2. BIOLOGY IN CONTEXT Biology is a science for the study of living things or organisms. It also includes the study of MAN. What is biology ?

3. There are numerous branches of biology: Anatomy, Study of the bodily structure of an animal or plant.

4. There are numerous branches of biology: Anatomy, Bacteriology, The study of bacteria.

5. There are numerous branches of biology: Anatomy, Bacteriology, Biochemistry, Study of the chemistry of living organisms.

6. There are numerous branches of biology: Anatomy, Bacteriology, Biochemistry, *Botany, The study of plants. Cytology, The study of cells. *Ecology, The study of the inter-relationship between living organisms and their environment.

7. There are numerous branches of biology: Anatomy, Bacteriology, Biochemistry, *Botany, Cytology, *Ecology, Embryology, The study of embryos. Entomology, The study of insects. *Genetics, The study of how characteristics are passed from generation to generation. Histology, The study of tissues. Immunology, The study of body defence systems.

8. There are numerous branches of biology: Anatomy, Bacteriology, Biochemistry, *Botany, Cytology, *Ecology, Embryology, Entomology, *Genetics, Histology, Immunology, Microbiology, The study of microorganisms.

9. There are numerous branches of biology: Anatomy, Bacteriology, Biochemistry, *Botany, Cytology, *Ecology, Embryology, Entomology, *Genetics, Histology, Immunology, Microbiology, Morphology, The study of the external features of living organisms.

10. There are numerous branches of biology: Anatomy, Bacteriology, Biochemistry, *Botany, Cytology, *Ecology, Embryology, Entomology, *Genetics, Histology, Immunology, Microbiology, Morphology, Pathology, The study of pathogens (disease-causing agents).

11. There are numerous branches of biology: Anatomy, Bacteriology, Biochemistry, *Botany, Cytology, *Ecology, Embryology, Entomology, *Genetics, Histology, Immunology, Microbiology, Morphology, Pathology, *Physiology, The study of the normal functions of organisms.

12. There are numerous branches of biology: Anatomy, Bacteriology, Biochemistry, *Botany, Cytology, *Ecology, Embryology, Entomology, *Genetics, Histology, Immunology, Microbiology, Morphology, Pathology, *Physiology, Taxonomy, The study of classification.

13. There are numerous branches of biology: Anatomy, Bacteriology, Biochemistry, *Botany, Cytology, *Ecology, Embryology, Entomology, *Genetics, Histology, Immunology, Microbiology, Morphology, Pathology, *Physiology, Taxonomy, *Zoology, The study of animals.

14. There are numerous branches of biology: Anatomy, Bacteriology, Biochemistry, *Botany, Cytology, *Ecology, Embryology, Entomology, *Genetics, Histology, Immunology, Microbiology, Morphology, Pathology, *Physiology, Taxonomy, *Zoology, Molecular Biology, The study of chemical molecules in cells, e.g. DNA

15. There are numerous branches of biology: Anatomy, Bacteriology, Biochemistry, *Botany, Cytology, *Ecology, Embryology, Entomology, *Genetics, Histology, Immunology, Microbiology, Morphology, Pathology, *Physiology, Taxonomy, *Zoology, Molecular Biology, Palaeontology. The study of fossils.

16.  New branches of biology: Biotechnology is the application of scientific and engineering principles to the production of materials by biological agents. Genetic engineering is the technology which allow genes to be manipulated, altered and transferred from organism to organism.

17. THE DEFINITION OF LIFE - It distinguishes living things from non-living things

18. THE DEFINITION OF LIFE - It distinguishes living things from non-living things 1. Feeding or Nutrition - take in food to provide energy for living & growth - Plants: use chlorophyll to make food by photosynthesis (autotrophic nutrition) Animals: obtain food from other organisms (heterotrophic nutrition)

19. 2. Respiration It is necessary for living. It occurs in every living plant and animal cells. Energy is released from food by oxidation: glucose + oxygen  carbon dioxide + water to take in oxygen & give out carbon dioxide, e.g. humans use lungs; fish use gills + energy Breathing:

20. Plants do not have excretory organs. Wastes are turned into harmless substances & stored within the body; OR by leaf fall. 3. Excretion Metabolism are chemical processes taking place inside cells. Some by-products of metabolism are useless & harmful if accumulate. Excretion is the removal of such waste substances, e.g. carbon dioxide is removed by lungs; urea is removed by kidneys

21. Growth needs food to provide energy. 4. Growth Every organism gets bigger & more complex as it gets older. Cells grow from within by forming new living matter called cytoplasm.

22. 5. Reproduction Living organisms eventually die. The ability to continue the living of their own species is called reproduction. Sexual reproduction: Male gamete (sperm) + female gamete (ovum) X (zygote)Y (embryo) 1 cell/organism  2 cells/organisms Asexual reproduction:

23. 6. Irritability (or Sensitivity) is the ability to detect changes in both the internal & external environment, e.g. skin becomes red when hot to increase heat loss, plants can also detect external changes (stimuli) but react more slowly.

24. 7. Movement Animals move from place to place to search for food, escape their enemies. Plants move or grow towards light for photosynthesis. They anchor more deeply into soil by roots - growth movements

25. Levels of Organization Atoms  molecules  Cells  Colonies  Tissues  Organs  Systems  Organisms  Population In school cert level: cells, tissues, organs, systems, organism.

26. 1.1 ATOMIC ORGANIZATION Atoms are the smallest unit of a chemical element exist independently. Atoms do not have any overall charge. An atom consists of: protons, electrons and neutrons

28. 1.1.1 Ions If an atom loses or gains electrons it becomes an ion. Oxidation: an atom loses an electron; Reduction: an atom gains an electron.

29. 1.1.2 Isotopes Isotopes are elements have the same chemical properties as the normal element but have a different mass.

32. 1.1.2 Isotopes Isotopes are elements have the same chemical properties as the normal element but have a different mass. Isotopes can be traced by various means, even when incorporated in living matter. This makes them exceedingly useful in tracing the route of certain elements in a variety of biological processes.

34. 1.2 MOLECULAR ORGANIZATION A H 2 molecule is more stable than a single H atom by sharing electrons and forming covalent bonding. Single bond: two atoms sharing a single electron, e.g H 2 (H-H) Double bond: two atoms sharing two electrons, e.g. CO 2 (O=C=O)

39. 1.2.1 Ionic bonding Oppositely charged atoms attract one another forming ionic bonds, e.g. NaCl 1.2.2 Hydrogen bonds A weak electrostatic ( +  - ) bond is formed between two similar polarized molecules, e.g. water molecules.

41. 1.3 CELLULAR ORGANIZATION Cell: Hooke (1665) used a compound microscope to discover 'cells’. Cell Theory (Schleiden & Schwann, 1838): cells are the fundamental unit of structure and function in living organisms. Cytology: the study of cell ultrastructure by the electron microscope.

42. Colonial organization

43. 1.4 COLONIAL ORGANIZATION Colonies occurred when individual unicells failed to separated after cell division. Advantage: larger size deters predators thus increases survival. Differentiation: individual cells within a colony become different from one another in both structure and function.

44. Specialization: further differentiation result in cells performing a single function, thus cells are more dependent on one another. Cells within the colony must be highly organized and integrated. When cells are no longer capable of surviving independently, they form a multicellular organism.

45. Tissue organization

46. 1.5 TISSUE ORGANIZATION Similar cells performing the same function are grouped together into a tissue. Histology: the study of tissues

47. 1.6 ORGAN LEVEL OF ORGANIZATION An organ (e.g. stomach) is a structural & functional unit of a living organism. It comprises of tissues which are co-ordinated to perform a variety of functions. Organs grouped together to form organ systems, e.g. digestive system.

48. The leaf: an organ for photosynthesis Heart: an organ for pumping blood

49. System level of organization

50. Social level of organization

51. 1.7 SOCIAL LEVEL OF ORGANIZATION A population is a number of individuals of the same species which occupy a particular area at the same time. Individuals form a society if they exhibit some organization in which they cooperate for their mutual benefit, e.g. more successful hunting in wolves. There is division of labour which leads to differentiation of individuals in order to perform specialized functions, e.g. in honey bees: queen, drones (male bees), workers (sterile females).