Metabolism and Survival - Conformers and Regulators

Question 1

conformer

Answer 1

• an organism whose internal environment is directly dependant upon its external environment
• these organisms are unable to maintain their metabolic rate through physiological responses
• they use behavioural responses to maintain optimum metabolic rate
• they have low metablic costs
• they have a narrow range of ecological niches

Question 2

ectotherm

Answer 2

animal which is unable to regulate its body temperature through physiological means

Question 3

effector

Answer 3

a muscle or gland which performs the body’s response to stimuli following the receipt of signals from the nervous system

Question 4

endotherm

Answer 4

animal which is able to regulate its body temperature through physiological means

Question 5

hypothalamus

Answer 5

region of the brain which is the body’s temperature monitoring centre

Question 6

negative feedback control

Answer 6

a change in a physiological factor is sensed by receptors which sends messages to the effectors to trigger a corrective response to bring the factor back to its norm

Question 7

physical homeostasis

Answer 7

the maintenance of the body’s internal environment within certain tolerable limits despite changes in the body’s external environment

this regulation is brought about by negaitve feedback control

Question 8

regulator

Answer 8

• an organism which can maintain their internal environment regardless of the external environment
• they maintain a steady state of homeostasis which requires energy
• they have high metabolic costs
• the can exploit a wide range of exological niches

Question 9

thermoregulation

Answer 9

maintenance of a mammal’s internal body temperature within certain tolerable limits

Question 10

corrective responses to overheating

Answer 10

• vasodialation - increased blood flow near surface of skin inreases heat loss through radiation
• increased sweating - body heat evaporates water in sweat, cooling the skin
• relaxation of hair erector muscles - prevents heat being trapped in a layer of air next to the skin
• decrease in metabolic rate - reduces heat produced

Question 11

corrective responses to overcooling

Answer 11

• vasoconstriction - reduces blood flow near the surface of the skin decreasing heat loss through radiation
• decreased sweating - reduces heat loss by evoporation
• contraction of hair erector muscles - traps a layer of insulating air to reduce heat loss
• increased metabolic rate
• shivering - contraction of muscles generates heat