Introduction To Biology | Form One | High School School Biology

1. Zoology - This is a branch of biology that deals with the study of animal life
2. Botany - This is a branch of biology that deals with the study of plant life.

Other smaller branches can include:

a. Ecology - This is the study of the interrelationships between organisms and their environment
b. Genetics - This sub-branch of biology deals with the study of inheritance and variation
c. Entomology - This is the study of insects
d. Parasitology - This is the study of parasites
e. Physiology - This deals with the study of the functions of various structures of an organism
f. Anatomy - The study of the internal structure of organisms
g. Microbiology - This is the study of microorganisms
h. Bacteriology - The study of bacteria
i. Ornithology - This is the study of birds
j. ichthyology - This is the study of fishes

1. The knowledge acquired from the study of biology can be very helpful in solving environmental problems such as food shortage, poor health services, pollution and environmental degradation
2. The study of biology can grant one an entry into various careers such as medicine, veterinary medicine, animal husbandry, horticulture and dentistry
3. The study of biology leads to development of scientific skills which are very useful in life. These include skills of observing, identifying, recording, classifying, measuring, analyzing and evaluating. These skills can enable one learn how to make right choices and lead an improved life.
4. Through the study of biology man learns the causes of human, plant and human diseases and how best these diseases can be prevented and cured.
5. Biological knowledge acquired in the study of biology is very useful in enhancing international cooperation such as the Joint development of HIV/AIDS vaccine by Kenyan and British scientists.

Living things share a lot of characteristics in common. These characteristics are discussed below.

1. Nutrition
   Nutrition is the process by which living things obtain and assimilate (utilize) nutrients. lants manufacture their own food using light energy, carbon (IV) oxide, water and mineral salts through the process of photosynthesis. Animals feed on already manufactured foods from plants and other animals
2. Respiration
   Respiration is the process by which food substances are chemically broken down to release energy. The energy produced in living things is very useful as it enables the living things carry out some of their physiological processes, for growth and development, movement and repair of worn out tissues.
3. Gaseous Exchange
   This is the process by which living things exchange oxygen and carbon (IV) oxide across the respiratory surfaces. Animals always take in air rich in oxygen and give out air rich in carbon (IV) oxide. Plants, however, require carbon (IV) oxide for photosynthesis during the day. They give away oxygen as a by-product.
4. Excretion
   This is the process by which living things separate and eliminate the waste or harmful materials resulting from chemical reactions within the cells.
5. Growth and Development
   Growth refers to an irreversible increase in size and mass while development refers to the irreversible change in complexity of the structure of living things.
6. Reproduction
   This is the process by which living things give rise to new individuals of the same kind. All living things reproduce.
7. Irritability
   This is the ability of living things to perceive (detect) changes in their environment and respond to them appropriately. Response of organisms to these changes is crucial as it enables them to escape from harmful stimuli.
8. Movement
   Movement refers to change is position (displacement) of a part or parts of an organism. Movement in plants includes folding of leaves, closing of flowers and growing of shoots towards light.

- A biologist may have to collect some living things or some parts of living things for observation and analysis.
- The living things or parts of living things that are used for biological study are called specimens. - Biological studies always take place in laboratories.
- A laboratory is a building or a room that is designed and equipped for scientific studies.
- Some of the apparatus used in specimen collection are as follows.

1. Sweep net- This is used for catching flying insects.
2. Fish net- This is used for trapping small fish and other small water animals.
3. Pooter- This is used for sucking small animals from rock surfaces or barks of trees.
4. Bait trap- This is used for attracting and trapping small animals including rats.
5. Pit fall trap- This is used for catching crawling animals.
6. Pair of forceps- This is an apparatus used for picking up small crawling animals e.g. stinging insects.
7. Specimen bottles- These are bottles used for keeping collected specimen.
8. Magnifying lens- This is used to enlarge small objects. A hand lens is a common magnifying lens used in the laboratory. The magnifying power of the hand lenses is always indicated on the lens e.g. X10, X5, X8.

- While collecting specimen for observation, a biologist should play close attention to the following:

• Collect only the number of specimen you need; do not collect more than you need.
• Do not harm the specimen during the capture/collection exercise.
• Do not destroy the natural habitat of the specimens.
• Handle dangerous/injurious specimens with care

Plants	Animals
Most possess chlorophyll which gives them their green colour. Chlorophyll is very useful in the process of photosynthesis.	They lack chlorophyll pigment hence feed on already manufactured food materials.
Their cells have cellulose cell walls	Their cells lack cellulose cell walls
They respond slowly to changes in their environment	They respond quickly to changes in their environment
They are immobile	Most animals move about in search of food, shelter, and mates.
They lack specialized excretory organs.	They have complex excretory organs