BALANCE IN NATURE AND FAMILY PANNING
hen population-influenced factors (abiotic and biotic) are favourable, growth is promoted but when they are unfavourable growth is retarded.
SS 2 Biology (1st, 2nd & 3rd Term)
OVERCROWDING AND FOOD SHORTAGE
OVERCROWDING This is a situation in which a population increases beyond a point called the carrying capacity where the resources (e.g. food and space) are not enough to support all… Read More »OVERCROWDING AND FOOD SHORTAGE
ECOLOGICAL SUCCESSION
The orderly change in the inhabitants of an area over time is called succession. It can also be defined as the step by step orderly and gradual replacement of communities… Read More »ECOLOGICAL SUCCESSION
POLLINATION
This is the transfer of mature pollen grains from the anther of one flower to the mature stigma of the same or another flower of the same plant or another… Read More »POLLINATION
REPRODUCTIVE SYSTEM IN PLANTS
STRUCTURES AND FUNCTIONS OF THE REPRODUCTIVE ORGANS IN PLANTS The flower is the reproductive structure of a flowering plant. It has both male and female sex organs hence it can… Read More »REPRODUCTIVE SYSTEM IN PLANTS
MALE AND FEMALE REPRODUCTIVE STRUCTURES
REPRODUCTIVE SYSTEM Most multicellular animals and plants undergo a complex form of sexual reproduction in which especially differentiated male and female reproductive cells (gametes) unite to form a single cell,… Read More »MALE AND FEMALE REPRODUCTIVE STRUCTURES
EXCRETORY SYSTEM IN MAMMALS AND PLANTS
EXCRETORY SYSTEM IN MAMMALS Mammalian lungs excrete water vapour, and C02, the liver excretes bile pigment called bilirubin, the skin excretes water, salt and urea through the sweat, and the… Read More »EXCRETORY SYSTEM IN MAMMALS AND PLANTS
EXCRETION AND EXCRETORY SYSTEM
Excretion is the process by which metabolic waste products are removed from the body of all living things. Excretion is different from egestion which is the removal of solid waste… Read More »EXCRETION AND EXCRETORY SYSTEM
RESPIRATORY SYSTEM OF MAMMALS & RESPIRATION IN PLANTS
RESPIRATORY SYSTEM IN MAMMALS The respiratory system of mammals is the most complex of all respiratory systems. It comprises of a pair of lungs enclosed in the thorax and connected… Read More »RESPIRATORY SYSTEM OF MAMMALS & RESPIRATION IN PLANTS
RESPIRATORY SYSTEM | DEFINITION, CONDITIONS, TYPES, MECHANISM, FISH, TOAD, SKIN & LUNGS
DEFINITION/PHASES OF RESPIRATION The process of respiration involves the taking in of oxygen its transport within the body of the organism, its exchange in the cells and the eventual release… Read More »RESPIRATORY SYSTEM | DEFINITION, CONDITIONS, TYPES, MECHANISM, FISH, TOAD, SKIN & LUNGS
TRANSPORT SYSTEM IN HIGHER PLANTS
In simple unicellular plant materials are exchanged by simple diffusion process between the plants and its aquatic environment. Hence there is no need for elaborate transport system. However, in higher… Read More »TRANSPORT SYSTEM IN HIGHER PLANTS
CIRCULATORY SYSTEM | BLOOD, CLOTTING, TYPES, BLOOD VESSELS, ARTERY, VEIN, HEART & ORGANS
PROTECTIVE FUNCTION OF BLOOD The blood performs two basic functions in mammals and these are: (1) Transportation of various substances and (2) Protection of body against diseases The blood defends… Read More »CIRCULATORY SYSTEM | BLOOD, CLOTTING, TYPES, BLOOD VESSELS, ARTERY, VEIN, HEART & ORGANS
TRANSPORT SYSTEM | LOWER ORGANISMS, HIGHER ORGANISM, MAMMALS, ANIMALS, PLANTS, BLOOD CELLS
Transport system is the movement of metabolic materials from various parts of an organism where they are produced and transported to other parts where such are used, stored or removed… Read More »TRANSPORT SYSTEM | LOWER ORGANISMS, HIGHER ORGANISM, MAMMALS, ANIMALS, PLANTS, BLOOD CELLS
DIGESTIVE SYSTEM | HYDRA, EARTHWORM, INSECTS, BIRD, MAN, TAPEWORM & PLANARIA
INVERTEBRATES Feeding in Hydra Digestion in Planaria Digestion in Earthworm Digestion in insects (Grasshopper) VERTEBRATES Digestion in Birds Digestion in Rabbits FEEDING IN HYDRA Hydra feeds on small aquatic… Read More »DIGESTIVE SYSTEM | HYDRA, EARTHWORM, INSECTS, BIRD, MAN, TAPEWORM & PLANARIA
MAMMALIAN TEETH
TYPES OF TEETH Human beings have two sets of teeth in their lifetime. The first set is called the milk teeth that grow when the child is few months old.… Read More »MAMMALIAN TEETH
TISSUE AND SUPPORTING SYSTEM
To carry out life processes, all organisms (plants and animals) need tissues. Tissues are group of similar cells that carry out specific functions. Skeleton is the framework of the body… Read More »TISSUE AND SUPPORTING SYSTEM
ADAPTATION
ADAPTATION Adaptation is defined as the ability of an organism to live successfully in a particular habitat as a result of its structure, appearance and behaviour. It is expected that… Read More »ADAPTATION
ECOLOGICAL MANAGEMENT
Biological Association In a community, there exist different kinds of biological associations between organisms of different species. Some of these biological associations are beneficial, some are neutral while others are… Read More »ECOLOGICAL MANAGEMENT
CONSERVATION OF NATURAL RESOURCES
CONSERVATION OF NATURAL RESOURCES Definition: Conservation is defined as the planned, control exploitation or judicious use of natural resources to ensure their continuous availability and to preserve the quality or… Read More »CONSERVATION OF NATURAL RESOURCES
ENVIRONMENTAL POLLUTION
POLLUTION Definition: Pollution is defined as the release of toxic or harmful substances into the environment by their natural forces or man and other animals to an extent that causes… Read More »ENVIRONMENTAL POLLUTION