Chapter 7 Life History

Question 1

 An individual organism’s ___ _____ consists of major events related to its ___ _____ ___ and _____

Answer 1

life history

growth, development, reproduction, and survival.

Question 2

 ___ _____ ___ vary among individuals & populations and are influenced by natural selection.
 Life history traits like Timing, duration, phenology, rate, allocation, allometry, etc. are shaped by _____ ____

Answer 2

 Life-history traits

 natural selection

Question 3

 Life-history strategy is a _____-____representation.
 The life history strategy of a species is the overall pattern in the _____ and ____of life history averaged across all the individuals in the species.

Answer 3

 population-level

 timing and nature

Question 4

____ _____ occurs in asexual reproduction and produces ____ _____ ____

Answer 4

 Binary fission

genetically identical clones

Question 5

 Sexual reproduction produces ____ _____ ____

Answer 5

 genetically variable offspring

Question 6

 The production of equal sized gametes is called _____ . In most multicellular organisms however the two types of gametes are different sizes, a condition called _____ .

Answer 6

 isogamy.

anisogamy.

Question 7

 One cost of sexual reproduction: the asexual individual will _____ in number more rapidly, _____ out the sexual individual.

Answer 7

increase

wiping

Question 8

 Because meiosis produces _____ gametes that contain _____ the genetic content of the parent, a _____ reproducing organism can transmit only _____ of its genetic material to each offspring, whereas _____ reproduction allows transmission to the _____ genome.

Answer 8

haploid half
sexually half
asexual entire

Question 9

 recombination and the independent distribution of chromosomes into gametes (during meiosis) can disrupt ____ _____ ____, potentially reducing offspring fitness.

Answer 9

favorable gene combinations

Question 10

 the growth rate of sexuality reproducing populations is ____ _____ ____ of asexually reproducing ones, all else being equal.

Answer 10

only half that

Question 11

 Sex has some clear benefits, including _____ , which promotes _____ _____ and hence may increase the capacity of populations to evolve in response to environmental challenges such as drought or disease.

Answer 11

 recombination

genetic variation

Question 12

 Complex life cycle – 2 or more distinct stages that differ in ____ _____ or ____

Answer 12

 habitat, physiology, or morphology

Question 13

 Examples of complex life cycles: E.g., Alternation of Generations in plants; E.g., Holometabolous insects: Larval, pupal & adult wasps; E.g., Anadromous & catadromous fishes: Anadromous salmon adults live at sea, but spawn in freshwater; E.g., Metamorphic amphibians: Herbivorous, aquatic tadpole will become carnivorous, terrestrial adult.
 Diadromous – _____ (migrate from sea to freshwater to spawn) or _____ (migrate from freshwater to sea to spawn) life cycle.

Answer 13

 anadromous or catadromous

Question 14

 Separate life history stages can evolve _____ _____ .

Answer 14

somewhat independently.
 Ex of complex life cycle is that many organisms undergo metamorphosis, an abrupt transition in form from the larval to the juvenile stage that is sometimes accompanied by a change in habitat

Question 15

 Ontogenetic niche shifts Occur _____ in organisms with _____ life cycles, but occur in _____ organisms as well

Answer 15

routinely
complex
other

Question 16

 An allocation tradeoff is just like an ____tradeoff – a given amount of money spent on beer could not then be used to buy broccoli, and vice versa. Whether or not a particular life-history trait is favored by natural selection depends on the ___/____ ___
 Trade-offs occur when organisms ___ their limited energy or other resources to one structure or function at the ___ of another. Trade-offs among life history traits are common.

Answer 16

economic
benefit/cost ratio.
allocate
expense

Question 17

 Many organisms show a trade-off between their ____ in each individual offspring and the ____ of offspring they produce. Investment in offspring includes energy, resources, time, and the loss of chances to engage in alternative actives such as foraging.
 In many cases organisms that make a ____ investment in each offspring produce ____ numbers if large offspring, while organisms that make a ____ investment in each offspring produces ____ numbers of small offspring.

Answer 17

investment
number

large
small
small
large

Question 18

 Parental investment can also affect offspring quality as when ____ investment per offspring ____the risk of offspring mortality.

Answer 18

reduced

increases

Question 19

 Parental care is rare. In organisms that don’t provide parental care, resources invested in propagules (eggs, spores, seeds) are the main measure of reproductive investment.
 The ____ of the propagule is the ____ ____ of parental investment, and propagule ____is traded off against the ____of propagules produced in a reproductive bout.

Answer 19

size
primary measure
size
number

Question 20

 Allocation trade offs are more defined by a ____ ____ .
 That line is a constraint ceiling above which no one could ever fall because we’re starting with a finite resource. You can go below the line.

Answer 20

constraint line.

Question 21

 The “____” that is optimal under one set of circumstances is unlikely to be best suited to another set.

Answer 21

design

Question 22

 Semelparous vs. Iteroparous (Monocarpic vs. Polycarpic) Often entails a reproduction – ___ ____

____species reproduce only once in a lifetime, whereas ____species have the capacity for multiple bouts of reproduction.

Answer 22

survival tradeoff

Semelparous
iteroparous

Question 23

 R-selection and k-selection describes two ends of a ___ ____ ___ ____

Answer 23

continuum of reproductive patterns

Question 24

___- ____ is the “live fast, die young” and favors high and fast developmental rate, rate of maturation, and reproductive rate.

Answer 24

R-selection

Question 25

___- ____ is the “Slow & steady” and favors longer and larger body size, life span, and parental investment to offspring.

Answer 25

K-selection

Question 26

K-strategists are similar to ____ and r-strategists are similar to ____ .
Competitive plants are adapted to low stress low disturbance habitats.
Stress tolerant plants are adapted to high stress low disturbance habitats.
Ruderal plants are adapted to low stress high disturbance habitats.

Answer 26

Competitors

Ruderals

Question 27

“Lack Clutch Size” = clutch size that ____ the number

of ____ that a parent can rear to maturity, given the tradeoff between investment per offspring vs. number of offspring

Answer 27

maximizes

offspring