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bio 251 > exam 3 > Flashcards

exam 3 Flashcards

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Biology 101 flashcards
1
Q

What are five costs of living in social groups?

A

competition for resources
more disease/parasite spread
groups easier to see/smell/hear
time/energy expended to deal with dominants
risk of inbreeding

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2
Q

what are 5 benefits of living in social groups?

A

organisms can find resources and share with the group (info center hypothesis); reduce competition.
assisted grooming (parasites, food when sick).
defense from predators (vigilance, dilution, mutual defense).
life insurance (genetic).
safety within group for subordinates.

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3
Q

what is the many eyes hypothesis

A

suggests that there are progressively more eyes scanning the environment for predators when group size increases.

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4
Q

what is the info center hypothesis

A

species live in communal roosts primarily for the advantage of gaining information from others in the community regarding the location of unevenly distributed food resources.

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5
Q

In what ways can honeybees provide evidence for the information center hypothesis?

A

When a worker discovers a good source of nectar or pollen (note the pollen spores dusting this bee’s back), she will return to the hive to perform a waggle dance to let her nest mates know where it lies. A bee performs the waggle dance when she wants to inform other bees of a nectar source she has found.

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6
Q

What are the four categories of helping behavior?

A

reciprocity (delayed benefit) (+/+)
mutualism (+/+)
facultative Altruism (only for a short period of time; very delayed) (+/+)
obligate altruism (+/-) (permanent loss of fitness/no offspring)

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7
Q

what is group selection theory

A

the logic of natural selection acting at the level of individual organisms can also be applied to the level of whole groups of organisms.

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8
Q

Why is group selection theory not a good explanation of the
evolution of altruism?

A

Examples of altruism, in which an individual performs an action that is costly to itself but benefits others (e.g. fighting an intruder), are better explained by kin selection, they argued.

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9
Q

what is kin selection theory

A

a process whereby natural selection favours a trait due to its positive effects on the reproductive success of an organism’s relatives, even when at a cost to the organism’s own survival and reproduction. Kin selection can lead to the evolution of altruistic behaviour.

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10
Q

What does inclusive fitness mean within the context of kin selection theory?

A

Inclusive fitness suggests that altruism occurring among organisms who share a given percentage of genes enables those genes to be passed on to subsequent generations. Inclusive fitness applying only to relatives is called kin selection.

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11
Q

What does the coefficient of relatedness (r) measure and how is it calculated?

A

a measure of the probability that two individuals share the same allele via a recent, common ancestor, and thus it is “identical by descent”. It is the sum of the coefficients.

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12
Q

What is the coefficient of relatedness between: (1) half siblings, (2) full siblings,
(3) first cousins?

A

.25
.5
.125

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13
Q

what is Hamilton’s rule

A

rB>C
predicts that social behaviour evolves under specific combinations of relatedness, benefit and cost.
If C is cost of helping, and B is benefit, helping will evolve by natural selection is rB>C

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14
Q

Hypothetically, should you sacrifice to save two sisters or nine cousins?

A

2(.5)=1.0
9(.125)=1.125
C=1
9 cousins

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15
Q

what is sexual selection

A

the advantage of which certain individuals have over others of the same sex and species in exclusive relation to reproduction

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16
Q

examples of sexual selection

A

peacocks with larger/colorful tails will mate more frequently.
fruit flies perform dances for mates
penguins give their potential mate rocks

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17
Q

intrasexual selection

A

part of sexual selection where members of the same sex (males) compete with each other to gain access to mate with females. (sexual dimorphism)

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18
Q

intersexual selection

A

occurs as a result of interactions between males and females of a species. One sex, typically males, will develop and display traits or behavior patterns to attract the opposite sex.

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19
Q

Why are females generally disinclined to mate, but males are always eager to mate?

A

females can only get pregnant once at a time, and have high parental investment. females are born with a certain number of eggs.

males have more chances to mate and have a low rate of parental investment. males can produce more sperm throughout their lifetime.

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20
Q

What are the four types of mating systems found in nature?

A

polygyny, promiscuity, monogamy, polyandry

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21
Q

what is polygyny

A

a male animal has more than one female mate (elephant seals)

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22
Q

what is promiscuity

A

A mating system in animals where they pair with a mate for one mating season but change mates over the course of a lifetime (bonobos)
occurs in unpredictable habitats

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23
Q

what is monogamy

A

a mating system of one male and one female forming an exclusive social pair bond (swans)
needed mate assistance and guarding.
female enforced

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24
Q

polyandry

A

a female animal has more than one male mate (pipefish).
male is primary caregiver

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25
Q

What are 3 strategies that males use to attract and acquire females?

A

fighting other males for a female
mate guarding (anti-aphrodisiac)
sperm competition (sperm removal tools; large testicles)

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26
Q

What are 3 strategies that females use to choose males?

A

material choice benefit (males defending territory w/ resources; nuptial gifts/courtship feeding).
non-material benefit choice (ornaments and displays).

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27
Q

what are the 3 hypotheses proposed for the non-material benefits female mate choice.

A

healthy mate, good genes, runaway selection.

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28
Q

what is the healthy mate hypothesis

A

females want a male mate who is healthy to prevent herself and her offspring from getting diseases/parasites.

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29
Q

what is the good genes hypothesis

A

females want their offspring to inherit the viability advantages of the father.

30
Q

what is the runaway selection hypothesis

A

sons inherit traits that will make them attractive to females.
daughters will inherit majority of mate preference.

31
Q

What benefits do females gain in non-material benefits mate choice?

A

increased territory quality, increased parental care, and protection from predators.

32
Q

Why is the sex ratio in many populations at 50:50 when in fact not all males get to mate?

A

there are equal numbers of X and Y chromosomes in mammalian sperm. X and Y stand equal chance of achieving conception. therefore equal numbers of male and female zygotes are formed. therefore any variation of sex ratio at birth is due to sex selection between conception and birth.

33
Q

5 factors affecting species richness

A

time: for NS/colonization.
geographic: latitude, altitude, depth; larger area means more biodiversity.
productivity: energy availability
disturbance: isolation; physical and chemical heterogeneity.
biological: predation, parasitism, competition.

34
Q

what is the time hypothesis

A

explains latitude gradient; proposes that species richness is linked to the ages of clades.
Ice age and tropical areas

35
Q

what is the area hypothesis

A

larger areas support more species

36
Q

what is the productivity hypothesis

A

the more energy there is in a system, the more biomass there will be in that system. More biomass supports greater species diversity.

37
Q

what is the latitudinal gradient

A

The pattern of having lots of species at the equator with diversity dwindling off towards the poles

38
Q

shannon diversity index equation

A

H = -å Pi(lnPi)
Pi= abundance of spp/total
a=sum of

39
Q

What is the species area effect?

A

larger islands have more species than smaller ones

40
Q

what is species distance effect

A

islands closer to a source should have more species

41
Q

what is island biogeography theory

A

predicts that species diversity on an island is positively related to the size of the island, but negatively related by the island’s distance to the mainland.

42
Q

What are three reasons why the species area relationship might not be sufficient to
predict extinction rates?

A

assumes all species are eliminated during habitat clearing (species adapt and survive in conditions).
assumes habitats are eliminated at random (high diversity areas are protected).
Fragmentation extent affects extinction rates.

43
Q

does SAR over- or under-estimate species richness

A

overestimate

44
Q

what is ecosystem ecology

A

the study of interactions of organisms with the transport and flow of energy and matter

45
Q

what do ecosystems include

A

organisms and their abiotic environment; boundaries.

46
Q

types of ecosystems

A

forest, desert, rain forest, grassland, tundra, savanna and mountain ecosystem.

47
Q

What are the main differences between a food web and food chain?

A

A food chain outlines who eats whom. A food web is all of the food chains in an ecosystem.

48
Q

How is a terrestrial food chain different from an aquatic food chain?

A

In terrestrial ecosystems, the dynamics of producers (e.g. long lived grasses and trees) often occur on timescales much longer than the dynamics of their herbivores (e.g. insects and mammalian herbivores), whereas in aquatic ecosystems the dynamics of producers (e.g. algae) often occur at timescales shorter than their consumers (e.g. invertebrate grazers). This could perhaps explain why terrestrial ecosystems typically exhibit trophic pyramids (i.e. the standing biomass of plants is higher than that of herbivores), whereas sometimes this pyramid is inverted in aquatic ecosystems

49
Q

How is a terrestrial food chain different from a detrital food chain?

A

GFC begins with the producers as first trophic level whereas DFC begins with detritivores and decomposers as first trophic level. In GFC, energy comes from the sun whereas in DFC, energy comes from detritus or organic remains.

50
Q

how many links do food webs usually have

A

3-4

51
Q

Why are chain lengths usually so short?

A

less and less energy is available to animals at higher levels in the food chain.

52
Q

What is an inverted ecological pyramid and how would one form?

A

formed when the number of individuals or biomass is minimum and increases at each trophic level. The pyramid of biomass in a pond ecosystem is an example of an inverted pyramid because the biomass of phytoplankton may be smaller than that of zooplankton.

53
Q

what is a ecological pyramid

A

a graphical representation of the energy found within the trophic levels of an ecosystem. The bottom and largest level of the pyramid is the producers and contains the largest amount of energy.

54
Q

Consumption Efficiency

A

the consumer’s success in obtaining the greatest level of consumption from a given set of resources.
In/Pn-1

55
Q

assimilation efficiency

A

The ratio of the amount of food absorbed (i.e. assimilated) to the total food ingested by an animal.
An/In

56
Q

production efficiency

A

the storage of biomass and efficiency is that fraction of biomass consumed that actually ends up being stored, i.e., stored as an organism’s body, minus that amount lost as feces.
Pn/An

57
Q

trophic transfer efficiency

A

the efficiency at which mass (or energy) is transferred from one trophic level to the next through predation.
Pn/Pn-1

58
Q

chemical equation of photosythesis

A

6CO2 + 6H2O → C6H12O6 + 6O2

59
Q

what factors most influence photosynthesis?

A

The main factors affecting rate of photosynthesis are light intensity, carbon dioxide concentration and temperature.

60
Q

what factors limit photosynthesis in aquatic ecosystems

A

limited light, nutrients, and grazing

61
Q

What is the difference between net primary production and gross primary production?

A

Gross primary production (GPP) is the total rate at which material is produced and net primary production (NPP) is the the amount of biomass or carbon produced by primary producers per unit area and time

62
Q

What is the relationship between Evapotranspiration and primary production?

A

Annual AET(sum of water that evaporates and transpires off a landscape during the course of a year) is positively correlated with net primary production because the highest rates of terrestrial PP occurs under warm and moist conditions.

63
Q

What are the multiple levels at which biodiversity occurs?

A

genetic diversity within a population.
species diversity.
community/ecosystem diversity.

64
Q

What are three reasons why we must conserve biodiversity?

A

humans depend on plants/animals/micro for goods.
ecosystems and species within an ecosystem provide a variety of free essential services.
humans have an ethical responsibility to protect creation.
FOOD SECURITY

65
Q

where does 90% of human food come from

A

15 crops and 8 livestock species

66
Q

What is the relationship between biodiversity and food security?

A

less biodiversity means less of the plants, animals and microorganisms that are critical to pollination, cleaning water and keeping soil fertile.

67
Q

What is the relationship between biodiversity and pharmaceuticals?

A

50,000-90,000 plant species used in traditional and modern medicine.
About 119 pure chemicals come from plants (caffeine, methyl salicylate, quinine).
Antibiotics from fungi.
Variety of animal products (horseshoe crab blood).

68
Q

What are the five primary causes of biodiversity loss?

A

Climate change.
Pollution.
Destruction of habitats.
Invasive alien species.
Overexploitation of the natural environment.

69
Q

diversity stability hypothesis

A

having multiple species present in a plant community can stabilize ecosystem processes if species vary in their responses to environmental fluctuations such that an increased abundance of one species can compensate for the decreased abundance of another.

70
Q

redundancy hypothesis

A

the enhancement of species that can compensate each other if some species loss due to harsh conditions such particular species has the ability to recover from environmental disturbances

71
Q

keystone hypothesis

A

certain species (or groups) can exert an influence on the ecosystem within which they live, that is out of proportion to their abundance or biomass.

72
Q

idiosyncratic hypothesis

A

changing the number of species influences ecosystem processes, but no obvious pattern is evident; hence, the role of biodiversity is unpredictable.

bio 251 (1 decks)

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