Theory

CH16 - INHERITED CHANGE

Populations of the moth *Biston betularia* live in Europe and in North America. The most common phenotype on both continents is a pale wing colour wit...

2024 Winter

3

Theory

CH16 - INHERITED CHANGE

The scientist Gregor Mendel investigated differences in the length of the stem in the pea plant, Pisum sativum. In 1866, he published the results of h...

2024 Spring

2

Theory

CH16 - INHERITED CHANGE

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

CH16 - INHERITED CHANGE

The tortoise beetle, Chelymorpha alternans, is an insect found in Panama that has several different colour patterns. Fig. 3.1 shows a tortoise beetle....

2024 Summer

2

Theory

CH16 - INHERITED CHANGE

Cystic fibrosis is an autosomal recessive genetic disease. People with cystic fibrosis have a homozygous recessive genotype. (a) Explain the meaning ...

2024 Spring

2

Theory

CH16 - INHERITED CHANGE

(a) Structures A and B and the thallus of L. cruciata are haploid.Explain what is meant by haploid.......................................................

2024 Winter

3

Theory

CH16 - INHERITED CHANGE

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

CH16 - INHERITED CHANGE

Holstein Friesian cattle are a breed of cattle used by dairy farmers in many countries of the world for the high milk yield of their cows.Fig. 4.1 sho...

2024 Spring

4

Theory

CH16 - INHERITED CHANGE

Genetic crosses can be used to investigate patterns of inheritance.(a) A mutation in a gene involved in fruit colour in tomato plants, _Solanum lycope...

2024 Winter

3

Theory

CH16 - INHERITED CHANGE

(a) Fig. 6.1 is a diagram of part of a mitochondrion.On Fig. 6.1, use arrows to show the route taken by oxygen from the cytoplasm into the mitochondri...

2024 Summer

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

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