Homeostasis practice test Multi-choice 1 a b c d Which of the following is the correct order: stimulus response coordinating centre receptor effector stimulus receptor coordinating centre response effector receptor stimulus coordinating centre response effector stimulus receptor coordinating centre effector response 2 a b c d If a response reduces a stimulus this is an example of negative feedback positive feedback homeostasis temperature control 3 a b c d Animal cells placed in a strong salt solution are likely to shrivel through loss of water become turgid and burst remove salt by endocytosis absorb water through osmosis 4 Which of the following lists contains a physiological adaptation principally associated with reducing heat loss? small ears and short legs long, thick hair covering the body an increase in metabolic rate reduced blood flow to the skin a b c d 5 a b c d An ectothermic animal may be able to maintain its internal body temperature within reasonable limits by vasoconstriction and vasodilation of blood vessels close to its skin surface raising and lowering its hair follicles reducing or increasing its rate of metabolism moving in or out of a warmer part of its environment 6 a b c d A structural feature that some reptiles have to help absorb energy from the sun is a long slender body a dark colour on the upper side of the body long legs to raise the animal above the surface of the ground reduced appendages such as ears and nose sizes 7 a b c d On a hot, dry day a mammal would lose water in all but one of the following ways: through evaporation from its lungs in its faeces and urine through evaporation from its skin through respiration 8 The diagram shows the transverse section through two plant structures. Which label shows the plant tissue that transports water and minerals in the plant? a 1 b 2 c 3 d 4 9 a b c d A terrestrial plant may control its water loss by reducing its rate of photosynthesis absorbing water through its root hair cells changing the aperture of its stomata reducing its stomatal guard cells 10 Halophytes are able to tolerate high salt levels in the soil whereas other plants cannot. This is generally because non-halophytes tend to take up the salt which is toxic to them whereas all halophytes exclude the salt cannot absorb water from saline soil whereas halophytes can absorb water dehydrate because more water leaves the plant than enters by osmosis whereas halophytes have mechanisms to absorb more water than they lost to the soil have roots which grow just under the surface of the soil which is usually more heavily contaminated with salt a b c d 11 a b c d Which of the following temperature regulation systems does not assist cooling in plants? Leaves with a large surface area positioning of stomata towards the ground evaporation of water from plants closing of stomata in the hottest part of the day The four statements below relate to questions 12-15. Read each statement carefully before answering the questions. A B C D 12 a b c d Burrowing into the soil and seeking refuge there during the hottest months of the year. The capacity to produce extremely concentrated urine while maintaining a normal amount of water in the body fluids. A small surface area to volume ratio as a result of small appendages, small ears and a larger than normal body size. A special organelle in a single-celled animal which collects water from the animal’s cytoplasm and periodically contracts to expel the water into the surroundings. Which statement refers to a behavioural adaptation? A B C D 13 a b c d Which statement refers to an adaptation/s possessed by an animal which probably lives in a cold environment? A B C D 14 a b c d Which physiological adaptation is likely to be possessed by a small desert dwelling animal? A B C D 15 a b c d The adaptation which allows an organism to live in a freshwater lake is? A B C D Short answer 16 When the hypothalamus of a mammal detects a rise in the body’s blood temperature, it sends out nerve impulses which cause the vasodilation of blood vessels close to the skin. This vasodilation results in more blood flowing close to the surface of the skin and consequently a greater loss of heat from the body by radiation and conduction to the atmosphere. a In the above discussion, what is the: i receptor? ____________________________________ (1 mark) ii effector? _____________________________________ (1 mark) iii stimulus? _____________________________________ (1 mark) iv response? _____________________________________ (1 mark) b Why is this called a negative feedback system? (1 mark) _____________________________________________________________________________________ _____________________________________________________________________________________ c In this example, where is the co-ordinating centre and what does it do? (2 marks) _____________________________________________________________________________________ _____________________________________________________________________________________ d Draw the stimulus response model. (2 marks) 17 Endotherms are animals that maintain a constant body temperature independent of the environment. a Explain why an animal such as a mouse has a higher metabolic rate than a donkey when both animals live in a cool temperate environment. (4 marks) _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ b Marsupials such as wombats which live on the Australian mainland are smaller in general than their counter-parts that live in Tasmania. What advantage would their greater size give to the Tasmanian wombats? (2 marks) _____________________________________________________________________________________ _____________________________________________________________________________________ c The hypothalamus detects changes in the internal temperature of endotherms. Discuss two responses which occur in endotherms when the hypothalamus detects a: i rise in body temperature. (2 marks) _____________________________________________________________________________________ _____________________________________________________________________________________ ii fall in body temperature. (2 marks) _____________________________________________________________________________________ _____________________________________________________________________________________ d The following diagram shows how the temperature varies along the length of an artery and a nearby vein which carry blood to and from the foot of an Antarctic bird which is standing on ice. i What is the exchange of heat between the artery and vein called? (1 mark) _____________________________________________________________________________________ ii Of what advantage to the bird is there in having the artery and the vein so close to one another in the leg? (2 marks) _____________________________________________________________________________________ _____________________________________________________________________________________ iii What category of adaptation is this an example of? (1 mark) _____________________________________________________________________________________ 18 a Describe and explain one adaptation that a terrestrial plant may have to: reduce heat absorption in a hot dry environment. (2 marks) _____________________________________________________________________________________ _____________________________________________________________________________________ b reduce water loss on a hot, dry day. (2 marks) _____________________________________________________________________________________ _____________________________________________________________________________________ c increase water absorption in a hot, dry environment. (2 marks) _____________________________________________________________________________________ _____________________________________________________________________________________ d remove salt from its cells in high saline soil conditions. (2 marks) _____________________________________________________________________________________ _____________________________________________________________________________________ e remove salt filled leaves in high saline soil conditions. (2 marks) _____________________________________________________________________________________ _____________________________________________________________________________________ 19 To compare the three nitrogenous wastes, complete the table below. Nitrogenous waste Ammonia Advantages Disadvantages (9 marks) Animal examples Urea Uric acid Extended response What is meant by ‘homeostasis’ in living organisms? Explain how an organism’s survival depends of its ability to respond to changes in its external and internal environments. Use the negative feedback model to illustrate your answer.