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LIFE 102 CSU Erik Arthun With 40
Questions With Answers
In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange fur color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of an orange female and a black male?
A) Orange females; black males B) Tortoiseshell females; orange males C) Tortoiseshell females; black males D) Black females; orange males - โ โ Tortoiseshell females; orange males Kirsten suffers from colorblindness, a recessive X-linked disorder. She has a brother, Erik, who is NOT affected. What do we know about their parents?
A) Both parents are colorblind B) Both parents are carriers (they are not colorblind) C) The mother is a carrier, the father is colorblind D) The father is a carrier, the mother is not - โ โ The mother is a carrier, the father is colorblind
Allele pairs are most likely to assort independently of one another when __________.
A) They are sex-linked B) They control related traits C) They control unrelated traits D) They are on different chromosomes E) They are on the same chromosome - โ โ They are on different chromosomes You inherited two copies of chromosome #15 from your parents (one from your mother, and one from your father). We refer to these paired chromosomes as "homologous chromosomes". Which of the following is true of homologous chromosomes?
A) They are identical to one another B) They align on the metaphase plate during meiosis II C) They carry the same alleles D) They contain genes for the same traits - โ โ They contain genes for the same traits All animal cells are diploid except __________.
A) Nerve cells
A) Haploid, and the chromosomes are each composed of a single chromatid B) Diploid, and the chromosomes are each composed of 2 chromatids C) Haploid, and the chromosomes are each composed of 2 chromatids D) Diploid, and the chromosomes are each composed of a single chromatid - โ โ Haploid, and the chromosomes are each composed of 2 chromatids The four phases of meiosis II are essentially identical to the phases of mitosis. A) This is true B) This is false - โ โ This is true Which best describes the process of independent assortment?
A) During synapsis, homologous chromosomes pair independently of each other. B) Crossing over along one pair of chromosomes is independent of crossing over along the other pairs. C) During synapsis, chromosomes pair up at random. D) Segregation of chromosomes during meiosis I is independent of their segregation during meiosis II. E) The way one pair of homologous chromosomes lines up along the metaphase plate does not affect how any other pair lines up. - โ โ
The way one pair of homologous chromosomes lines up along the metaphase plate does not affect how any other pair lines up. From an evolutionary perspective, what is the main advantage of sexual reproduction?
A) It creates offspring that are genetically the same as the parents, which is advantageous in a changing environment B) It creates offspring that are genetically diverse, which is advantageous in a changing environment C) It creates offspring that are genetically diverse, which is advantageous in a constant environment D) It creates offspring that are genetically the same as the parents, which is advantageous in a constant environment - โ โ It creates offspring that are genetically diverse, which is advantageous in a changing environment Genes often exist in multiple versions, such as the different types of genes in pea plants that cause their flowers to appear either purple or white. Versions of a gene are termed _________________.
A) Kinetochores B) Centromeres C) Telomeres D) Alleles
D) Parental traits that were not observed in the F1 generation reappeared in the F2 generation E) The dominant phenotypes were visible in the F2 generation, but not in the F1 generation - โ โ The dominant phenotypes were visible in the F2 generation, but not in the F1 generation If fertilization involves two gametes that contain different alleles of a given gene, the resulting offspring is __________.
A) Polygenic B) Homozygous C) Heterozygous D) Dihybrid E) Haploid - โ โ Heterozygous Sometimes, when Mendel crossed two pea plants with each other, he obtained a phenotypic ratio of 3:1 purple-flowered pea plants to white- flowered pea plants. These results are consistent with which set of parents?
A) heterozygous purple pea plant and homozygous white pea plant B) heterozygous purple pea plant and heterozygous purple pea plant C) heterozygous purple pea plant and homozygous purple pea plant
D) homozygous purple pea plant and homozygous white pea plant - โ โ heterozygous purple pea plant and heterozygous purple pea plant *****The following is a linkage map of four genes on a chromosome: Between which 2 genes would you expect the lowest frequency of recombination?
A) W and E B) A and G C) A and W D) A and E E) E and G - โ โ W and E In 95% of cases of Down syndrome, there is one extra chromosome (number 21) in every cell. This aneuploid condition is most likely the result of __________.
A) failure of the cytoplasm to divide at the end of meiosis II B) failure of 1 homologous pair to segregate during meiosis C) failure of 2 homologous pairs to segregate during meiosis D) failure of the chromosomes to assort independently during meiosis E) failure to suppress DNA replication between meiosis I and meiosis II - โ โ failure of 1 homologous pair to segregate during meiosis
C) 10
D) 0 - โ โ 20
In human and many other eukaryotic species' cells, the nuclear membrane has to disappear to permit _______________.
A) Cytokinesis B) The disassembly of the spindle apparatus C) The attachment of microtubules to kinetochores D) The splitting of the centrosomes - โ โ The attachment of microtubules to kinetochores If a cell has 32 chromosomes prior to S and undergoes mitosis followed by cytokinesis, each new daughter cell will have how many chromosomes?
A) 32 B) 64 C) 16 D) 8 - โ โ 32 Through a microscope, you can see a cell plate beginning to develop across the middle of a cell, and nuclei forming on either side of the cell plate. This cell is most likely ________________.
A) An animal cell in the process of cytokinesis B) A plant cell in metaphase C) A plant cell in the process of cytokinesis D) An animal cell in the S phase of the cell cycle - โ โ A plant cell in the process of cytokinesis Some cells have several nuclei per cell. How could such multinucleated cells be explained?
A) The cell underwent repeated mitosis with simultaneous cytokinesis. B) The cell underwent repeated mitosis, but cytokinesis did not occur. C) The cell underwent repeated cytokinesis, but no mitosis. D) The cell had multiple S phases before it entered mitosis. - โ โ The cell underwent repeated mitosis, but cytokinesis did not occur. Starting with a single fertilized egg, a series of 5 cell divisions would produce an early embryo with how many cells?
A) 128 B) 64 C) 8 D) 16 E) 32 - โ โ 32
B) Albino and black are codominant C) Albino is recessive; black is codominant D) Albino is recessive; black is completely dominant - โ โ Albino is recessive; black is completely dominant In cattle, "roan" coat color (mixed red & white hairs) occurs in the heterozygous (Rr) offspring of red (RR) and white (rr) homozygotes. Which of the following crosses would produce offspring in the ratio of 1:1 (roan:white)?
A) White x Red B) Red x Roan C) Red x White D) Roan x Roan E) White x Roan - โ โ White x Roan Humans with both the IA and IB alleles for blood type have both A and B carbohydrates on their red blood cells, and are blood type "AB". This is an example of ___________________.
A) Incomplete dominance B) Codominance C) Epistasis D) Polygenic inheritance
E) Pleiotropy - โ โ Pleiotropy Height is a trait that shows continuous variation in humans. In pea plants, on the other hand, the tall allele is dominant over the short allele and there are no intermediate heights. What is the best explanation for this difference?
A) Height is a polygenic trait in pea plants. B) The alleles that control height in humans are pleiotropic. C) The alleles that control height in pea plants are epistatic. D) The alleles that control height in pea plants are pleiotropic. E) Height is a polygenic trait in humans. - โ โ Height is a polygenic trait in humans. Gene S controls the sharpness of spines in a type of cactus. Cactuses with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cactuses have dull spines. At the same time, a second gene, N, determines whether cactuses even have spines. Homozygous recessive nn cactuses have no spines at all. The relationship between genes S and N is an example of:
A) Complete dominance B) Incomplete dominance C) Epistasis D) Codominance
B) Dominant C) Located on an autosome D) Located on the X chromosome E) Codominant - โ โ Located on the X chromosome Males are more-often affected by sex-linked traits than females because:
A) Male hormones (such as testosterone) often alter the effects of mutations on the X chromosome B) X chromosomes in males generally have more mutations than X chromosomes in females C) Females have only one copy of the Y chromosome D) Males have only one copy of the X chromosome E) Female hormones (such as estrogen) often compensate for the effects of mutations on the X chromosome - โ โ Males have only one copy of the X chromosome Of the 23 pairs of human chromosomes, 22 pairs are homologous and are found in both males and females. These are called __________.
A) Alleles B) Autosomes C) Somatic chromosomes
D) Bivalent chromosomes E) Recombinant chromosomes - โ โ Autosomes A male who carries one particular allele of an X-linked gene will pass it on to ________.
A) All of his daughters B) Half of his daughters C) All of his children D) All of his sons - โ โ All of his daughters
