Biology 8.11-8.23

Two chromosomes in a nucleus that carry loci for the same traits in the same positions on the chromosome but specify different versions of some traits constitute a pair of A) homologous chromosomes. B) heterologous chromosomes. C) complementary chromosomes. D) polyploid chromosomes. E) parallel chromosomes.

A pair of male human sex chromosomes is most like A) a pair of blue jeans. B) a bride and groom. C) a knife, fork, and spoon. D) identical twins. E) the letters of the alphabet.

Which of the following statements regarding mitosis and meiosis is false? A) Meiosis only occurs in the ovaries and testes. B) All sexual life cycles involve an alternation of diploid and haploid stages. C) Mitosis produces daughter cells with half the number of chromosomes as the parent cell. D) A normal human zygote has 46 chromosomes. E) A haploid cell has half the chromosomes of a diploid cell.

Which of the following statements is false? A) A typical body cell is called a somatic cell. B) Gametes are haploid cells. C) Somatic cells are diploid. D) Gametes are made by mitosis. E) A zygote is a fertilized egg.

During which stage of meiosis does synapsis and the formation of tetrads occur? A) interphase I B) prophase I C) interphase II D) prophase II E) metaphase I

Which of the following options correctly describes the behavior of a tetrad during anaphase I of meiosis? A) It goes intact to one pole of the dividing cell. B) It splits into two pairs of sister chromatids, and one pair goes to each pole of the dividing cell. C) It splits into two pairs of homologous, nonsister chromatids, and one pair goes to each pole of the dividing cell. D) It splits into four chromosomes, which distribute in random pairs to the two poles of the dividing cell. E) It splits into four chromosomes, which distribute in sister-chromosome pairs to the two poles of the dividing cell.

Which of the following statements regarding the differences between mitosis and meiosis is false? A) In meiosis four daughter cells are produced, whereas in mitosis two daughter cells are produced. B) Cells produced by mitosis are diploid, whereas cells produced by meiosis are haploid. C) In mitosis cytokinesis occurs once, whereas in meiosis cytokinesis occurs twice. D) Crossing over is a phenomenon that creates genetic diversity during mitosis. E) Mitosis, but not meiosis, occurs in somatic cells.

Which of the following statements regarding mitosis and meiosis is false? A) Mitosis provides for growth and tissue repair. B) Meiosis provides for asexual reproduction. C) In mitosis, the chromosomes replicate only once in the preceding interphase. D) In meiosis, the chromosomes replicate only once in the preceding interphase. E) All the events unique to meiosis occur during meiosis I.

Both mitosis and meiosis are preceded by A) prometaphase. B) interphase. C) prophase. D) telophase. E) anaphase.

Independent orientation of chromosomes at metaphase I and random fertilization are most like A) shuffling cards and dealing out hands of poker. B) cutting up a pie into eight even-sized slices. C) alphabetizing files in a filing cabinet. D) pairing up similar socks after washing your clothes. E) stringing beads onto a string to make a necklace.

Independent orientation of chromosomes at metaphase I results in an increase in the number of A) gametes. B) homologous chromosomes. C) possible combinations of characteristics. D) sex chromosomes. E) points of crossing over.

Which of the following statements regarding genetic diversity is false? A) Genetic diversity is enhanced by random fertilization. B) Genetic diversity is enhanced by independent orientation of chromosomes at metaphase I. C) Genetic diversity is enhanced by mitosis of somatic cells. D) Genetic diversity is enhanced by crossing over during prophase I of meiosis. E) Genetic diversity is enhanced by random mutations of the DNA.

Karyotyping A) shows chromosomes as they appear in metaphase of meiosis II. B) can reveal alterations in chromosome number. C) examines points of crossing over. D) reveals the results of independent orientation of chromosomes during meiosis I. E) reveals the presence of cancerous genes.

A karyotype is most like A) a map showing the hidden location of buried treasure. B) a movie showing the stages of the reproductive cycle of a beetle. C) a necklace formed by stringing beads onto a string. D) photographs of every couple at a high school prom. E) the answer key to a multiple-choice exam.

Which of the following statements regarding Down syndrome is false? A) Trisomy 21 usually leads to Down syndrome. B) A human embryo with an abnormal number of chromosomes is usually spontaneously aborted. C) Down syndrome is the most common serious birth defect in the United States. D) People with Down syndrome usually have a life span much shorter than normal. E) Women with Down syndrome cannot reproduce.

Nondisjunction occurs when A) a portion of a chromosome breaks off and is lost. B) chromosomes replicate too many times. C) two chromosomes fuse into one. D) members of a chromosome pair fail to separate. E) an entire pair of chromosomes is lost during meiosis I.

Which of the following statements about nondisjunction is false? A) Nondisjunction in meiosis can affect autosomes and sex chromosomes. B) In mammals, extra copies of the Y chromosome are typically inactivated. C) The absence of a Y chromosome results in "femaleness." D) In general, a single Y chromosome is enough to produce "maleness." E) Women with a single X chromosome have Turner syndrome and are sterile.

Which of the following types of organisms commonly demonstrates polyploidy? A) mammals B) reptiles C) flowering plants D) amphibians E) fish

How many generations does it take to develop a new plant species by nondisjunction? A) one B) two C) ten D) twenty E) fifty

Which of the following variations of the sentence "Where is the cat" is most like a chromosomal deletion? A) Where is cat? B) Where is the the cat? C) Where the is cat? D) Where is cat the the cat? E) Where is is is is the cat?

If a chromosome fragment breaks off and then reattaches to the original chromosome, but in the reverse direction, the resulting chromosomal abnormality is called a(n) A) deletion. B) inversion. C) translocation. D) nondisjunction. E) reciprocal translocation.

Cancer is not usually inherited because A) the chromosomal changes in cancer are usually confined to somatic cells. B) people with cancer usually die before reproducing. C) cancer typically causes disruptions of meiosis. D) the causes of cancer are not usually genetic. E) the cancerous cells usually interfere with the ability to produce gametes.

Mr. and Mrs. Smith have three sons in elementary school. Two of their children are progressing normally, but their last son, Charles, has been much slower than his siblings at developing speech and language skills. His parents are concerned that he has a learning disability and decide to investigate further. Since some learning disabilities can be genetically based, their pediatrician recommends a chromosomal analysis. The results show that Charles has a trisomy of the sex chromosomes, diagnosed as XYY, which is caused by nondisjunction in the formation of the father's sperm. The nondisjunction resulted in an extra copy of the Y chromosome. The extra copy was passed on to Charles during fertilization. Most often, this chromosomal change causes no unusual physical features or medical problems, but those with trisomy of the sex chromosomes do have a higher than normal risk of delays in learning development. 1) During which stage of meiosis must this nondisjunction have occurred? A) anaphase I B) metaphase I C) metaphase II D) anaphase II E) prophase II

If Charles gets married and starts a family, which of the following chromosomal abnormalities might be found in his children? A) XY B) XX C) XYY D) XO E) XXY