Ecology Chapter 9

D

Although many species of birds were thought to be strictly monogamous, this idea has been challenged recently by the discovery that __________ are quite common. A) hermaphroditic individuals B) intergeneric matings C) female‐biased sex ratios D) extra‐pair copulations

E

Asexual reproduction is found in all major groups of animals except: A) hydroids. B) corals. C) insects. D) fishes and reptiles. E) birds and mammals.

C

Asexual reproduction is quite common in plants. Most plant cells retain the ability to produce an entire new individual, as is the case when new shoots sprout from roots or rhizomes, or even the margins of leaves. Such asexual reproduction is referred to as: A) parthenogenesis B) selfing C) vegetative reproduction D) asexual selection

B

Because the process of asexual reproduction does not involve genetic contributions from two individuals, meiosis is never involved. A) True B) False

C

Compared to their hosts, pathogens typically evolve: A) more slowly. B) at about the same rate. C) more rapidly. D) None of the above—pathogens are incapable of evolving.

B

Curt Lively and coworkers at Indiana University have studied coevolution between snails and their trematode worm parasites. They found that when the prevalence of infection was high: A) males made up about 50% of the populations, indicating that all reproduction was sexual. B) males were common, indicating relatively high rates of sexual reproduction. C) males were uncommon, indicating relatively low rates of sexual reproduction. D) males were absent, indicating a lack of sexual reproduction.

D

Support for the Hamilton‐Zuk hypothesis has come from which of the following observations? A) Male elk with larger antlers often defeat males with smaller antlers. B) Larger male elephant seals are more successful in establishing harems. C) Male cardinals with larger territories are more likely to attract multiple mates. D) Female feral rock doves preferred clean to parasite‐infested males by a ratio of 3:1.

haploid

The __________ cell products of meiosis contain a full complement of chromosomes, but contain only one member of each chromosome pair present in diploid cells

D

The bdelloid rotifers are unusual in that they are a moderately diverse group of organisms that seems to have reproduced only asexually for tens of millions of years. How have these species maintained diversity in their gene pool? A) by occasional sexual reproduction B) by occasional hybridization with other kinds of rotifers C) by living in unvarying environments D) by maintaining altered copies of a duplicated gene that code for functionally different proteins

A

The high fitness cost of sexual reproduction may be offset by the advantage of producing genetically varied offspring because the environment itself varies over time or space. A) True B) False

B

The progeny of a sexual union contribute only one‐half as much to the evolutionary fitness of either parent as asexually produced offspring. This relative reduction in fitness is called __________. A) the Red Queen hypothesis B) the twofold cost of meiosis C) sequential hermaphroditism D) dioecism

E

The progeny produced by sexual reproduction are: A) genetically different from one another. B) genetically different from their parents. C) genetically identical to one another. D) genetically identical to their parents. E) Both A and B are correct. F) Both C and D are correct.

handicap

The wheatear, a small European songbird, decorates its nesting ledge with up to 2 kg of small stones in a display that seems a perfect example of the __________ principle of sexual selection proposed by Israeli biologist Amotz Zahavi.

C

Under which of the following conditions is hermaphroditism likely to arise in a species in which the individuals have only one sexual function (male or female)? A) Adding male function results in a proportionately smaller loss of female function. B) Adding female function results in a proportionately smaller loss of male function. C) both A and B D) neither A nor B

D

Under which of the following conditions would you expect to find local mate competition? A) Individuals do not disperse far from where they were born. B) Mating takes place among close relatives. C) Mating takes place among the progeny of an individual female. D) all of the above

D

Curt Lively and coworkers found that four common clones of snails from a shallow lake in New Zealand varied in abundance over a four‐year period; increases in population size of any particular clone were followed by marked increases in the rate of parasitism. What evolutionary process was responsible for these phenomena? A) balancing selection B) directional selection C) purifying selection D) frequency‐dependent selection

runaway

Female preferences in mate selection can lead to the evolution of seemingly outlandish ornamentation and displays among males in a process that has been dubbed __________ sexual selection.

C

From a phylogenetic perspective, asexual species of complex animals (fishes, amphibians, reptiles): A) appear to have a long evolutionary history. B) belong to genera in which many other species are also asexual. C) probably do not persist for long periods. D) All of the above are true.

C

Hamilton and Zuk proposed in 1982 that showy plumage in males might provide individuals having superior genotypes an opportunity to display which trait to potential mates? A) great physical strength B) superior intelligence C) resistance to parasites D) extended life span

D

Having separate sexes is favored when individual gains in fitness from adding a second sexual function bring about even greater losses in the original sexual function. Such would be the case when: A) adding either sexual function requires additional complex anatomical structures. B) maleness requires specializations for mate attraction and combat with other males. C) femaleness requires specializations for egg production or brood care. D) all of the above

monoecious

Hermaphroditic plant species that have, on the same individual, separate flowers having male or female sexual function are referred to as __________.

A

Hermaphroditic snails and most worms typically exhibit __________ male and female sexual functions. A) simultaneous B) sequential C) partial D) dioecious

Charles Darwin

In 1871,__________ published a book entitled The Descent of Man and Selection in Relation to Sex, in which he was the first to propose the idea of sexual selection.

B

In a species with an XY sex determination system, the only possible outcome is a 50:50 male:female sex ratio. A) True B) False

C

In gynodioecious plants, hermaphrodites and females exist in the same populations. In many such cases, the genes that cause male sterility (and thus result in plants that are essentially female) are transmitted only through female gametes, because such genes are found in the __________. A) pollen B) nucleus C) cytoplasm, within chloroplasts D) cytoplasm, within vacuoles

B

In several species of turtles, lizards, and alligators, sex of an individual is determined by: A) the social environment. B) the temperature at which it develops in the egg. C) the female parent. D) the male parent.

B

In species with separate sexes, which sex can enhance more its evolutionary fitness by mating with many partners of the opposite sex? A) females B) males C) Neither sex has an advantage in this respect.

C

In the California sheephead, heavy fishing has resulted in which of the following? A) earlier age at maturity B) earlier age of sex switching from female to male C) both A and B D) neither A nor B

zygote

In the typical process of sexual reproduction, gametes from two individuals unite to form a single cell called a __________.

B

In which of the following groups are there haplodiploid species, in which females can control the sex ratio of their offspring by storing sperm and using it—or not—to fertilize their eggs? A) all insects B) hymenopterans (bees, ants, and wasps) C) all vertebrates D) birds E) mammals

secondary

Individual traits that advertise an individual's sex but that are not related to the primary sexual organs are called __________ sexual characteristics.

A

Most cases of asexual reproduction in complex animals (fishes, amphibians, reptiles) appear in species that belong to genera in which other species are sexual. This sporadic distribution of asexual reproduction indicates that: A) the long‐term evolutionary potential of asexual species is low. B) the long‐term evolutionary potential of asexual species is high.

B

Of the two possible kinds of polygamy, which is by far the more common in animals? A) polyandry (one female forms long‐term bonds with more than one male) B) polygyny (one male forms long‐term bonds with more than one female)

A

Part of the fundamental asymmetry of life in species having separate sexes is that __________ typically exercise the greater degree of choice in selection of mates. A) females B) males

dimorphism

Sexual __________ is the usual outcome of sexual selection.

B

What did Curt Lively and coworkers find when they experimentally infected populations of snails taken from various depths in a lake, using trematode worm parasites also taken from various depths? A) Snails taken from a particular depth were most readily infected by parasites from other depths. B) Snails taken from a particular depth were most readily infected by parasites from the same depth. C) Snails taken from a particular depth were infected about equally well by parasites from any depth. D) There was a surprising lack of infection in any of the experimental combinations of snails and parasites.

A

What happened when the tails of male widowbirds were artificially elongated? A) These males were more successful in attracting mates than males with normal tails. B) These males were less successful in attracting mates than males with normal tails. C) These males were about equally successful in attracting mates as males with normal tails.

A

What is the key evolutionary concept underlying the Red Queen hypothesis? A) Through sex and genetic recombination, hosts present a moving target for evolving pathogens. B) Through sex and genetic recombination, hosts prevent evolution of pathogens. C) Through sex and genetic recombination, hosts are able to stop evolving and still maintain high fitness. D) All of the above are true.

C

Which of the following describes the predominant condition in flowering plants? A) Most plant species are monoecious. B) Most plant species are dioecious. C) Most plant species are perfect‐flowered hermaphrodites. D) Most plant species have both hermaphrodites and either male or female individuals.

D

Which of the following groups would you study if you were interested in finding species with female‐biased sex ratios? A) corals B) large mammals C) insectivorous birds D) parasitic wasps E) any species living exclusively on small islands

E

Which of the following plant species would be considered hermaphroditic? A) one that is strictly dioecious B) one that is strictly monoecious C) one that has only perfect flowers D) A and B E) B and C

B

Which of the following will exactly negate the cost to a female of sexual reproduction? A) Male parental investment halves the number of offspring that a female could rear on her own. B) Male parental investment doubles the number of offspring that a female could rear on her own. C) Male parental investment triples the number of offspring that a female could rear on her own. D) Male parental investment quadruples the number of offspring that a female could rear on her own.

C

You are studying a species of bird that is often monogamous but sometimes exhibits polygyny. You have the choice of studying this species in several different habitats. Which of the following will you choose if you want a high probability of finding polygyny? A) a habitat in which territory qualities are nearly identical B) a habitat in which territory qualities vary somewhat C) a habitat in which territory qualities are highly variable D) a habitat unsuitable for the formation of territories

corals

__________ are marine animals that reproduce asexually, often forming massive undersea colonies.

mate guarding

__________ is a common phenomenon in male birds faced with the constant threat of extra‐ territorial copulations.