer is C
A woman is heterozygous for an X-linked trait, hemophilia A. If she has a child with a man without hemophilia A, what is the probability that the child will be a male and also have hemophilia A? (Note: The child could be a male or female.) A) 100% B) 75% C) 25% D) 50% E) 0%
The correct answer is C
An organism's ___ is/are determined by its ____ A) genes; alleles B) genotype; phenotype C) phenotype; genotype D) alleles; phenotype
The correct answer is C
Apoptosis is the process of A) cell signaling B) signal amplification C) programmed cell death D) cell migration E) signal transduction
The correct answer is C
As the distance between the loci of two genes increases, the likelihood of "breaking linkage" between these two genes A) decreases B) linkage between two genes cannot be broken regardless of distance C) increases D) stays the same
The correct answer is C
Dogs have 78 chromosomes in their diploid cells. If a diploid dog cell enters meiosis, how many chromosomes and chromatids will be present in each daughter cell at the end of meiosis I? A) 78 chromosomes and 156 chromatids B) 78 chromosomes and 78 chromatids C) 39 chromosomes and 78 chromatids D) 39 chromosomes and 39 chromatids
The correct answer is C
During anaphase I A) all the chromosomes align independently at the middle of the cell B) homologous chromosomes move to opposite poles C) homologous chromosomes align at the middle of the cell D) sister chromatids separate and move to the poles
The correct answer is C
How does DNA replication differ between mitosis and meiosis? A) during mitosis, there is only one round of replication every other division B) during meiosis, only the maternal chromosomes are replicated C) DNA replication is exactly the same in mitosis and meiosis D) DNA replication takes less time in meiosis because the cells are haploid
The correct answer is C
If an organism is described as being a "true breeder" for a particular trait, what can the genotype of that organism be assumed to be? A) dominant B) recessive C) homozygous D) heterozygous
The correct answer is C
In Drosophila fruit flies, the allele for red eye color is considered to be the wild type allele. What does this mean? A) this allele alternates between being dominant and being recessive B) this is the dominant allele for this gene C) this is the most common allele for this gene in the population D) This allele is only found in domesticated flies
The correct answer is C
In an organism's genome, autosomes are A) chromosomes that are involved in sex determination B) the chromosomes that differ between the sexes C) all of the chromosomes other than the sex chromosomes D) only inherited from the mother (maternal inheritance)
The correct answer is C
In the spindle, the ______ ends of the kinetochore microtubules are embedded in the kinetochore, and the ______ ends are at the spindle pole. A) plus; plus B) minus; plus C) plus; minus D) minus; minus E) none of these is correct
The correct answer is C
In which phase of the cell cycle are chromosomes replicated? A) M phase B) G2 phase C) S phase D) none of these E) G1 phase
The correct answer is C
The alleles found in haploid organisms cannot be dominant or recessive. Why? A) because only one allele is present, alleles in haploid organisms are always recessive B) alleles in haploid individuals are transmitted like mitochondrial DNA or chloroplast DNA C) dominance and recessiveness describe which allele is expressed in the phenotype when different alleles occur in the same individual D) most haploid individuals are bacteria, and bacterial genetics is completely different from eukaryotic genetics
The correct answer is C
The immediate product of fertilization is called a(n) A) ovum B) gamete C) zygote D) parthogenote
The correct answer is C
What proportion of the offspring of a cross between a male with an X-linked recessive trait and a female carrier for that trait would also have the trait? A) none of these is correct B) 50% of the females only C) half of all children, regardless of their gender D) all the males E) 50% of the males only
The correct answer is C
When homozygous, a particular allele of a locus in rats causes abnormalities of the cartilage throughout the body, an enlarged heart, slow development, and death. This is an example of A) polygenic inheritance B) dosage compensation C) pleiotropy D) codominace E) epistasis
The correct answer is C
Which of Mendel's laws/principles cannot be observed in a monohybrid (one trait) cross? A) all of the above can be observed in a monohybrid cross B) dominance and recessiveness C) independent assortment D) segregation
The correct answer is C
Which of the following are genetically identical? A) four cells resulting from meiosis I followed by meiosis II B) two cells resulting from meiosis II C) two cells resulting from a mitotic division D) two cells resulting from meiosis I E) all of these answers are correct
The correct answer is C
Which of the following statements concerning linkage is not true? A) traits determined by genes located on the same chromosome are likely to be inherited together B) the probability of crossing over depends on the distance between the genes C) a crossover is more likely to occur in a region between two genes that are close together than in a region between two genes that are farther apart D) genes that tend to be transmitted together are physically located on the same chromosome E) crossing over between homologous chromosomes can create new allele combinations
The correct answer is C
You would expect to find a synaptonemal complex in a cell at A) meiotic prophase II B) meiotic anaphase I C) meiotic prophase I D) meiotic anaphase II E) mitotic prophase
The correct answer is C
______ is a prefix that refers to cancer A) ankylo B) lethalo C) onco D) meta
The correct answer is C
A gene that affects more than one phenotypic trait is said to be A) dominant B) heterozygous C) dihybrid D) pleiotropic E) wild type
The correct answer is D
A man and a woman are both heterozygous for the recessive allele that causes cystic fibrosis. What is the probability that their first 2 offspring will have the disorder? (This means the first child would have the disease AND the second child would have it) A) 1/32 B) 1/4 C) 0 D) 1/16 E) 1
The correct answer is D
A student is looking at cells under the microscope. The cells are from an organism that has a diploid number of 14. In one particular case, the cell has seven replicated chromosomes (sister chromatids) aligned at the metaphase plate of the cell. Which of the following statements accurately describes this particular cell? A) the cell is in metaphase of mitosis B) the cell is in metaphase of meiosis I C) all of these answers are correct D) the cell is in metaphase of meiosis II
The correct answer is D
Crossing over usually contributes to genetic variation by exchanging chromosomal segments between A) chromatids of non homologues B) autosomes and sex chromosomes C) nonhomologous loci of the genome D) nonsister chromatids of homologues E) sister chromatids of a chromosome
The correct answer is D
Cyclin-dependent kinases (Cdks) are regulated by A) bipolar attachment of chromosomes to the spindle B) all of these are correct C) DNA synthesis D) the periodic increase and destruction of cyclins
The correct answer is D
Down syndrome is the result of trisomy for chromosome 21. Why is this trisomy viable and trisomy for most other chromosomes is not? A) chromosome 21 is a large chromosome and excess genetic material is less harmful B) chromosome 21 behaves differently in meiosis I than the other chromosomes C) chromosome 21 is less prone to nondisjunction than other chromosomes D) chromosome 21 is a small chromosome with few genes so this does less to disrupt the genome
The correct answer is D
If a father with type A blood marries a woman with type O blood and they have a child with type O blood as well. What does this tell you about the father? A) the father is homozygous for the O allele B) nothing, there is not enough information provided C) the father is homozygous for the A allele D) the father is heterozygous
The correct answer is D
If the DNA content (# of chromosomes) of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be A) 2x B) 4x C) 0.5x D) x E) 0.25x
The correct answer is D
If two chromosomes are homologous they: A) carry the same types of genes B) may carry different versions of the same gene C) look similar under the microscope D) all of these answers are correct E) have very similar DNA sequences
The correct answer is D
One difference between cancer cells and normal cells is that cancer cells A) cannot function properly because they are affected by density-dependent inhibition B) are unable to synthesize DNA C) are arrested at the S phase of the cell cycle D) continue to divide even when they are tightly packed together
The correct answer is D
The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B? A) DNA synthesis B) spindle formation C) spindle attachment to kinetochores D) cleavage furrow formation and cytokinesis E) cell elongation during anaphase
The correct answer is D
The molecular tether that links sister chromatids together of a duplicated chromosome to each other is A) condensin B) actin C) myosin D) cohesin E) actomyosin
The correct answer is D
Through a microscope, you can see a cell plate beginning to develop across the middle of the cell and nuclei re-forming on either side of the cell plate. This cell is most likely A) a bacterial cell dividing B) an animal cell in the process of cytokinesis C) an animal cell in the S phase of the cell cycle D) a plant cell in the process of cytokinesis E) a plant cell in metaphase
The correct answer is D
When you cross true-breeding tall and short tobacco plants, you get an F1 that is intermediate in height. When this F1 is self-crossed, it yields an F2 with a continuous distribution of heights. What is the best explanation for these data? A)height is determined by a single gene with many alleles B) height is determined by a single gene with incomplete dominance C) height is determined by epistatic genes D) height is determined by the additive effects of many genes
The correct answer is D
Which of the following does not occur during mitosis A) separation of sister chromatids B) spindle formation C) condensation of chromosomes D) replication of DNA
The correct answer is D
Which of the following genotypes due to nondisjunction of sex chromosomes is lethal? A) XXY B) XO C) XXX D) OY
The correct answer is D
A eukaryotic cell lacking telomerase would A) be unable to identify and correct mismatched nucleotides B) be unable to take up DNA from the surrounding solution C) have a greater potential to become cancerous D) be unable to connect Okazaki fragments E) experience a gradual reduction of chromosome length with each replication cycle
The correct answer is E
If we continued to follow the cell lineage from the previous question, then the DNA content at metaphase of meiosis II would be A) 4x B) 2x C) 0.25x D) x E) 0.5x
The correct answer is E