Biology 9700 · AS & A Level
Homeostasis in mammals
80 practice questions on Homeostasis in mammals, with worked solutions and instant marking.
Fig. 5.1 shows how hormones A and B help to regulate blood glucose concentration.
Feb/March 2016
Fig. 1.1 contains nephron diagrams taken from the kidneys of three mammals, P, Q and R. Each one has been drawn to the same scale.
Feb/March 2017
Glucagon is one hormone that acts as a cell signalling molecule. Table 2.1 sets out the main events that happen when the blood glucose concentration drops below the set point. The events are not arranged in the correct sequence.
Feb/March 2019
People with sickle cell anaemia have red blood cells with a lower capacity for carrying oxygen.
Feb/March 2022
Fig. 1.1 is a sketch of a longitudinal section (LS) through a human kidney.
Feb/March 2023
Fig. 1.1 presents a diagram of a nephron.
Feb/March 2024
Fig. 6.1 presents part of the control mechanism responsible for regulating blood glucose concentration.
Feb/March 2025
Describe how a kidney nephron and its associated blood vessels are structured.
May/June 2010
About 40% of adults who have cystic fibrosis (CF) go on to develop a type of diabetes called cystic fibrosis-related diabetes (CFRD). This is believed to occur because the accumulation of thick secretions in the pancreas destroys $\beta$ cells.
May/June 2011
Section B. Answer only one question.
May/June 2012
Section B. Answer one question.
May/June 2012
Section B. Select one question to answer.
May/June 2012
The human kidneys handle $1200\,\text{cm}^3$ of blood each minute. Out of this $1200\,\text{cm}^3$, $700\,\text{cm}^3$ is plasma. When blood flows through the glomeruli in the kidneys, $125\,\text{cm}^3$ of fluid moves into the renal capsules (Bowman’s capsules). This fluid is known as the glomerular filtrate and it is formed by a process named ultrafiltration.
May/June 2013
In mammals, osmoreceptors in the hypothalamus of the brain continually monitor the water potential of the blood. If the water potential of the blood falls, ADH (antidiuretic hormone) is made by cells in the hypothalamus and then passed into the blood through an endocrine gland.
May/June 2014
Adipose tissue is a specialised connective tissue whose main role is to act as the body’s principal storage tissue in the form of triglycerides. In humans, there are two forms of adipose tissue: white adipose tissue (WAT) and brown adipose tissue (BAT). WAT is the more abundant type and is located beneath the skin and around some internal organs. BAT occurs in infants around the back and shoulders. In adults, BAT is present too, but in much smaller amounts. BAT cells contain a greater number of mitochondria than WAT cells. BAT helps to keep blood temperature constant when the outside environment is cold.
May/June 2014
A key role of control systems in mammals is maintaining homeostasis.
May/June 2016
In mammals, excess amino acids cannot be kept in the body. Outline how liver cells convert excess amino acids into urea.
May/June 2016
One important role of control systems in mammals is homeostasis. Explain what is meant by the term homeostasis.
May/June 2016
In mammals, the kidney is an organ that helps maintain homeostasis.
May/June 2017
Explain how dip sticks are used to test a urine sample for glucose.
May/June 2017
Fig. 6.1 shows a Bowman’s (renal) capsule from a nephron in a mammalian kidney. On Fig. 6.1, use label lines and letters to identify: E - the efferent arteriole G - the glomerulus P - the podocyte cell region.
May/June 2017
The mammalian kidney is one organ that helps to maintain homeostasis.
May/June 2017
Section B. Respond to one question.
May/June 2017
Section B. Answer only one question.
May/June 2018
Some people have diabetes. In type 1 diabetes, the pancreas does not make enough insulin. Fig. 7.1 shows the blood glucose concentrations of a type 1 diabetic person and a non-diabetic person at regular intervals after they drink a glucose drink. Describe the results shown in Fig. 7.1.
May/June 2019
Fig. 5.1 shows a photomicrograph of a section of kidney cortex.
May/June 2019
Fig. 5.1 shows a photograph of a kidney section.
May/June 2019
The enzyme alanine transaminase (ALT) is located in the liver. It catalyses the conversion of the amino acid $alanine$ and $\text{-ketoglutarate}$ to the amino acid glutamate.
May/June 2020
Thermoregulation refers to the maintenance of the body’s core temperature. Thermoreceptors transmit details of any change in core temperature to the hypothalamus. The hypothalamus maintains core temperature by sending impulses that trigger a range of physiological responses. Table 6.1 shows physiological responses when core temperature falls.
May/June 2021
The bottlenose dolphin, $\textit{Tursiops truncatus}$, is an aquatic mammal with adaptations for retaining heat while it swims in cold water. Fig. 6.1 presents a bottlenose dolphin.
May/June 2021
In mammals, blood glucose concentration has to be kept within tight limits so that body cells can operate efficiently.
May/June 2022
Ultrafiltration in the kidney occurs between the glomerulus and the Bowman’s capsule. The afferent blood vessel that carries blood to the glomerulus has a wider lumen than the efferent blood vessel. Explain why the lumen of the afferent blood vessel has to be wider than the lumen of the efferent blood vessel.
May/June 2022
Mammalian blood must keep its water potential within a tight range if cells are to work efficiently; this control is known as osmoregulation. Relative medullary thickness (RMT) shows how much of a kidney is made up of medullary tissue. $\text{RMT} = \dfrac{\text{thickness of medulla}}{\text{kidney size}} \times 10$. Table 1.1 gives the link between the RMT and the urine concentration formed by four mammals from different habitats.
May/June 2022
Insulin has a key part in keeping blood glucose concentration under control. An investigation tracked how blood glucose concentration and blood insulin concentration changed after a meal rich in glucose had been eaten. The results are shown in Fig. 10.1.
May/June 2022
The kidney plays a major part in homeostasis, and one of its functions is osmoregulation.
May/June 2023
Fig. 6.1 shows a photomicrograph of a section through a Bowman’s capsule and a glomerulus. On Fig. 6.1, use label lines and letters to identify: F - where the glomerular filtrate is found; P - where the blood plasma is found.
May/June 2023
The passage gives an overview of the endocrine system. Fill in the blanks using the most suitable scientific terms.
May/June 2023
Fig. 6.1 displays a section of the Bowman’s capsule in a kidney nephron. Name structures A, B and C.
May/June 2023
Osmoregulation refers to the control of the water potential in body fluids such as blood.
May/June 2024
In mammals, the concentration of blood glucose is kept near a fixed set point so that the mammal can operate efficiently. This is an example of homeostasis.
May/June 2024
Fig. 1.1 shows how antidiuretic hormone (ADH) affects the cells in the collecting duct. The cell-signalling pathway used by ADH is comparable to the one glucagon uses in liver cells.
May/June 2024
Inside the kidney, a range of molecules pass between the blood and the kidney nephron. Table 6.1 shows how molecules move at three parts of the nephron, P, Q and R.
May/June 2025
Insulin is a cell-signalling molecule in the endocrine system.
May/June 2025
The kidneys play a part in excretion and osmoregulation. Excretion is the elimination of metabolic waste products, or the removal of substances that are present in excess.
May/June 2025
Describe how a fall in the water potential of the blood results in an increase in the concentration of antidiuretic hormone (ADH) in the blood.
May/June 2025
Urea is the chief nitrogenous waste in humans. It is formed in the liver and excreted in urine by the kidneys.
Oct/Nov 2010
Asthma is a respiratory system disease.
Oct/Nov 2011
Table 7.1 summarises how several events change the blood concentrations of glucose, insulin and glucagon in a healthy person.
Oct/Nov 2011
Describe how insulin helps maintain a constant blood glucose concentration.
Oct/Nov 2013
Section B. Answer one question.
Oct/Nov 2014
Selective reabsorption is one major function of the kidney nephron. During this process, water is moved rapidly across cell surface membranes. To allow this fast movement, protein channels called aquaporins must be present. Fig. 6.1 shows a nephron.
Oct/Nov 2015
Section B - Respond to one question.
Oct/Nov 2016
Explain how glucose is reabsorbed from a nephron in the kidney back into the blood.
Oct/Nov 2016
Homeostasis in mammals depends on negative feedback mechanisms.
Oct/Nov 2017
A human body temperature is kept near its set point of about $37^{\circ}\text{C}$. When it goes above this level, physiological responses start to bring it back to the set point. Vasodilation and sweating are two such responses. Explain how vasodilation and sweating help to return the body temperature to its set point.
Oct/Nov 2017
In mammals, homeostasis depends on negative feedback mechanisms.
Oct/Nov 2017
Describe how the nephron and its linked blood vessels are structurally adapted for ultrafiltration.
Oct/Nov 2018
Describe how the nephron and its associated blood vessels are arranged to support ultrafiltration.
Oct/Nov 2018
ADH is a hormone released into a mammal’s blood when the internal environment changes.
Oct/Nov 2019
ADH is a hormone released into the blood of a mammal whenever changes occur in the internal environment.
Oct/Nov 2019
Insulin is carried in the blood throughout the body. The cells of the liver, muscle tissue and adipose (fat) tissue possess receptors for insulin.
Oct/Nov 2020
Fig. 1.1 shows a diagram of a kidney nephron together with some of its blood vessels.
Oct/Nov 2021
Ultrafiltration takes place in the Bowman’s capsule of a nephron. Fig. 1.1 shows a diagram of part of a Bowman’s capsule and glomerulus.
Oct/Nov 2021
Describe the functions of ADH and the collecting ducts in osmoregulation.
Oct/Nov 2021
Fig. 1.1 shows a diagram of a kidney nephron and some of its blood vessels.
Oct/Nov 2021
The passage that follows describes homeostasis.
Oct/Nov 2022
Fig. 8.1 shows a diagram of a kidney nephron. Using Fig. 8.1, identify A, B and C.
Oct/Nov 2022
Glucagon is involved in maintaining blood glucose concentration.
Oct/Nov 2022
Selective reabsorption occurs in the proximal convoluted tubule of a kidney nephron. Fig. 8.1 is a diagram showing two cells of the proximal convoluted tubule and part of the neighbouring blood capillary.
Oct/Nov 2022
The passage below describes homeostasis. Fill in the passage by choosing the most suitable scientific terms.
Oct/Nov 2022
Fig. 8.1 shows a diagram of a kidney nephron. Using Fig. 8.1, name A, B and C.
Oct/Nov 2022
As blood glucose concentration drops, the pancreas releases glucagon into the blood, where it is carried to the cells. Fig. 6.1 shows how glucagon affects liver cells.
Oct/Nov 2023
The mammalian kidney carries out urea excretion and osmoregulation, which is the homeostatic regulation of the blood’s water potential.
Oct/Nov 2024
Fig. 1.1 shows part of a Bowman’s capsule together with a glomerular capillary.
Oct/Nov 2024
Blood glucose concentration is kept near a set point by homeostasis. Explain the principles of homeostasis.
Oct/Nov 2024
In mammals, the kidney carries out: • the removal of urea by excretion • osmoregulation (the homeostatic regulation of the blood’s water potential).
Oct/Nov 2024
Fig. 9.1 presents a longitudinal section through a human kidney. Name the regions of the kidney labelled X and Y in Fig. 9.1.
Oct/Nov 2025
Phosphoinositide 3-kinase (PI3K) and protein kinase B(PKB) are enzymes that help control blood glucose concentration. Fig. 6.1 illustrates a cell-signalling pathway in a muscle cell involving insulin, PI3K and PKB.
Oct/Nov 2025
Fig. 9.1 shows a lengthwise section through a human kidney.
Oct/Nov 2025
Some individuals may develop a disorder named type 2 diabetes. In people with type 2 diabetes, glucose uptake from the blood is reduced. In certain cases, the pancreas is unable to produce enough insulin to maintain blood glucose concentration within a healthy range. One person with type 2 diabetes and one person without type 2 diabetes were each given a glucose drink. Blood glucose concentration for both people was recorded at regular intervals over 120 minutes. The outcomes are displayed in Fig. 6.1.
Oct/Nov 2025