Theory

CH17 - SELECTION AND EVOLUTION

Several different processes can affect allele frequencies in populations.(a) Outline the processes that may affect allele frequencies in wildlife popu...

2024 Winter

3

Theory

CH17 - SELECTION AND EVOLUTION

Variation exists in populations of a species and this may provide the opportunity for evolution to occur.(a) Phenotypic variation exists in many forms...

2024 Summer

3

Theory

CH17 - SELECTION AND EVOLUTION

Genes have a role in determining the overall phenotype of an organism.(a) Using haemophilia as an example, explain the relationship between a gene, a ...

2024 Summer

2

Theory

CH17 - SELECTION AND EVOLUTION

(a) Variation in a particular characteristic can be described as either discontinuous or continuous. Table 5.1 contains a list of statements that app...

2024 Winter

3

Theory

CH17 - SELECTION AND EVOLUTION

Complete the following paragraphs using the most appropriate word or words.The theory of evolution describes a process that can lead to the formation ...

2024 Spring

3

Theory

CH17 - SELECTION AND EVOLUTION

(a) Young spadefoot toads are called tadpoles and live in water in ponds.S. multiplicata tadpoles show three different phenotypes due to genetic varia...

2024 Winter

3

Theory

CH17 - SELECTION AND EVOLUTION

It has been hypothesised that the mutation rate of an animal species may affect how fast animals of that species age and how long they live (lifespan)...

2024 Summer

3

Theory

CH17 - SELECTION AND EVOLUTION

The harlequin ladybird, Harmonia axyridis, is an insect that shows discontinuous variation in colour pattern and continuous variation in body size.(a)...

2024 Summer

3

Theory

CH17 - SELECTION AND EVOLUTION

(a) Young spadefoot toads are called tadpoles and live in water in ponds.S. multiplicata tadpoles show three different phenotypes due to genetic varia...

2024 Winter

2

Theory

CH17 - SELECTION AND EVOLUTION

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

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

3

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

2

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

3

Theory

CH14 - HOMEOSTASIS

(a) Fig. 1.1 represents part of the wall of a proximal convoluted tubule (pct) in a kidney nephron.[Image_1: Fig. 1.1](i) Name the features of the wal...

2020 Spring

1

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

2

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

2

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

1