Sub 10: Conformers and Regulators

Question 1

what do we call the ability of organisms to maintain a constant internal environment in the face of constant changes in the external environment?

Answer 1

homeostatis

Question 2

what is stress?

Answer 2

physiological condition where the level of an environmental condition or resource is outside the optimum range for that organism

Question 3

what are the adaptations for organisms living with constant wave action?

Answer 3

strong means of attachment - holdfasts
physically resistant body structure - shell
behavioural - settle in cracks between rocks

Question 4

what are the adaptations for organisms living in the arctic and antarctic habitats?

Answer 4

large body size to give small surface area to volume ratio to reduce heat loss through radiation
thick coat and layer of blubber
white coat to blend into environment

Question 5

what is vasoconstriction?

Answer 5

when surface capillaries constrict and get narrower

Question 6

what is vasodilation?

Answer 6

capillaries dilate for rapid heat loss

Question 7

why does a plant wilt?

Answer 7

cause the leaf surface to be removed from direct sunlight and can prevent plant overheating and reduce transpiration rate

Question 8

what is a regulator?

Answer 8

regulators are able to maintain their internal environment regardless of the changes in the external environment

Question 9

why do regulators require more energy than conformers?

Answer 9

regulators use up a lot of energy in maintaining their internal environment so more food is required more frequently
conformers have more energy available fro growth and reproduction

Question 10

do regulators or conformers have greater freedom of movement?

Answer 10

regulators as they are least affected by environment temperature

Question 11

what are conformers?

Answer 11

conformers do not maintain a constant internal environment, it changes with the external environment

Question 12

what is osmoregulation?

Answer 12

mechanism by which organisms maintain a constant water balance within their cells

Question 13

give examples of osmoconformers

Answer 13

shrimp, crabs and jellfish

Question 14

what are osmoconformers?

Answer 14

their body fluids are isotonic with their environment

Question 15

what are osmoregulators?

Answer 15

body fluids are not isotonic with the environment

Question 16

what are poikilotherms and homeotherms?

Answer 16

poikilotherm - body temperature varies with the surrounding environment e.g. snake
homeotherm - maintain a constant body temperature e.g. humans

Question 17

what is body temperature monitored by

Answer 17

the hypothalamus in the bottom of the brain

Question 18

what is temperature changes detected by initially?

Answer 18

nerve cells in the skin

Question 19

what are behavioural methods of thermoregulation?

Answer 19

resting in s cool burrow to avoid the heat of the day
migrating
basking on rocks to absorb heat from sun
cooling down in water

Question 20

what is dormancy?

Answer 20

a period when the organisms metabolism is reduced promoting survival during adverse conditions

Question 21

what is predictive dormancy?

Answer 21

allows dormancy to occur before the onset of adverse conditions in habitats where the change occurs in a regular way

Question 22

what is consequential dormancy?

Answer 22

allows the organism to react immediately to environmental cues. organism enters a state of dormancy after they have been exposed to adverse conditions

Question 23

what is the disadvantage of consequential dormancy?

Answer 23

sudden changes in conditions may result in high mortality rates

Question 24

what is the advantage of consequential dormancy?

Answer 24

dormancy is delayed until adverse conditions arise, meaning that the organism can make use of the resources available in the habitat for as long as possible

Question 25

name all types of dormancy

Answer 25

torpor
diapause
hibernation
aestivation
resting pores

Question 26

what is torpor?

Answer 26

reduction in body temperature to an ambient temperature when inactive during the day

Question 27

what is diapause?

Answer 27

predictive dormancy - suspension of development in insects.

Question 28

what is hibernation?

Answer 28

period of longterm inactivity in animals. lower metabolic rate

Question 29

what is aestivation?

Answer 29

consequential dormancy entered into by organisms in response to very hot, dry conditions

Question 30

what are resting spores?

Answer 30

consequential dormancy - when hard cases surrounds the dehydrated content of the seed or spore

Question 31

describe the tolerance curve

Answer 31

there is an optimum range within which the performance of the organism reaches a maximum.
between the upper and lower limits, the performance decreases
beyond the limits the organism cannot survive

Question 32

what is the clutch size?

Answer 32

the number of offspring produced at each reproductive episode

Question 33

what is the differences between r and k selected species?

Answer 33

r selected - rapid development, small adult size, many small offspring, short generation time
k selected - slow development, large adult size, few, large offspring, long generation time

Question 34

why are r and k selected species the way they are?

Answer 34

r selected are adapted to maximise the rate of increase of population size
k selected are adapted to be competitive

Question 35

what is a survivorship curve?

Answer 35

expresses the age distribution of a population and can be used to predict future population numbers