Theory

CH14 - HOMEOSTASIS

(a) In mammals, blood glucose concentration is maintained around a set point so that the mammal can function efficiently. This is an example of homeos...

2024 Summer

6

Theory

CH14 - HOMEOSTASIS

(a) Blood glucose concentration is maintained around a set point by homeostasis. Explain the principles of homeostasis.[4]  (b) Glycogen phospho...

2024 Winter

4

Theory

CH14 - HOMEOSTASIS

(a) Fig. 1.1 is a diagram of part of a Bowman's capsule and a glomerular capillary. (i) Identify structures A and B. (ii) The glomerular filtrate ...

2024 Winter

5

Theory

CH14 - HOMEOSTASIS

(a) Fig. 1.1 is a diagram of a nephron. Label Fig. 1.1 using: • one labelling line and the letter A to identify a region that contains urine ...

2024 Spring

4

Theory

CH14 - HOMEOSTASIS

Osmoregulation is the control of the water potential of body fluids such as blood. (a) Osmoreceptors and antidiuretic hormone (ADH) have an important...

2024 Summer

4

Theory

CH14 - HOMEOSTASIS

The mammalian kidney is responsible for: • the excretion of urea • osmoregulation (the homeostatic control of the water potential of the b...

2024 Winter

8

Theory

CH14 - HOMEOSTASIS

The kidney is an important organ of homeostasis. One role of the kidney is osmoregulation.  (a) Fig. 5.1 is a photomicrograph of part of a kidne...

2023 Summer

8

Theory

CH14 - HOMEOSTASIS

(a) Fig. 1.1 is a drawing of a longitudinal section (LS) of a human kidney. Use the letters A, B, C and D in Fig. 1.1 to complete Table 1.1. Each ...

2023 Spring

3

Theory

CH14 - HOMEOSTASIS

Amino acids are the monomers that are used to produce proteins in organisms. Amino acids also have other, non-protein, roles in the body. (a) Fig. 7....

2023 Summer

5

Theory

CH14 - HOMEOSTASIS

(a) (i) When blood glucose concentration decreases, glucagon is released by the pancreas into the blood and is transported to the cells.  Fig. 6...

2023 Winter

2

Theory

CH7 - TRANSPORT IN PLANTS

(a) The structure of a phloem sieve tube element is adapted to its function.Each of explanations A to F describes how a particular structural feature ...

2020 Spring

3

Theory

CH3 - ENZYMES

Phosphatidate phosphatase (PAP) enzymes have an important role in lipid metabolism.The reaction catalysed by PAP is shown in Fig. 2.1.Experiments were...

2020 Spring

4

Theory

CH8 - TRANSPORT IN MAMMALS

During one cardiac cycle:blood enters the heart from the lungs and from the rest of the bodyblood leaves the heart to be transported to the lungs and ...

2020 Spring

4

Theory

CH9 - GAS EXCHANGE AND SMOKING

(a) When a section of lung tissue is viewed using a light microscope, it is possible to identify the trachea, the bronchus, the bronchioles and the al...

2020 Spring

3

Theory

CH11 - IMMUNITY

Myasthenia gravis and HIV/AIDS both involve disorders of the immune system.(a) Outline why myasthenia gravis is described as a disorder of the immune ...

2020 Spring

3

Theory

CH1 - CELL STRUCTURE

Fig. 6.1 is a transmission electron micrograph of a plant parenchyma cell.(a) The external environment of the parenchyma cell has a higher water poten...

2020 Spring

4

Theory

CH14 - HOMEOSTASIS

(a) Fig. 1.1 represents part of the wall of a proximal convoluted tubule (pct) in a kidney nephron. (i) Name the features of the wall of a pct that...

2020 Spring

4

Theory

CH11 - IMMUNITY

Severe combined immunodeficiency (SCID) is a group of life-threatening diseases. SCID is caused by mutations that prevent the normal function of the i...

2020 Spring

4

Theory

CH16 - INHERITED CHANGE

Flowers of the common morning-glory plant, Ipomoea purpurea, can have several different phenotypes. An example of these flowers is shown in Fig. 3.1.[...

2020 Spring

3

Theory

CH16 - INHERITED CHANGE

The rainbow trout, Oncorhynchus mykiss, is a fish that is bred in commercial fish farms. Rainbow trout that have a blue-silver colour are sold at a hi...

2020 Spring

3