Biology

What is Gestation Period? The period between conception and birth is called gestation. In humans gestation takes nine months (40 weeks). The embryo differentiates into tissues and organs during this… Read More »GESTATION PERIOD

What is fertilization in animals? Fertilization is preceded by copulation in which the erect penis is inserted into the vagina. This leads to ejaculation of semen. The sperms swim through… Read More »FERTILIZATION IN ANIMALS

The female reproductive system consists of the following: Ovaries Are two oval cream coloured structures found in lower abdomen below the kidneys. Oviducts. They produce the ova. Are tubes which… Read More »REPRODUCTION IN HUMANS – HUMAN REPRODUCTIVE SYSTEM

What is reproduction in animals? Sexual reproduction involves the fusion of gametes. In animals two individuals are involved, a male and a female. Special organs known as gonads produce gametes.… Read More »REPRODUCTION IN ANIMALS

Animal dispersal Fleshy fruits are eaten by animals. Animals are attracted to the fruits by the bright colour, scent or the fact that it is edible. The seeds pass through… Read More »METHODS OF FRUIT AND SEED DISPERSAL

What is placentation? This is the arrangement of the ovules in an ovary. Marginal placentation: The placenta appears as one ridge on the ovary wall e.g. bean. Parietal placentation: The… Read More »PLACENTATION

What is pollination? This is the transfer of pollen grains from the anther to the stigma. Types of pollination Self pollination is the transfer of pollen grains from the anther… Read More »POLLINATION

What is sexual reproduction in plants? In flowering plants, the flower is the reproductive organ which is a specialised shoot consisting of a modified stem and leaves. The stem-like part… Read More »SEXUAL REPRODUCTION IN PLANTS

The process by which mature individuals produce offspring is called reproduction. Reproduction is a characteristic of all living organisms and prevents extinction of a species. There are two types of… Read More »REPRODUCTION IN PLANTS AND ANIMALS

What is Asexual reproduction? Asexual reproduction is the formation of offspring from a single parent. The offspring are identical to the parent. Types of asexual reproduction. Binary fission in amoeba.… Read More »ASEXUAL REPRODUCTION

Ecology is best studied outdoors. Students identify a habitat within or near the school compound, e.g. a flower bed. The quadrat method is used. Observation and recording of the various… Read More »BIOLOGY PRACTICAL ACTIVITIES

Ascaris lumbricoides Ascaris lumbricoides lives in the intestines of a man or pig, feeding on the digested food of the host. The body of the worm is tapered at both… Read More »HUMAN DISEASES (PARASITIC DISEASES)

The term disease denotes any condition or disorder that disrupts the steady state of wellbeing of the body. Health is a state of physical, mental and emotional wellbeing in the… Read More »HUMAN DISEASES – BACTERIAL DISEASES

What is pollution? This is the introduction of foreign material, poisonous compounds and excess nutrients or energy to the environment in harmful proportions. Any such substance is called a pollutant.… Read More »POLLUTION: DEFINITION, CAUSES, SOURCES AND CONTROLS

What is hydrophytes (water plants)? Water plants are submerged, emergent or floating. Submerged Plants The leaves have an epidermis with very thin walls and a delicate cuticle. They have no… Read More »HYDROPHYTES (WATER PLANTS)

What is population estimation methods? It is important to find or estimate the sizes of the different populations in a habitat. Direct counting or head count which involves the counting… Read More »POPULATION ESTIMATION METHODS

What is a food chain? A food chain is a linear relationship between producers and consumers. It represents the transfer of food energy from green plants through repeated stages of… Read More »FOOD CHAINS

The relationships between organisms in a given ecosystem is primarily a feeding one. Organisms in a particular habitat have different feeding levels referred to as trophic levels. There are two… Read More »INTER-RELATIONSHIPS BETWEEN ORGANISMS

What is Ecosystem? The community and the abiotic or non-living environment together make up an ecosystem or ecological system. In this system energy flow is clearly defined from producers to… Read More »THE ECOSYSTEM

To examine Bryophyta A mature moss plant is obtained. The specimen is observed using a hand -lens. A labelled drawing showing structures is made: rhizoids, set a capsule, gametophyte, sporophyte.… Read More »BIOLOGY PRACTICAL ACTIVITIES