ecology lec 5 defs

Question 1

Reproductive Strategies-Asexual reproduction

Answer 1

organisms produce offspring that are clones of the parent (bacteria, some insects (wasps, bees, ants) , some plants-not flowers, some algae)

Question 2

Reproductive Strategies-Sexual reproduction

Answer 2

organisms reproduce via 2 parents offspring are a combination of genetic material from both parents; increases genetic diversity (mammals (see K selected) and flowering plants (angiosperms)

Question 3

Reproductive Strategies-2 different strategies

Answer 3

r & K selection

Question 4

r-selection

Answer 4

The two evolutionary “strategies” are termed r-selection, for those species that produce many “cheap” offspring and live in unstable environments and K-selection for those species that produce few “expensive” offspring and live in stable environments.

Question 5

r-selected species

Answer 5

species with a capacity for a high rate of population increase; many, small, no parental care, high mortality early in life, maturity = early, environment = unstable (cheap/uncomplicated offspring

Question 6

r-selected species examples

Answer 6

1) algae/bacteria, 2) pest organisms insects, rodents, & weeds. 3) Fish & frogs

Question 7

K-selected species

Answer 7

species that tend to reproduce late in life, but spend more time caring for their offspring; few, large offspring, parental care, low mortality early in life, environment = stable (expensive/complicated offspring), maturity=late.

Question 8

K-selected species example

Answer 8

1) primates humans 2) elephants 3) whales 4) extinction long times between generations & low reproductive rates Polar bears, rhino, sharks.

Question 9

How are populations regulated

Answer 9

some are stable, some are cyclic

Question 10

stable population pattern

Answer 10

A stable population fluctuates slightly above and below carrying capacity and is characteristic of many species living under fairly constant environmental conditions. e.g. tropical rain forests where avg temp & rainfall vary little from year to year

Question 11

cyclic population patterns

Answer 11

Cyclic fluctuations occur over a regular time period, generally a multiple year cycle. e.g. sync and hare whose populations generaly rise & fall in 10 year cycles.

Question 12

top-down regulation

Answer 12

these populations are controlled by the feeding level above them (usually predators BUT can be parasites, predators or competitors ). abundances of organisms at lower trophic levels can be strongly affected

Question 13

bottom-up regulation

Answer 13

these populations are controlled by the feeding level (trophic level) below them (usually food or nutrients). Remember organism is part of a larger community which controls its ability to grow or shrink. Bottom-up controls arise from near the bottom of the food web, below the trophic level in question. Exp. Plants = nutrients,water sunlight (give fertilizer to bulk up nutrient content) abiotic factors

Question 14

mutualism

Answer 14

an interaction between two organisms of different species that is beneficial for both organisms (e.g. honeybee and flower honeybee gets food (nectar and pollen) and the flower gets pollinated (reproduces). Oxpeckers & rhinoceros -

Question 15

mutalism examples

Answer 15

exp1: combine nutrition and protection:oxpeckers - eat parasites (ticks/flies) from rhinoceros. oxpeckers make noises warning the larger animals predator approch. exp2: clownfish, live sea anemones, tenetacles sting/paralyze fish. gain protection and feed on detritus lef from anemones meal. clownfish protect anemones predators/parasites

Question 16

commensalism examples

Answer 16

epiphytic plant in tree | birds nesting trees, barnacles on whales

Question 17

commensalism

Answer 17

an interaction between two organisms that is beneficial for one organism and neutral for the other organism (e.g. epiphytic plant that lives on a branch of a tree in the rainforest it benefits by being closer to the sun and away from the ground; the tree is unaffected)

Question 18

competition

Answer 18

an interaction between two organisms that is detrimental for both organisms (two hyenas fighting over the carcass of a dead animal; or a hyena and a turkey vulture fighting over the carcass of a dead animal). Conflict arises due to using same limited resource in the same ecosystem.

Question 19

exp of limited resource that cause competition

Answer 19

space, water (eucaplytus tree steals), light (rainforest), nutrients, food, nesting sites , mates

Question 20

predation

Answer 20

interaction between in which one organism of one species (predator) feeds on organism of another species (prey). an organism killing and eating another organism (the prey. Beneficial for one organism and detrimental for the other organism. e.g. lion eating an antelope OR wolf eats elk )

Question 21

examples predation

Answer 21

wolf eating elk | lion eating antelope | croccodile eating wildebeest

Question 22

parasitism

Answer 22

interaction between species in which one organism called parasite, preys on another organism called host by living on or in the host. an organism feeds on another organism, but rarely kills it –beneficial for one organism and detrimental for the other organism (e.g. mosquito)

Question 23

exp parasitism

Answer 23

A flea is a parasite on a coyote. The flea benefits by drinking the coyote’s blood, but the coyote, by losing blood and acquiring discomfort and potential disease, is harmed. 2) mosquito feeds on blood, possible giving diseases to human.

Question 24

inter-specific competition

Answer 24

two individuals from different species that are competing for the same limited resource (food, water, light, nutrients, space , nesting)

Question 25

top-down and bottom-up regulations together

Answer 25

Top-down (consumer) regulatory processes are said to occur when, for example, predators keep prey populations at levels below the population size that would be observed in the absence of predators. If on the other hand, factors such as food and/or habitat availability are the main drivers explaining population fluctuations, a population is said to be regulated by bottom-up (resource) regulatory processes. Populations can also be regulated by both processes, either through a seasonal shift from one process to the other, or when both processes act in concert.

Question 26

top down and bottom up Community Ecology

Answer 26

The structure of a community may be controlled from the bottom up by nutrients or from the top down by predators.
-top-down trophic model predicts changes in density at one trophic level caused by opposite changes in the next higher trophic level, and such inverse correlations cascade down the food chain.

Question 27

what are issues with asexual species

Answer 27

no genetic variation->vulnerable to say fungus outbreak like that which occurred 1950 ireland potato famine. today Gros Michel banana 1960 wiped out type fungus. now cavendish bananna has disease. [strawberries, sour grass have underground runners]

Question 28

populations generally regulated by abiotic factors are

Answer 28

generally insects (r-selected) | weather | space | nesting

Question 29

populations generally regulated by biotic factors

Answer 29

generally large animals (K selected) [ predators above them or food below]