Biology Form 3

Yaliyomo

1. 1. Classification of Living Things: Kingdom Plantae

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   • Kingdom Plantae and division Bryophyta
   • Division Filicinophyta: ferns
   • Seed plants: conifers and flowering plants
   • Monocots and dicots, evolutionary trend and importance of plants
   • Summary

   General features of kingdom Plantae Plants are multicellular eukaryotes with cellulose cell walls and chlorophyll in chloroplasts, so they are autotrophic . They store food as starch and show alternation of generations : a gametophyte generation (produces gametes) alternates with a sporophyte generation (produces…

2. 2. Excretion

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   • Meaning of excretion and excretory products
   • The urinary system and the kidney
   • The nephron and urine formation
   • Kidney disorders, dialysis and excretion in plants
   • Summary

   Meaning of excretion Excretion is the removal of waste products of metabolism and substances in excess from the body. It is different from egestion , which is removal of undigested food (faeces) that never entered body cells. If wastes such as urea accumulate, they become poisonous and upset the internal environment.…

3. 3. Regulation (Homeostasis)

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   • Meaning of homeostasis and negative feedback
   • Regulation of body temperature
   • Regulation of blood glucose
   • Osmoregulation and the liver
   • Summary

   Meaning of homeostasis Homeostasis is the maintenance of a constant internal environment (the tissue fluid around cells) despite changes outside or inside the body. Factors kept constant include body temperature, blood glucose level, water and salt balance, pH and carbon dioxide level. Cells work best when conditions…

4. 4. Coordination 1: Coordination in Plants and Chemical Coordination in Animals

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   • Coordination and responses in plants
   • Plant hormones and their uses
   • Experiments on tropisms
   • The endocrine system
   • Hormone disorders; nervous and hormonal coordination compared
   • Summary

   Meaning of coordination Coordination is the way different parts of an organism work together in an organised way in response to changes. A change that causes a response is a stimulus (e.g. light, gravity, touch, temperature, chemicals). The ability to detect and respond to stimuli is called sensitivity or irritability…

5. 5. Coordination 2: The Nervous System and Sense Organs

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   • The nervous system and neurones
   • Reflex actions and the reflex arc
   • The brain and the effects of drugs
   • The eye
   • The ear, hearing and balance
   • Summary

   The nervous system The human nervous system has two parts: the central nervous system (CNS) – brain and spinal cord – and the peripheral nervous system – nerves linking the CNS to all body parts. Messages travel as electrical nerve impulses along nerve cells called neurones . Neurones Sensory neurone – carries impulses…

6. 6. Movement

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   • Movement, locomotion and types of skeleton
   • The human skeleton
   • Joints
   • Muscles and antagonistic pairs
   • Locomotion in fish
   • Summary

   Meaning of movement and locomotion Movement is a change in position of a part or the whole of an organism. Locomotion is movement of the whole organism from one place to another. Animals move to find food, water and mates, escape predators and harsh conditions, and find new habitats. Plants do not usually move from…

7. 7. Reproduction 1: Reproduction in Plants

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   • Types of reproduction and asexual reproduction
   • Vegetative propagation
   • Structure of a flower
   • Pollination
   • Fertilisation, seeds and fruits
   • Dispersal of fruits and seeds
   • Summary

   Meaning and types of reproduction Reproduction is the process by which organisms produce new individuals of their own kind, so the species continues. Asexual reproduction involves one parent and no gametes; offspring are genetically identical ( clones ). Sexual reproduction involves the fusion of male and female…

8. 8. Reproduction 2: Reproduction in Humans

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   • The male reproductive system
   • The female reproductive system and gametes
   • Puberty and the menstrual cycle
   • Fertilisation, pregnancy and birth
   • Care in pregnancy, breastfeeding and family planning
   • Summary

   The male reproductive system The testes produce sperm and the hormone testosterone . They lie in the scrotum , outside the body, because sperm develop best at a temperature slightly below 37 °C. Sperm are stored in the epididymis , pass along the sperm duct (vas deferens) and mix with fluids from the seminal vesicles ,…