Biology Chapter Three Study Guide

24. Which of the following occurs in meiosis but not in mitosis? A) Homologous chromosomes of a pair are separated from each other. B) The chromosome number per cell remains the same. C) Sister chromatids are separated. D) Four daughter cells are formed.

ANSWER: A) Homologous chromosomes of a pair are separated from each other REMEMBER: meiosis but not mitosis is homologous

23. What is the normal complement of sex chromosomes in a human male? A) one X chromosome and one Y chromosome B) two X chromosomes C) two Y chromosomes D) two X chromosomes and one Y chromosome E) one Y chromosome

ANSWER: A) one X chromosomes and one Y chromosome REMEMBER: 1 x and 1 y

36. Mendel conducted his most memorable experiments on A) peas. B) roses. C) guinea pigs. D) fruit flies. E) clones.

ANSWER: A) peas

14. 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

ANSWER: A) the chromosomal changes in cancer are usually confined to somatic cells REMEMBER: cancer is not inherited because of chromosomal changes

7. Looking into your microscope, you spot an unusual cell. Instead of the typical rounded cell shape, the cell has a very narrow middle separating two bulging ends. It sort of looks like the number 8! Then you realize that this cell is A) undergoing cytokinesis B) in the S phase of interphase C) in the G1 phase of interphase D) in the G2 phase of interphase E) about to undergo mitosis

ANSWER: A) undergoing cytokinesis REMEMBER: rounded cell shape = undergoing cytokinesis

3. Asexual reproduction requires _____ individual(s). A) 0 B) 1 C) 2 D) 3 E) 4

ANSWER: B) 1 REMEMBER: Asexual only requires one partner

42. Assuming that the probability of having a female child is 50% and the probability of having a male child is also 50%, what is the probability that a couple's first-born child will be female and that their second-born child will be male? A) 20% B) 25% C) 50% D) 75% E) 100%

ANSWER: B) 25%

35. Which of the following statements best represents the theory of pangenesis developed by Hippocrates? A) Pregnancy is a spontaneous event, and the characteristics of the offspring are determined by the gods. B) Particles called pangenes, which originate in each part of an organism's body, collect in the sperm or eggs and are passed on to the next generation. C) Offspring inherit the traits of either the mother or the father, but not both. D) Fertilization of plants is dependent on an animal. E) Heritable traits are influenced by the environment and the behaviors of the parents.

ANSWER: B) Particles called pangenes, which originate in each part of an organism's body, collect in the sperm or eggs and are passed on to the next generation.

38. Research since Mendel's time has established that the law of the segregation of genes during gamete formation A) applies to all forms of life. B) applies to all sexually reproducing organisms. C) applies to all asexually reproducing organisms. D) applies only to unicellular organisms. E) is invalid.

ANSWER: B) applies to all sexually reproducing organisms.

28. 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.

ANSWER: B) can reveal alterations in chromosome number.

20. The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called A) mitosis B) cytokinesis C) binary fission D) telophase E) spindle formation

ANSWER: B) cytokinesis REMEMBER: cytoplasm of a eukaryotic cell divides into two through cytokinesis

49. Linked genes generally A) follow the laws of independent assortment. B) do not follow the laws of independent assortment. C) show incomplete dominance. D) reflect a pattern of codominance. E) show pleiotropy

ANSWER: B) do not follow the laws of independent assortment.

26. Crossing over normally takes place during which of the following processes? A) meiosis II B) meiosis I C) mitosis D) mitosis and meiosis II

ANSWER: B) meiosis I

27. Homologous pairs of chromosomes align opposite of each other at the equator of a cell during _____. A) mitosis metaphase B) meiosis metaphase I C) meiosis telophase II D) meiosis metaphase II

ANSWER: B) meiosis metaphase I

44. The vast majority of people afflicted with recessive disorders are born to parents who were A) both affected by the disease. B) not affected at all by the disease. C) slightly affected by the disease, showing some but not all of the symptoms. D) subjected to some environmental toxin that caused the disease in their children. E) affected by the disease but had subclinical symptoms.

ANSWER: B) not affected at all by the disease.

16. The phase of mitosis during which the nuclear envelope fragments and the nucleoli disappear is called A) interphase B) prophase C) metaphase D) anaphase E) telophase

ANSWER: B) prophase REMEMBER: nuclear envelope fragments and nucleoli disappear = prophase

19. During which stage of meiosis does synapsis and the formation of tetrads occur? A) interphase 1 B) prophase 1 C) interphase 2 D) prophase 2 E) metaphase 1

ANSWER: B) prophase 1 REMEMBER: the formation of tetrads occur during prophase 1

43. Most genetic disorders of humans are caused by A) multiple alleles. B) recessive alleles. C) drinking during pregnancy. D) a mutation that occurs in the egg, sperm, or zygote. E) dominant alleles.

ANSWER: B) recessive alleles

50. Crossing over ________ genes into assortments of ________ not found in the parents. A) recombines unlinked . . . genes B) recombines linked . . . alleles C) combines unlinked . . . alleles D) combines linked . . . genes E) recombines unlinked . . . chromosomes

ANSWER: B) recombines linked . . . alleles

25. Which of the following occurs in meiosis but not in mitosis? A) chromosome replication B) synapsis of chromosomes C) alignment of chromosomes at the equator D) condensation of chromosomes

ANSWER: B) synapsis of chromosomes

48. The chromosome theory of inheritance states that A) chromosomes that exhibit mutations are the source of genetic variation. B) the behavior of chromosomes during meiosis and fertilization accounts for patterns of inheritance. C) the behavior of chromosomes during mitosis accounts for inheritance patterns. D) humans have 46 chromosomes. E) the inheritance pattern of humans is predetermined from chromosomes.

ANSWER: B) the behavior of chromosomes during meiosis and fertilization accounts for patterns of inheritance.

29. When homologous chromosomes cross over, what occurs? A) Two chromatids get tangled, resulting in one re-sequencing its DNA. B) Two sister chromatids exchange identical pieces of DNA. C) Corresponding segments of non-sister chromatids are exchanged. D) Maternal alleles are "corrected" to be like paternal alleles and vice versa.

ANSWER: C) Corresponding segments of non-sister chromatids are exchanged.

13. What process occurs when cancer cells detach from tumors and spread to other pats of the body A) Angiogenesis B) Carcinogenesis C) Metastasis D) Mutagenesis

ANSWER: C) Metastasis REMEMBER: when cancer cells detach it's called Metastasis

2. Asexual reproduction occurs during____. A) chromosome exchange between organisms of different species B) meiosis C) mitosis D) fertilization

ANSWER: C) Mitosis REMEMBER: Asexual reproduction = Mitosis

9. The genetic material is duplicated during A) the mitotic phase B) G1 C) S phase D) G2 E) mitosis

ANSWER: C) S phase REMEMBER: genetic material is duplicated during the S phase

46. Which of the following statements regarding sickle-cell disease is false? A) Sickle-cell disease is common in tropical Africa. B) Persons who are heterozygous for sickle-cell disease are also resistant to malaria. C) Sickle-cell disease causes white blood cells to be sickle-shaped. D) All of the symptoms of sickle-cell disease result from the actions of just one allele. E) About one in ten African-Americans is a carrier of sickle-cell disease.

ANSWER: C) Sickle-cell disease causes white blood cells to be sickle-shaped.

37. A monohybrid cross is A) the second generation of a self-fertilized plant. B) a breeding experiment in which the parental varieties have only one trait in common. C) a breeding experiment in which the parental varieties differ in only one character. D) a triploid plant that results from breeding two very different plants. E) a breeding experiment in which the parental varieties have only one prominent trait.

ANSWER: C) a breeding experiment in which the parental varieties differ in only one character.

15. A benign tumor differs from a malignant rumor in that a benign tumor A) is cancerous B) spreads from the original site C) does not metastasize D) never causes health problems E) can only arise in the brain, whereas a malignant tumor can arise anywhere in the body

ANSWER: C) does not metastasize REMEMBER: a benign tumor does not metastasize

22. The human X and Y chromosomes ____. A) are both present in every somatic cell of males and females B) are the same size and have the same number of genes C) include genes that determine an individual's sex D) are called autosomes

ANSWER: C) include genes that determine an individual's sex REMEMBER: X and Y chromosomes include genes that determine and individuals sex

17. During which phase of mitosis do the chromosomes line up on a plane equidistant from the two spindle poles? A) interphase B) prophase C) metaphase D) anaphase E) telophase

ANSWER: C) metaphase REMEMBER: mitosis lines up during metaphase

12. What means the term Apoptosis? A) Angiogenesis B) Carcinogenesis C) Cell differentiation D) Programmed Cell death E) Natural Cell Killer

ANSWER: D) Programmed Cell death REMEMBER: Apoptosis = Programmed Cell death

1. Which of the following defines a genome? A) the complete set of an organism's polypeptides B) the complete set of a species' polypeptides C) a karyotype D) the complete set of an organism's DNA

ANSWER: D) The complete set of an organism's DNA REMEMBER: Genome = set of DNA

10. Which of the following occurs during the interphase? A) a reduction in the size of the nuclear membrane B) duplication of the chromosomes C) cytokinesis D) cell growth and duplication of the chromosomes E) separation of newly formed DNA to opposite ends of the cell

ANSWER: D) cell growth and duplication of the chromosomes REMEMBER: cell growth duplication occurs during duplication

39. All the offspring of a cross between a black-eyed mendelien and an orange-eyed mendelien have black eyes. This means that the allele for black eyes is ________ the allele for orange eyes. A) codominant to B) recessive to C) more aggressive than D) dominant to E) better than

ANSWER: D) dominant to

41. Mendel's law of independent assortment states that A) chromosomes sort independently of each other during mitosis and meiosis. B) genes sort independently of each other in animals but not in plants. C) independent sorting of genes produces polyploid plants under some circumstances. D) each pair of alleles segregates independently of the other pairs of alleles during gamete formation. E) genes are sorted concurrently during gamete formation.

ANSWER: D) each pair of alleles segregates independently of the other pairs of alleles during gamete formation.

21. If meiosis produces haploid cells, how is the diploid number restored for those organisms that spend most of their life cycle in the diploid state? A) DNA replication B) reverse transcription C) synapsis D) fertilization

ANSWER: D) fertilization REMEMBER: if meiosis produces haploid cells its fertilization

45. All the offspring of a cross between a red-flowered plant and a white-flowered plant have pink flowers. This means that the allele for red flowers is ________ to the allele for white flowers. A) dominant B) codominant C) pleiotropic D) incompletely dominant recessive

ANSWER: D) incompletely dominant recessive

40. The phenotypic ratio resulting from a dihybrid cross showing independent assortment is expected to be A) 1:2:1. B) 3:1. C) 9:1:1:3. D) 3:9:9:1. E) 9:3:3:1.

ANSWER: E) 9:3:3:1.

11. The out of control of any cell during cell division result in a process known as A) Metastasis B) Apoptosis C) Cell differentiation D) Dysplasia E) Cancer

ANSWER: E) Cancer REMEMBER: out of control cell division = cancer

8. Which of the following statements regarding the cell-cycle control system is false? A) The cell-cycle control system receives messages from outside the cell that influence cell division B) The cell-cycle control system triggers and controls major events in the cell cycle C) The cell-cycle control system is influenced by growth factors that bind to cell receptors D) The cell-cycle control system includes three key checkpoints to complete a cell cycle E) The cell-cycle control system operates independently of growth factors

ANSWER: E) The cell-cycle control system operates independently of the growth factors REMEMBER: the cell-cycle control system is an individual system

4. Eukaryotic chromosomes differ from prokaryotic chromosomes in that they A) are simpler B) are circular in structure C) include fewer proteins D) are copied immediately after cell division E) are housed in a membrane-enclosed nucleus

ANSWER: E) are housed in a membrane-enclosed nucleus REMEMBER: Eukaryotic is different from prokaryotic due to the membrane-enclosed nucleus

51. The mechanism that "breaks" the linkage between linked genes is A) incomplete dominance. B) pleiotropy. C) codominance. D) independent assortment. E) crossing over.

ANSWER: E) crossing over

47. The individual features of all organisms are the result of A) genetics. B) the environment. C) genetics and cytoplasmic determinants. D) the environment and individual needs. E) genetics and the environment.

ANSWER: E) genetics and the environment

5. Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called A) chromatin B) sister chromosomes C) DNA transcripts D) nucleoli E) sister chromatids

ANSWER: E) sister chromatids REMEMBER: Each chromosome of a eukaryotic cell is a sister chromatid not a sister chromosome

18. During which phase of mitosis does the nuclear envelope re-from and the nucleoli reappear? A) anaphase B) metaphase C) prophase D) interphase E) telophase

ANSWER: E) telophase REMEMBER: reappear = telophase

6. 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

ANSWER: Gametes are made by mitosis REMEMBER: Gametes are NOT made by mitosis