Topic 1-3 quiz

Discuss TWO examples of meiotic errors and their effects on offspring.

- Nondisjunction may occur, where chromosomes fail to separate

Describe THREE differences between mitosis and meiosis.

-Meiosis dives twice and creates four daughter cells, while mitosis divides once and only creates two - Mitosis creates two identical daughter cells, and meiosis creates four unique daughter cells by crossing chromosomes - Meiosis divides gametic cells and mitosis divides somatic cells

Eye color in a fly is influenced by one gene with two alleles: a dominant allele that results in red eyes and a recessive allele that results in sepia eyes.A red-eyed female from a true-breeding population is mated with a sepia-eyed male. The F1 offspring are all red eyed. The F1 flies are allowed to interbreed, producing the following in the F2 generation. Females: 40 red eyes; 13 sepia eyes Males: 39 red eyes; 11 sepia eyes Which of the following best describes the likely mode of inheritance for the eye-color gene?* A.The eye-color gene is likely autosomal because males and females have similar phenotype ratios. B.The eye-color gene is likely autosomal because more females have sepia C. eyes than males do. C.The eye-color gene is likely sex-linked because the males and females have similar phenotype ratios. D. The eye-color gene is likely sex-linked because the males and females display both phenotypes.

A

In dogs, one pair of alleles determines coat color (dark and albino). Another pair of alleles determines hair length (short and long). Thus, each gamete will contain one of the coat-color alleles, C or c and one of the hair-length alleles, B or b. In repeated crosses of a specific dark, short-haired dog with an albino, long-haired dog, all the offspring were dark with short hair, as shown in cross I. However, in subsequent crosses of another dark, short-haired dog with a dark, long-haired dog, the ratios shown in cross II below were obtained.In cross II, the genotype of the dark, short-haired parent is:* A.CcBb B.ccbb C.CCBB D.CCbb E. ccBB

A

In dogs, one pair of alleles determines coat color (dark and albino). Another pair of alleles determines hair length (short and long). Thus, each gamete will contain one of the coat-color alleles, C or c and one of the hair-length alleles, B or b. In repeated crosses of a specific dark, short-haired dog with an albino, long-haired dog, all the offspring were dark with short hair, as shown in cross I. However, in subsequent crosses of another dark, short-haired dog with a dark, long-haired dog, the ratios shown in cross II below were obtained.Which of the following correctly describes the relationship of the dark-coat-color allele to the albino condition?* A.It is dominant. B.It is recessive. C. It is codominant. D.It is a polygenic inheritance pattern. E. The alleles are linked.

A

In fruit flies of the genus Drosophila, the allele for vestigial wings is recessive to the allele for round wings, and the allele for brown eye color is recessive to the allele for red eye color. A scientist crossed flies that are heterozygous for both traits and determined the number of offspring with each combination of phenotypes. The scientist performed a chi-square analysis to determine if the data are consistent with the expectations for independent assortment. The chi-square calculated value for the experiment was 6.03.Based on the chi-square calculated value, which of the following statements is most accurate?* The chi-square calculated value is greater than the chi-square critical value; therefore the null hypothesis should be rejected. The chi-square calculated value is greater than the chi-square critical value; therefore the null hypothesis should not be rejected. The chi-square calculated value is less t

A

Table I shows the results of breeding experiments to examine the inheritance of flower color (purple versus white) and pod shape (inflated versus constricted). For the crosses recorded in Table I, true-breeding parents were crossed to produce F1offspring, which were then test crossed to homozygous recessive individuals. Table II shows the results of computer simulated crosses to model the inheritance of leaf shape (broad versus narrow) and flower color (purple versus white).Based on the data in Table I, which of the following best explains why there are no individuals with constricted pods in the F1generation?* A.Inflated pod shape is dominant to constricted pod shape. B. The inflated-pod offspring in the F1generation are homozygous. C. Constricted pod shape typically arises from a new mutation in the F1generation. D. The constricted-pod offspring are carriers for the inflated pod shape allele.

A

A blue-flowered African violet of unknown ancestry self-pollinated and produced 50 seeds. These seeds germinate and grow into flowering plants. Of these plants, 36 produce blue flowers and 14 produce pink flowers. What is the best explanation for the pink-flowered offspring??* a. Blue flowers are incompletely dominant to pink flowers. B.Pink flower color is a trait recessive to blue flower color. C. Pink flower color is the result of somatic mutations in the flower color gene. D. A previous generation of the blue-flowered parent must have included 50 percent pink flowered plants.

B

Humans have a diploid number (2n) of 46. Which of the following statements best predicts the consequence if meiosis did not occur during gametogenesis?* A.The gametes would get larger from one generation to the next. B.The chromosome number would double with each generation. C.The chromosome number would be halved with each generation. D. The chromosome number would triple with each generation.

B

In pea plants, flower color and the length of the flower's pollen grains are genetically determined. Researchers studying pea plants crossed homozygous dominant pea plants with homozygous recessive pea plants. The plants were then crossed, and the number of offspring with each phenotype was recorded. The researchers' observed data, however, differed from the expected data. The researchers did a chi-square analysis and calculated the chi-square value to be 5.5. Based on their calculation, the researchers would most likely conclude which of the following?* A.The genes that determine these two traits are likely on the same chromosome. B.The differences between observed data and expected data are due to chance. C.The genes mutated since the researchers began the experiment and now have a different inheritance pattern. D. The allele frequencies of the offspring have changed, suggesting the population is evolving.

B

Both mitosis and meiosis begin with a parent cell that is diploid. Which of the following best describes how mitosis and meiosis result in daughter cells with different numbers of chromosomes?* A.In mitosis, the chromosomes consist of a single chromatid, which is passed to two haploid daughter cells. In meiosis, the chromosomes consist of two chromatids during the first round of division and one chromatid during the second round of division, resulting in two haploid daughter cells. B.Mitosis produces one identical daughter cell after one round of division. Meiosis has two rounds of division and doubles the number of chromosomes in the second round of division, producing four diploid cells. C.Mitosis produces two identical diploid daughter cells after one round of division. Meiosis produces four haploid daughter cells after two rounds of division.

C

If 2n = 48 for a particular cell, then the chromosome number in each cell after meiosis would be:* A.96 B.48 C.24 D.12 E.6

C

In a certain type of chicken, the allele for gray feathers is recessive to the allele for black feathers, and the allele for a spotted pattern is recessive to the allele for a solid pattern. Chickens that are heterozygous for both traits were crossed and the phenotypes for the offspring were recorded (Table 1). To determine whether the data are consistent with the expectations for independent assortment, students performed a chi-square analysis.Which of the following is the closest to the calculated chi-square value for the experiment?* A.-0.26 B.0.20 C.0.95 D. 1.25

C

Table I shows the results of breeding experiments to examine the inheritance of flower color (purple versus white) and pod shape (inflated versus constricted). For the crosses recorded in Table I, true-breeding parents were crossed to produce F1offspring, which were then test crossed to homozygous recessive individuals. Table II shows the results of computer simulated crosses to model the inheritance of leaf shape (broad versus narrow) and flower color (purple versus white). A.close together on the same autosome B.on the X chromosome C.on different chromosomes D. on a mitochondrial chromosome

C

Which of the following best describes the cellular process illustrated in Figure 1 ? A.Sister chromatids separating during anaphase of mitosis B. Chromosomes lining up along the midline of the cell during mitosis C.Reducing the chromosome number during anaphase of meiosis D. Chromatids failing to separate during meiosis

C

The process depicted in the image below is best summarized by which of the following descriptions?* A.During the synthesis phase of the cell cycle, DNA molecules replicate to generate identical daughter cells. B.Centromeres align specific gene sequences of homologous chromosomes during mitotic divisions. C.The spindle apparatus attaches at chiasma during metaphase of mitosis. D.During meiosis, crossing over leads to recombination of alleles between homologous chromosomes.

D

Describe the sequence of events that make up the alternation of generations in plants. Include an explanation of where mitosis and meiosis occur in the sequence. You may use a labeled diagram as part of your answer.

Plants will go through a phase in their lives called gametophyte, in which they are made of haploid cells and create gametes to release. These gametes will fertilize and create a sporophyte plant as offspring. Mitosis occurs when the plant becomes a gametophyte, and meiosis occurs in order for the plants to create gametes.

...What is it about HeLa cells that make them immortal?

The enzyme telomerase copies over and over again which prevents cell death and aging. Telomeres are supposed to shorten which lessens the amount of times they can divide however, Hela cells continuously grow

Discuss TWO differences between gametogenesis in male humans and gametogenesis in female humans.

Woman gametogenesis occurs in the ovaries while it occurs in the testes for males. The process for females is called oogenesis and produces eggs and the process for males is called spermatogenesis and produces sperm.

The events listed below generally take place during meiosis. I. Synapsis occurs. II. Crossing-over is completed. III. Condensation of chromosomes begins. IV. Separation of homologous chromosomes begins. Which of the following is the correct sequence of these events?* 0/1 A. I, II, III, IV B. II, I, III, IV C. III, I, II, IV D.III, IV, II, I E. IV, II, III, I

c