Lunularia cruciata is a primitive plant. Its body consists of a flattened sheet of photosynthetic tissue called a thallus. Fig. 5.1 shows L. cruciata with two different types of reproductive structure, labelled A and B, on its surface. [Figure 5.1]

1. (a)Structures A and B and the thallus of L. cruciata are haploid. Explain what is meant by haploid.[2]
2. (b)Structure A contains pale discs of tissue, C, that can germinate into new L. cruciata. The new plants that develop from C are genetically identical to the parent plant in Fig. 5.1. Structure B contains male sperm that are chemically attracted to swim to female eggs on a neighbouring parent plant. When the egg and sperm fuse, they form structure D. Structure D develops to produce spores that grow into new plants that are genetically different from the two parent plants. Identify which of the structures A, B, C and D are: associated with sexual reproduction produced by mitosis the site of meiosis Each letter may be used once, more than once, or not at all.[3]
3. (c)Fig. 5.2 shows a horse, Equus caballus. Horses are diploid animals that reproduce sexually. Male and female horses produce gametes, which fuse to form genetically different offspring. [Figure 5.2] Explain the need for a reduction division during meiosis in the production of gametes in animals such as horses.[3]

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