Theory

CH9 - GAS EXCHANGE AND SMOKING

(a) Fig. 6.1 is an electron micrograph of a cancer cell in the process of dividing by mitosis. The stage of mitosis visible in Fig. 6.1 is metaphase.S...

2009 Summer

MCQ

CH9 - GAS EXCHANGE AND SMOKING

What would be seen in an electron micrograph of a bronchus wall?1 cartilage cells2 ciliated cells3 exocytotic vesicles

2009 Winter

MCQ

CH9 - GAS EXCHANGE AND SMOKING

An oxygen molecule diffuses directly from the air in an alveolus to haemoglobin in a red blood cell. What is the minimum number of cell surface membr...

2009 Winter

MCQ

CH9 - GAS EXCHANGE AND SMOKING

A disease damages alveoli. Which effect does this have on the gas exchange surface area and volume of the lungs? [Table_1]

2009 Winter

MCQ

CH9 - GAS EXCHANGE AND SMOKING

A disease damages alveoli.Which effect does this have on the gas exchange surface area and volume of the lungs?[Table_1]

2009 Winter

MCQ

CH9 - GAS EXCHANGE AND SMOKING

An oxygen molecule diffuses directly from the air in an alveolus to haemoglobin in a red blood cell. What is the minimum number of cell surface membr...

2009 Winter

MCQ

CH9 - GAS EXCHANGE AND SMOKING

What would be seen in an electron micrograph of a bronchus wall?1. cartilage cells2. ciliated cells3. exocytotic vesicles

2009 Winter

MCQ

CH9 - GAS EXCHANGE AND SMOKING

Below are correct statements comparing blood, tissue fluid and lymph in a capillary bed.• W lacks large plasma proteins and red blood cells and has ...

2009 Winter

Theory

CH9 - GAS EXCHANGE AND SMOKING

Fig. 3.1 is an electron micrograph of a lymphocyte in the process of cell division during an immune response.(a) With reference to Fig. 3.1,(i) name t...

2009 Winter

Theory

CH9 - GAS EXCHANGE AND SMOKING

(a) Calculate the actual diameter of the alveolus along the line X–Y.Show your working and give your answer to the nearest micrometre.Answer = ........

2010 Summer

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

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

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

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

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

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

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

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

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

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