Ch. 7 Life History Analyses

Question 1

Social control of sex change

Answer 1

Clownfish

• If the female dies, the breeding male becomes a functional female
• next largest male becomes breeding male
• controlled by female aggression
• suppression of hormonal and neurotransmitter control of sex change in subordinate males
• breeding male cares for eggs until they hatch

Question 2

Sequential hermaphroditism

Answer 2

• protandry

- protogyny

Question 3

Protandry

Answer 3

Males first

Question 4

Protogyny

Answer 4

Females first

Question 5

There is a strict ___ or ___ ___ in the group, based on body size and aggression.

Answer 5

Social or dominance hierarchy

Question 6

Life history -

Answer 6

An organisms record of events relating to its growth, development, reproduction, and survival

Question 7

Characteristics that define organisms life history:

Answer 7

• age and size at sexual maturity
• amount and timing of reproduction
• survival and mortality rates

Question 8

Generalizations about a species life history traits can still be made but must consider ___.

Answer 8

Variations

Question 9

Life history strategy of a species:

Answer 9

• overall pattern in average timing and nature of life history events
• determined by allocation of time and energy between growth, reproduction, and survival

Question 10

___ are parts of a strategy

Answer 10

Traits

Question 11

___ refers to overall patterns at the species or population level.

Answer 11

Strategy

Question 12

Theoretically life histories are optimized by ___ ___.

Answer 12

Natural selection

Question 13

Phenotypic plasticity

Answer 13

• One genotype may produce different phenotypes under different environmental conditions
• many fishes develop different body shapes dependent on habitat
• pines grown in cool, moist climates allocate more biomass to leaf growth relative to sapwood production than do those in warmer desert climates

Question 14

Phenotypic plasticity may result in..

Answer 14

• continuous range of growth rates

- discrete types (morphs)

Question 15

Polyphenism -

Answer 15

Single genotype produces several distinct morphotypes

Question 16

Allometry -

Answer 16

Differential growth of body parts, resulting in differences in shape or proportion

Question 17

Asexual reproduction -

Answer 17

• simple cell division

- exhibited in all prokaryotes and many Protists

Question 18

Benefits of sexual reproduction:

Answer 18

• recombination promotes genetic variation
• increased ability of populations to respond to environmental challenges
• may provide protection against disease or changes in habitats

Question 19

Disadvantages of sexual reproduction

Answer 19

• “cost of males” - an individuals transmit only half of its genome to next generation
• growth rate of populations is slower

Question 20

C. elegans

Answer 20

• either male or hermaphrodite

- hermaphrodites can reproduce by self-fertilization (selfing) or mating with males (outcrossing)

Question 21

Isogamy -

Answer 21

When gametes are of equal size

Organisms such as the green alga produce isogametes

Question 22

Anisogamy -

Answer 22

Gametes of different sizes

Most multicellular organisms produce anisogametes

Question 23

Metamorphosis -

Answer 23

Abrupt transition in form from larval to juvenile stage

Question 24

Complex life styles -

Answer 24

Involve at least two distinct stages that may have different body forms and live in different habitats

Question 25

Why complex life styles?

Answer 25

Parents and offspring can be subject to different selection pressures

Butterfly

Question 26

Direct development -

Answer 26

Go from fertilized egg to juvenile without passing through a specific larval stage

Seepage salamander

Question 27

Alternation of generations:

Answer 27

• exhibited by plants and most algae

- multicellular diploid sporophyte alternates with a multicellular haploid gametophyte

Question 28

Reproductive patterns can be categorized along several continua.

Answer 28

Semelparous - iteroparous
r-selection - K-selection
Stress - disturbance
Charnov’s life history cube

Question 29

___ species reproduce only once.

Answer 29

Semelparous

Question 30

___ species can reproduce multiple times.

Answer 30

Iteroparous

Almond tree

Question 31

Semelparous species include:

Answer 31

• annual plants
• agave
• giant pacific octopus
• salmon

Question 32

Iteroparous species include:

Answer 32

• trees such as pines and spruces
• most plants and many herbaceous plants
• most vertebrates
• mane invertebrates
• Florida scrub jay

Question 33

r-selection and K-selection describe…

Answer 33

Two ends of a hypothetical continuum of reproductive patterns

Question 34

r =

Answer 34

Intrinsic rate of increase of population

Question 35

K =

Answer 35

Carrying capacity for a population

Question 36

r-selection is selection for…

Answer 36

High population growth rates in uncrowded environments, newly disturbed habitats, uncrowded contains, etc

Question 37

K-selection is selection for..

Answer 37

• slower growth rates in populations that are at or near K

- in crowded, more stable conditions, efficient reproduction is favored

Question 38

___ is a spectrum of population growth rates, from fast to slow.

Answer 38

r-K continuum

Question 39

On the r-selected end

Answer 39

• short life spans
• rapid development
• early maturation
• low parental investment
• high rates of reproduction
• most insects, small vertebrates such as mice, weedy plant species

Live fast, die young

Question 40

On the K-selected end

Answer 40

• long-lived
• slow development
• delayed maturation
• invest heavily in each offspring
• low rates of reproduction
• large mammals, reptiles such as tortoises and crocodiles, and long-lived plants such as oak and maple trees

Slow and steady

Question 41

Stress -

Answer 41

Any factor that reduces vegetative growth

Question 42

Disturbance -

Answer 42

Any process that destroys plant biomass

Question 43

“CSR” model

Answer 43

Competitive, stressed, ruderal