Theory

CH17 - SELECTION AND EVOLUTION

(a) Explain how changes in the nucleotide sequence of DNA may affect the amino acid sequence in a protein.[7](b) Explain how natural selection may bri...

2009 Summer

Theory

CH17 - SELECTION AND EVOLUTION

(a) *Asellus aquaticus* is a small freshwater crustacean. 200 *A. aquaticus* were released into a pond where there had previously been none. The pond...

2009 Winter

Theory

CH17 - SELECTION AND EVOLUTION

(a) Complete Fig. 4.1 by writing letters to represent the sets of chromosomes in bread wheat.(b) Explain why hybridisation between emmer wheat and goa...

2009 Winter

Theory

CH17 - SELECTION AND EVOLUTION

(a) A recent study of the house mouse, Mus musculus, on the island of Madeira resulted in the following observations. • There are six distinct popul...

2009 Winter

Theory

CH17 - SELECTION AND EVOLUTION

(a) Explain how two parents, both of whom produce normal amounts of AG, can produce a child with Pompe disease...........................................

2009 Winter

Theory

CH17 - SELECTION AND EVOLUTION

Anole lizards are found throughout the Caribbean and the surrounding mainland. There are many species. Each species is found only on one island or a s...

2010 Summer

Theory

CH17 - SELECTION AND EVOLUTION

The American crocodile, Crocodylus acutus, was classified as an endangered species by the USA in 1975. It is found in estuarine regions of southern Fl...

2010 Summer

Theory

CH17 - SELECTION AND EVOLUTION

The fruitfly, _Drosophila_, has many different species. Three of these species, _Drosophila pseudoobscura_, _D. persimilis_ and _D. miranda_, are thou...

2010 Summer

Theory

CH17 - SELECTION AND EVOLUTION

The American crocodile, Crocodylus acutus, was classified as an endangered species by the USA in 1975. It is found in estuarine regions of southern Fl...

2010 Summer

Theory

CH17 - SELECTION AND EVOLUTION

The fruitfly, \textit{Drosophila}, has many different species. Three of these species, \textit{Drosophila pseudoobscura}, \textit{D. persimilis} and \...

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