Theory

CH13 - PHOTOSYNTHESIS

(a) A touch stimulus to an $M. pudica$ leaf causes an action potential to be generated. The action potential results in changes in cells, which cause ...

2024 Winter

3

Theory

CH13 - PHOTOSYNTHESIS

Stomata in leaves respond to changes in environmental conditions by opening and closing. This regulates carbon dioxide uptake and water loss.(a) Descr...

2024 Summer

3

Theory

CH13 - PHOTOSYNTHESIS

Photosynthesis is the energy transfer process that occurs in chloroplasts.Fig. 5.1 shows some biochemical events that occur in a chloroplast during th...

2024 Summer

3

Theory

CH13 - PHOTOSYNTHESIS

(a) Paper chromatography is a technique that can be used to separate and identify different chloroplast pigments.Describe how the results of paper chr...

2024 Winter

4

Theory

CH13 - PHOTOSYNTHESIS

(a) In plants, stomata open and close in response to changes in environmental conditions. Explain why stomata need to open and close according to envi...

2024 Summer

3

Theory

CH13 - PHOTOSYNTHESIS

(a) Experiments were carried out to determine the effect of light intensity on the rate of photosynthesis of a species of the unicellular prototist, C...

2024 Summer

1

Theory

CH13 - PHOTOSYNTHESIS

(a) A touch stimulus to an $M. \; pudica$ leaf causes an action potential to be generated.The action potential results in changes in cells, which caus...

2024 Winter

1

Theory

CH13 - PHOTOSYNTHESIS

(a) Table 1.1 describes some functions that occur in different parts of a chloroplast.Complete Table 1.1 by identifying the letter on Fig. 1.1 that is...

2023 Summer

3

Theory

CH13 - PHOTOSYNTHESIS

Oryza is a genus of grass plants that includes the rice, Oryza sativa, a food crop.(a) Farmers flood fields of rice because this encourages faster gro...

2023 Summer

3

Theory

CH13 - PHOTOSYNTHESIS

Chloroplasts carry out photosynthesis. Fig. 1.1 shows some structural features of a chloroplast and some processes that occur within it. (a) (i) I...

2023 Winter

3

Theory

CH9 - GAS EXCHANGE AND SMOKING

(a) Fig. 1.1 is an image of a transverse section through the trachea of the gas exchange system.Write the names of structures X and Y on Fig. 1.1 in t...

2021 Spring

3

Theory

CH2 - BIOLOGICAL MOLECULES

Starch molecules are the main storage molecules in many types of cereal grain, such as the grainof the barley plant.(a) When the seed inside a barley ...

2021 Spring

3

Theory

CH11 - IMMUNITY

T-helper lymphocytes and Leydig cells are two types of mammalian cells. The main role of T-helper lymphocytes and Leydig cells is to synthesise and se...

2021 Spring

3

Theory

CH8 - TRANSPORT IN MAMMALS

(a) Using a light microscope at a magnification of ×400, it is possible to identify different types of blood cell in prepared slides of mammalian blo...

2021 Spring

3

Theory

CH5 - THE MITOTIC CELL CYCLE

Each meristem cell in a leaf bud is able to grow and divide by mitosis to produce two daughter cells that are genetically identical to each other and ...

2021 Spring

3

Theory

CH10 - INFECTIOUS DISEASE

In March 2019, a tropical cyclone in the south-west Indian Ocean caused widespread flooding in a number of countries.The flooding and the damage cause...

2021 Spring

3

Theory

CH17 - SELECTION AND EVOLUTION

(a) The European eel, Anguilla anguilla, is a fish. The sizes of eel populations tend to remain relatively stable despite eels producing large numbers...

2021 Spring

3

Theory

CH18 - BIODIVERSITY, CLASSIFICATION AND CONSERVATION

(a) The grey wolf, *Canis lupus*, is a large predator. During the 20th century, the grey wolf in south-west Europe was hunted almost to extinction.Fig...

2021 Spring

3

Theory

CH19 - GENETIC TECHNOLOGY

Vitamin A deficiency is a widespread public health problem.One source of vitamin A is carotene in the diet. Carotene can be converted to vitamin A in ...

2021 Spring

2

Theory

CH13 - PHOTOSYNTHESIS

Red algae are multicellular photosynthetic prototists that contain phycoerythrin. Phycoerythrin is a photosynthetic pigment.(a) Fig. 4.1 shows:• the...

2021 Spring

3