Temperature Regulation Revision

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1

True or False:Q. Some plants can use their metabolism to

warm themselves up when the ambient temperature drops.

A. True

2

True or False:Q. Ambient temperature relates to the

temperature outside.

A. False.

3

True or False:Q. Blood clotting is an example of a negative

feedback loop.

A. False.

4

True or False:Q. Receptors are sensory cells.

A. True.

5

True or False:Q. Interoreceptors are sensors sensitive to

internal stimuli

A. True.

6

True or False:Q. Homeostasis is only achieved when variables

are operating at the set point.

A. False.

7

Q. What two systems do mammals use to maintain homeostasis?

A. Endocrine system and the nervous system.

8

Q. Explain what thermoreceptors and chemoreceptors detect.

A. Thermoreceptors detect internal changes in temperature. They are present inside and outside the body. Chemoreceptors detect the concentration of certain chemicals inside the body.

9

Q. Provide an accurate definition of torpor.

A. Torpor - short term hibernation.

10

Q. Provide an accurate definition of brown fat.

A. Some endotherms have this special type of tissue which once metabolised, produces heat. It can be metabolised quickly in cold conditions.

11

Q. Identify two responses of plants to temperature change.

A. Transpiration, turgor response (wilting), leaf orientation, leaf fall, reseeding and resprouting in response to fire, thermogenic plants, organic anti-freeze, dormancy and vernalisation.

12

Q. Distinguish between the endotherms and ectotherms below.

A. endo, ecto, ecto, endo, endo, ecto.

13

Q. Explain the differences in endotherms and ectotherms.

A. Endotherms – an organism that produces heat through internal means, such as muscle shivering or increasing its metabolism.

Ectotherms - organisms which depend on an external source (the environment) for heat energy.

14

Q. Identify 3 environments (that vary in temperature) where life can be found. Identify 3 organisms that cannot survive in each of these environments.

A. Desserts, Icy environments, hydrothermal vents etc. Bears, elephants , penguins.

15

Q. What is a substrate? What is a enzyme? Explain what is meant by substrate specific.

A. A substrate is the molecule on which an enzyme acts upon. Enzymes are protein molecules, present in cells, which act as biological catalysts, controlling the rate of each step of the complex chemical reactions that take place in cells. Enzymes only act on one type of substrate.

16

Q. Spell the 4 words read out by the teacher.

A. Catabolic, receptors, peripheral, interoreceptors.

17Q. Identify the pH as a way of describing the

acidity of a substance. What level do most cells function at? What happens if the pH fluctuates outside its normal range?

A. pH is the measure of the acidity or alkalinity of a substance. If a substance is a strong base it has a pH level of 14 if a substance is a strong acid it has a pH level of 0. Most cells function at or near neutral. If the pH fluctuates outside its normal range the enzyme will begin to denature.

18Q. Outline the role of the nervous system in detecting

and responding to environmental changes (Hint there is 7 stages).

A. Stimuli, receptors, messengers, CNS, messengers, effectors, response.

19

Q. Explain what a behavioural adaptation is. Identify 3 behavioural adaptations. Describe a behavioural adaptation an Australian animal has to assist in temperature regulation

A. The things organisms do to survive. Altering the position of the body, nocturnal activity and migration. Frill necked lizards basking in the sun.

20

Q. Explain what a structural adaptation is. Identify 3 behavioural adaptations. Describe a behavioural adaptation an Australian animal has to assist in temperature regulation

A. Structural adaptations are physical features of an organism. Insulation such as fur, feathers etc. Surface area to volume ratio. Colouration. The emu’s feathers, the wombats surface area, diamond-backed python.

21

Q. Explain what a physiological adaptation is. Identify 3 behavioural adaptations. Describe a behavioural adaptation an Australian animal has to assist in temperature regulation

A. Inner body functions of an organism. Metabolic activity. Hibernation. Blood flow (vasoconstriction and vasodilatation). Countercurrent exchange. Colouration. Wombat slowing down its metabolic rate on hot days.

22Q. Describe the differences and similarities

between a lock and key model and an induced fit model.

A. Differences: Lock and Key: Enzyme shapes are fixed or rigid and accommodate substrates of thereciprocal shape. Induced fit: Enzymes have a somewhat flexible configuration and can adapt within limits to incoming substrates. Similarities: both rely on the active site and substrate being compatible. Both allow for the existence of a co-factor which activates the enzyme.

23Q. Draw and label a negative feedback loop of

thermoregulation. Be sure to include at least 2 different response to heat and cold in your diagram.

A.

Q. List and describe 3 responses our bodies have to a hot environment.

A. Vasodilation - dilation (expansion) of the arterioles to the skin. Blood carrying heat is directed to the surface of the body so that it can be lost. (Think about how when we are hot we spread ourselves out to lose heat. Our blood vessels do the same).Sweating - Sweat is secreted through sweat pores onto the surface of the skin. Decreased metabolism - thyroid gland is stimulated causing our metabolism to slow down. This produces reduces heat produced by our bodies.

Worth – 500 points.

Q. What was the colour of the background in the first PowerPoint presentation I showed you? What is the URL of my wikispace? What is the name of this topic?

A. Yellow. www.year12biologyblasters33.wikispaces.com. Maintaining a Balance.

Worth – 100 points

Q. Who won the last rugby world cup?

A. New Zealand.

Worth - 400Q. List and describe 4 responses our bodies have to a cold

environment. A. Raised hairs on the body (goose bumps) are an attempt to trap a layer of warm air around the body. Vasoconstriction - constriction (narrowing) of the arterioles to the skin. The muscular walls of the small blood vessels known as arterioles constrict so that most blood flow is redirected to the body core. This prevents loosing heat from the cooler body surface. (Think about how when we are cold we tuck and constrict our body in to conserve heat. Our blood vessels do the same).Shivering - rapid, small muscle contractions, which generate heat in the body. Increased metabolism - thyroid gland is stimulated causing our metabolism to speed up. This produces heat.

Worth - 400Q. Watch and observe the clip.

A. Berwick St or Chatsworth Ave

Worth – 0

Worth 600Q. An experiment was conducted to determine the effects on body

function of increasing ambient temperature. Participants (100 individuals) were asked to lie down and remain as still as possible during the entire experiment. The following observations were made:

• The starting temperature of the room was 22°C. • The mean body temperature of all participants at the start of the experiment was 37.1°C. • As the room temperature increased, sweating and heart rate also increased. • As the room temperature returned to 22°C, sweating and heart rate returned to normal.

In a control group of 100 participants who were lying down in a room where

the ambient temperature was maintained at 22°C, no changes in sweating and

heart rate were observed

• Identify the dependent and independent variables in this experiment

• Identify the body system that monitors and responds to changes in external temperature.

• Draw and label a model of a feedback mechanism that explains the observations made in the experiment

A. Dependent variable - the effects on body function of increasing ambient temperature

Independent variable – temperature change.

Hypothalamus or Thermorecptors