FACULTY OF PURE AND APPLIED SCIENCE
FALL TERM EXAMINATION

NATS 1660: The Biology of Sex

2002/2003 FALL TERM

2 hrs

No permitted aids

1. A population would be considered to be evolving if:

(a) the population was reduced to a very small number of individuals.

(b) the population came to include more individuals with advantageous characteristics

(c) the population moved to another location where it would survive more easily

(d) the population had more offspring

(e) the population learned to survive in different conditions

2. The inheritance of acquired characteristics, proposed by Jean-Baptiste Lamarcke, states that:

(a) individuals pass on characteristics that they acquire during their lifetime to their offspring

(b) random chance determines survival of the offspring

(c) some individuals have learned how to survive from their parents

(d) better adapted populations have more characteristics

(e) variation in traits is important

3. A polymorphic locus describes:

(a) an insect with multiple traits

(b) a position on the DNA with only one allele

(c) a position on the DNA with multiple alleles

(d) the position of the DNA in the nucleus

(e) multiple types of DNA and RNA

4. Hardy and Weinberg are famous for:

(a) solving the puzzle of why genetic variation persists

(b) showing original proportions of genotypes can remain constant from generation to generation

(c) inventing microevolution

(d) none of the above

(e) a and b

5. Gene flow describes a situation where:

(a) genotypes disappear from the population

(b) phenotypes overtake genotypes

(c) differences in populations are further supported

(d) alleles move from one population to another

(e) populations diverge genetically

6. Genetic drift can be described as:

(a) bad luck

(b) change by chance alone

(c) natural selection at work

(d) directed selection

(e) occuring in large populations

7. In order for selection to occur:

(a) variation must exist among individuals

(b) variation must result in difference in numbers of viable offspring

(c) variation must be genetically inherited

(d) a and c

(e) all of the above

8. Disruptive selection:

(a) is caused by artificial means

(b) eliminates intermediate types

(c) eliminates one extreme

(d) eliminates both extremes

(e) quantifies reproductive success

9. Species concepts must account for

(a) the distinctiveness of species occurring together in a single locality

(b) connections among populations of the same species that are geographically separated.

(c) how directional selection occurs

(d) why sibling species occur

(e) a and b

10. The biological species concept:

(a) states that species are reproductively isolated from each other

(b) explains successful multi-generational hybridization

(c) supports differences in asexual species

(d) is not used in current times

(e) is accepted by all current scientists

11. Species that do not occur together in nature are usually termed:

(a) allopatric species

(b) sympatric species

(c) sister species

(d) interbreeding species

(e) phylopatric species

12. Hybrid breakdown refers to:

(a) a type of pre-zygotic isolating mechanism

(b) a type of post-zygotic isolating mechanism

(c) when a hybrid shows abnormal sex organ development

(d) a type of temporal isolation

(e) a type of artificially induced mutation

13. Speciation is often described as a two-part process. These two parts are:

(a) two population must connect; reproductive isolation must evolve

(b) two populations must diverge; reproductive isolation must stop

(c) two population must diverge; reproductive isolation must evolve

(d) two populations must connect; reproductive isolation must stop

(e) two populations must diverge; reproductive isolation is not important

14. Island biogeography is closely connected to:

(a) Darwin’s finches

(b) the principles of adaptive radiation

(c) the principles of zygotic isolating mechanisms

(d) all of the above

(e) a and b

15. Reproductive strategies involve:

(a) maximizing reproductive success

(b) deciding on the choice of a mate

(c) the type of parental care shown

(d) all of the above

(e) none of the above

16. Parental investment refers to:

(a) an estimate of the energy spent by males and females in offspring care

(b) mate choice by males

(c) the energetic equations used to determine who will provide the most care

(d) the energy used to physically produce the offspring

(e) the energy used to raise the offspring

17. Sexual selection can be described as:

(a) distinct from natural selection

(b) two separate types of selection

(c) competition for mating opportunities

(d) none of the above

(e) all of the above

18. When individuals of one sex compete, this is an example of:

(a) intersexual selection

(b) intrasexual selection

(c) mate choice

(d) extrasexual selection

(e) none of the above

19. Sexual dimorphism may be a result of:

(a) mate choice

(b) healthy males succeeding more

(c) developing structures to fight with

(d) all of the above

(e) none of the above

20. Polygyny is best described as:

(a) one male to one female

(b) one male to multiple females

(c) one female to multiple males

(d) multiple females and multiple males

(e) a type of polyandry

21. The evolution of sex is a puzzle because:

(a) the advantage is for the population, not the individual

(b) nobody knows when it started

(c) asexual reproduction is clearly a disadvantage

(d) genetic recombination doesn’t make any difference

(e) budding is a common strategy

22. Theories on the origin of sex include:

(a) the RNA repair hypothesis

(b) Muller’s ratchet

(c) the “if it feels good, do it” theory

(d) the random fertilization theory

(e) the standardized mutation hypothesis

23. If the Red Queen Hypothesis holds, then you would expect to see

(a) snails on a treadmill

(b) parasites destroying the host population

(c) oscillations between host and parasite genotypes

(d) hosts evolving complete protection from the parasites

(e) parasites switching hosts regularly

24. The SRY region on a chromosome will

(a) cause female human genitals to form

(b) can act at any time during development

(c) cause male human genitals to form

(d) be a lethal mutation

(e) determine whether the Red Queen hypothesis will occur

25. Oviparity is a strategy of

(a) internal fertilization

(b) all birds

(c) all reptiles

(d) all of the above

(e) a and b

26. The cloaca describes a structure that:

(a) is found in mammals

(b) combines the exit of several organ systems

(c) is responsible for internal fertilization

(d) is part of the penis

(e) is used during mate choice

27. If fertilization is external, the eggs develop in water, and there are distinct developmental stages, the organism is a(n):

(a) bird

(b) bony fish

(c) cartilagenous fish

(d) reptile

(e) amphibian

28. Parthogenesis is:

(a) a type of hermaphroditism

(b) common in many species

(c) the production of offspring from unfertilized eggs

(d) all of the above

(e) b and c

29. The difference between protogyny and protoandry is:

(a) whether there is dual fertilization

(b) whether the fertilization is internal or external

(c) whether the original sex survives

(d) the original sex before the change

(e) whether there is parthogenesis involved

30. Vulva refers to:

(a) the area covering the pubic bone

(b) the female external genital structures

(c) the vagina

(d) the large outer lips

31. Which of the following statements regarding the clitoris is false?

(a) it has approximately the same number of nerve endings as the head of the penis

(b) the only purpose of the clitoris is sexual arousal

(c) clitoral stimulation is the most common way women produce arousal and orgasm during self-stimulation

(d) it is located within the introitus

32. The labia majora encloses all of the following except:

(a) clitoris

(b) mons veneris

(c) introitus

(d) urethral opening

33. The vestibule:

(a) contains the clitoris and the prepuce

(b) refers to the clitoral shaft that houses the cavernous bodies

(c) is where the urinary and vaginal openings are located

(d) is the area between the introitus and the anus

34. The vestibular bulbs:

(a) produce a drop or two of fluid just prior to orgasm

(b) engorge with blood during sexual arousal, causing the vagina to increase in length

(c) are located in the shaft of the clitoris

(d) contain the spongy structures called the cavernous bodies

35. Which of the following statements regarding vaginal lubrication is false?

(a) it is the first physiological sigh of sexual arousal in women

(b) it seeps through the vaginal walls as vasocongestion occurs

(c) it occurs within 10 to 30 seconds after effective psychological or physical stimulation begins

(d) the primary source of the fluid is the vestibular bulbs

36. The tissue that lines the uterus is the

(a) the perimetrium

(b) the myometrium

(c) the endometrium

(d) the hymen

37. Which of the following statements regarding sperm production is false?

(a) it takes place within the seminiferous tubules

(b) it usually begins after the onset of puberty

(c) it constitutes up to 70 % of the seminal fluid

(d) it usually continues until death

38. Which of the following courses does a sperm cell follow on its way to the exterior body of the male?

(a) testes, epididymis, vas deferens, urethra

(b) epididymis, testes, urethra, vas deferens

(c) epididymis, vas deferens, testes, urethra

(d) testes, vas deferens, epididymis, urethra

39. The Cowper’s glands secrete a fluid when a man becomes sexually aroused

(a) that is acidic in nature

(b) that may contain active sperm

(c) that functions as a vaginal lubricant during intercourse

(d) that is released during the emission phase of ejaculation

40. Which of the following statements regarding the male ejaculate is true?

(a) the fluid is highly alkaline in nature

(b) the major portion of the fluid is derived from the prostate gland

(c) the amount of fluid a man ejaculates is approximately three tablespoons

(d) it consists of fluid that come from the seminal vesicles, prostate and Bartholin’s glands

41. All of the following are factors in the amount of seminal fluid a man ejaculates except

(a) the length of time since last orgasm

(b) the duration of arousal time prior to ejaculation

(c) a man’s age

(d) how physically fit a man is

42. Sperm production in the male requires a temperature that

(a) is higher that body temperature

(b) is lower than body temperature

(c) is the same as body temperature

(d) varies from high to low temperatures from day to day

43. Which of the following statements regarding testosterone is false?

(a) erectile difficulties may sometimes be associated with testosterone deficiency

(b) testosterone deficiency may result in decreased genital sexual pleasure for men

(c) testosterone is produce by both ovaries and the adrenals in women

(d) testosterone plays a role in female sexuality but it is secondary to the influence of estrogen

44. Which of the following is most influential in sexual motivation in both men and women?

(a) bound (attached) testosterone

(b) unbound (free) testosterone

(c) total testosterone

(d) estrogen

45. One of the significant features of Kaplan’s model is that it includes _______ as a distinct phase of the sexual response cycle.

(a) desire

(b) excitement

(c) plateau

(d) refractory

46. ___________ is the engorgement with blood of body tissues that respond to sexual excitation.

(a) labioscrotal swelling

(b) mytonia

(c) tumescence

(d) vasocongestion

47. Which of the following statements concerning the Grafenberg (G) spot is true?

(a) when this area is stimulated, some women ejaculate a fluid that is chemically similar to male prostate secretions.

(b) the erotic significance of the area was first discussed in the medical literature at the end of the 19^th century

(c) it is an area approximately the size of a dime, located on the cervix

(d) very gentle stimulation of the area should be used in order for a woman to respond.

48. The spermatozoa

(a) is a complex cell

(b) has a head capped by an acrosome

(c) has a head containing mitochondria

(d) has a tail containing the DNA

49. FSH (follicle stimulating hormone) and LH (lutinizing hormone)

(a) regulate reproductive function in males

(b) stimulate Sertoli cells to secrete testosterone

(c) trigger menarche and the formation of secondary sex characteristics

(d) control the completion of meiosis in eggs

50. Menstruation

(a) occurs when the ovum is fertilized

(b) is present in mammals with an estrous cycle

(c) is absent in mammals with an estrous cycle

(d) occurs when the perineum is sloughed off

51. List the 5 assumptions for the Hardy-Weinberg Principle to hold. (5 marks)

a. _____________________________________________________________________

_______________________________________________________________________

b.____________________________________________________________________________________________________________________________________________

c.______________________________________________________________________

_______________________________________________________________________

d. _____________________________________________________________________

_______________________________________________________________________

e.____________________________________________________________________________________________________________________________________________

population is large

random mating

no mutation

no gene input from external sources (no gene flow)

no natural selection

52. What is occuring if a population in not in Hardy-Weinberg equilibrium? (1 mark)

______________________________________________________________________

it is evolving

53. The founder effect and the bottleneck effect are both examples of _____________________________? (1 mark)

genetic drift

54. Evolution is an outcome of which process? (1 mark)

natural selection

55. Name two (2) of the four (4) key classification characteristics of bacterial diversity. (2 marks)

a.______________________________________________________________________

b.______________________________________________________________________

Photosynthetic or Nonphotosynthetic; Motile or Nonmotile; Unicellular or Multicellular; Spore Formation or Division by Transverse Binary Fission

56. A B C

Name and describe what is happening in:

A: _____________________________________________________________________

_______________________________________________________________________

B:______________________________________________________________________________________________________________________________________________

C: ______________________________________________________________________

(6 marks)

A: disruptive, selection against the mean

B: directional, selection against one extreme

C: stabilizing, selection against both extremes

57.

(a) What is the full name of the process shown above? (1 mark)

_______________________________ Cell cycle

(b) What type of cell would this occur in? (1 mark)

___________________________________ body or somatic cell

58. List the three strategies of internal fertilization and briefly describe what makes them different from each other (6 marks)

a. _____________________________________________________________________

_______________________________________________________________________

b.____________________________________________________________________________________________________________________________________________

c.______________________________________________________________________

_______________________________________________________________________

(oviparity: egg fertilized internally, deposited outside mother’s body to complete development

ovoviparity: fertilized eggs retained inside mother’s body, all nourishment gained from yolk sac

viviparity: young develop within mother and obtain nourishment directly from mother’s blood.)

59.

(a) What is this image describing? (1 mark)

__________________________________________ The sexual response cycle

(b) Does this represent a male or a female? (1 mark)

__________________________________________ A male

(c) Name the first three stages not labelled on this diagram (3 marks)

________________________________________

________________________________________

________________________________________

(excitement, plateau, orgasm)

60. Virgin birth is also known as _____________________________ (1 mark) parthogenesis

61. In order, list the 5 components of the central dogma (5 marks)

a. __________________________________

b. __________________________________

c. __________________________________

d. __________________________________

e. __________________________________

DNA; transcription; mRNA; translation; protein

62. Name two methods of birth control. Describe one positive and one negative feature of each method. (6 marks)

a. ______________________________________________________________________

_______________________________________________________________________

________________________________________________________________________

b. ______________________________________________________________________

________________________________________________________________________

________________________________________________________________________

63. What are the four (4) types of macromolecules? (4 marks)

a. ______________________________________________________________________

b. ______________________________________________________________________

c. ______________________________________________________________________

d. ______________________________________________________________________

(proteins, lipids, nucleic acids, carbohydrates)

64. Name two features of a cell and describe their functions. (4 marks)

a. ______________________________________________________________________

______________________________________________________________________

b. ______________________________________________________________________

______________________________________________________________________

nucleus: information centre

golgi apparatus: collects, packages, distributes molecules around the cell

mitochondria: cell’s energy source

chloroplasts: where photosynthesis takes place in plants

vacuoles: storage centre for cell

65. Sex-linked traits are usually carried on the _________chromosome. (1 mark)

Y chromosome