B I OLOG Y
Variation for Survival Ideas you have met before
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Variation and classification Living things are classified into broad groups according to observable characteristics, similarities and differences.
Adaptations Animals and plants are adapted to the conditions of the habitats in which they live. An adaptation is a way an animal’s body helps it survive in its environment – for example meerkats have dark circles around their eyes, which act like sunglasses, helping them see even when the Sun is shining very brightly.
Cells Cells are the building blocks of life. They contain structures called organelles, which all have specific jobs. Every cell, except red blood cells, contains a nucleus. The nucleus contains DNA, which controls the reactions inside the cell and is involved in making the cell reproduce.
Reproduction The gametes in animals are the egg cell and the sperm cell. The gametes in plants are the pollen cell and the ovule. Fertilisation happens when the nucleus of a male gamete fuses with the nucleus of a female gamete.
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KS3 Science Book 3: Variation for Survival
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