tesoke
Junior Member
- Joined
- Apr 7, 2015
- Member Type
- Student or Learner
- Native Language
- Persian
- Home Country
- Iran
- Current Location
- Iran
I cannot understand the correct answer. Would you please help. Thanks.
Reading:
Since Fisher‟s time, it has been realized that genes can sometimes influence the chromosome or gamete in which they find themselves so that the gamete will be more likely to participate in fertilization. If such a gene occurs on a sex-determining (X or Y) chromosome, then highly aberrant sex ratios can occur. But more immediately relevant to game theory are the sex ratios in certain parasitic wasp species that have a large excess of females. In these species, fertilized eggs develop into females and unfertilized eggs into males. A female stores sperm and can determine the sex of each egg she lays by fertilizing it or leaving it unfertilized. By Fisher‟s argument, it should still pay a female to produce equal numbers of sons and daughters. Hamilton, noting that the eggs develop within their host—the larva of another insect—and that the newly emerged adult wasps mate immediately and disperse, offered a remarkably cogent analysis. Since only one female usually lays eggs in a given larva, it would pay her to produce one male only, because this one male could fertilize all his sisters on emergence. Like Fisher, Hamilton looked for an evolutionarily stable strategy, but he went a step further in recognizing that he was looking for a strategy.
23. The passage contains information that would answer which of the following questions about wasps?
I.How many eggs does the female wasp usually lay in a single host larva?
II.Can some species of wasp determine sex ratios among their offspring?
III.What is the approximate sex ratio among the offspring of parasitic wasps?
(A) I only
(B) II only
(C) III only
(D) I and II only
(E) II and III only
Answer:
I think E is correct because II is true too. In the passage, the author says that there is only one offspring in parasitic wasps. A female do all thins things, reading says: "A female stores sperm and can determine the sex of each egg she lays by fertilizing it or leaving it unfertilized.", fertilizing all sperms except one of them. So, she know the ratio among her offspring. So, II is correct too.
Reading:
Since Fisher‟s time, it has been realized that genes can sometimes influence the chromosome or gamete in which they find themselves so that the gamete will be more likely to participate in fertilization. If such a gene occurs on a sex-determining (X or Y) chromosome, then highly aberrant sex ratios can occur. But more immediately relevant to game theory are the sex ratios in certain parasitic wasp species that have a large excess of females. In these species, fertilized eggs develop into females and unfertilized eggs into males. A female stores sperm and can determine the sex of each egg she lays by fertilizing it or leaving it unfertilized. By Fisher‟s argument, it should still pay a female to produce equal numbers of sons and daughters. Hamilton, noting that the eggs develop within their host—the larva of another insect—and that the newly emerged adult wasps mate immediately and disperse, offered a remarkably cogent analysis. Since only one female usually lays eggs in a given larva, it would pay her to produce one male only, because this one male could fertilize all his sisters on emergence. Like Fisher, Hamilton looked for an evolutionarily stable strategy, but he went a step further in recognizing that he was looking for a strategy.
23. The passage contains information that would answer which of the following questions about wasps?
I.How many eggs does the female wasp usually lay in a single host larva?
II.Can some species of wasp determine sex ratios among their offspring?
III.What is the approximate sex ratio among the offspring of parasitic wasps?
(A) I only
(B) II only
(C) III only
(D) I and II only
(E) II and III only
Answer:
I think E is correct because II is true too. In the passage, the author says that there is only one offspring in parasitic wasps. A female do all thins things, reading says: "A female stores sperm and can determine the sex of each egg she lays by fertilizing it or leaving it unfertilized.", fertilizing all sperms except one of them. So, she know the ratio among her offspring. So, II is correct too.
all-1) isn't really a ratio.
