Quiz 12 KEY (9 Points). Reading: Wedekind (1995) & Dr. Tatiana, Pgs 187-211

Quiz 12 KEY (9 points). Reading: Wedekind (1995) & Dr. Tatiana, pgs 187-211.

NATS 104, April 17, 2003

Questions 1 and 2 are from Dr. Tatiana, the rest are from the article on mate choice by Wedekind.

1) What is unusual about the way that spotted hyenas give birth? (1 pt)

They give birth through their clitoris rather than vaginally.

2) What is unusual about the number of sexes in slime molds? (1 pt)

There are many different sexes (hundreds) rather than just two.

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3) What were the male participants in the mate choice study asked to do? (1 pt)

They were asked to wear T shirts (organic, cotton) for a few days. (full credit)

Additional information: Tee shirts were meant to pick up the men’s natural odor.They also asked to avoid activity that would cause strong smells that might interfere with their own smells, such as no sex, spicy foods, deodorant, perfume or perfumed soap, and to sleep alone for three days)

Researchers took blood from males and female participants to determine their MHC

4) What were the female participants in the mate choice study asked to do? (1 pt)

to smell the tee shirts and tell the researchers if the odor was pleasant/reminded them of boyfriend (full credit)

Additional information: They also were asked if the odor was strong, and if it reminded them of a past boyfriend or of a relative. Beforehand they were asked to use a nasal spray for a few weeks prior to the testing to sensitize their nasal passages and to prevent colds. They were give a copy of the novel by Siskind called Parfum (Perfume) about smell to get them in the mood to appreciate smells and their importance in mate choice.

5) Females chose t-shirts of men with MHC genes that compared to their own in a particular way. What was it, and what was the explanation that the researchers offered for this result? (3 pts)

(1.5 points for what it was, and 1.5 points for the explanation)

Females preferred the odor of “mismatched MHC” or “different genes”(1.5 pt)

Explanation was that they were choosing mates (subconsciously) that were genetically different so that they would have a more diverse immune system and be better able to fight disease (viruses, bacteria). Full credit for “to have a more diverse immune system”.(1.5 pts).

1 point for “higher diversity” or “avoid inbreeding”

6) How did the women on birth control pills differ in their odor preference compared to the women who were not taking birth control pills? (2 pts)

Women on birth control pills did not show a preference for mismatched MHC genes. (full credit)

Additional information: women on the pill showed a preference (p=.05) for matched MHC genes, the opposite of what was found for women not on the pill. The researchers interpreted this as a tendency to want to be around relatives when pregnant and the pill simulates pregnancy. In studies with mice and MHC, mice are known to 1) prefer to mate with mismatched MHC males, and 2) prefer the odor of relatives when pregnant or nursing, presumably so that the relatives can help and be invested in the young surviving.