Skip to content

Irritability

Biology

GROWTH

Growth is defined as an irreversible increase in volume, size, and number of parts, length and weight of                an organism It is an organic process which takes sometimes to accomplish. The three processes involve in growth are Cell division:- is a process by which cell increases in number and is achieved by cell division called mitosis. The synthesis of new protoplasm leading to the doubling of the chromosomes number in a process called replication before cell actually divide into two, with each daughter cell having the same chromosome as parent cell. Cell enlargement:- This is a process after cell division in which the daughter cell absorb nutrients from their surrounding which it uses to increase in mass and size. Part of the nutrient is used to generate energy while the remaining is assimilated resulting in enlargement of the cells. Cell differentiation– This process takes place after cell enlargement in which… Read More »GROWTH

Biology

CHARACTERISTICS OF LIVING THINGS

CHARACTERISTICS OF LIVING THINGS Life defined through observations of activities carried out by living things;   Nutrition Nutrition is the processes by which food/nutrients are acquired/made and utilized by living organisms. Green plants and certain bacteria make their own food. All other organisms feed on complex organic materials.   Respiration This is the breakdown of food to provide energy. The energy released is used for various activities in the organism. Gaseous Exchange – Process throw which respiratory gases (CO2&O2) are taken in and out through a respiratory surface   Excretion Excretion is the removal of metabolic wastes from the body Substances like urea, carbon dioxide (Carbon (IV) oxide) These substances are poisonous if allowed to accumulate in the body   Growth and Development Growth means irreversible change in size All organisms increase in size that is, they grow Development is irreversible change in complexity As they do so, they also… Read More »CHARACTERISTICS OF LIVING THINGS

Biology

PLANTS – RECEPTION, RESPONSE AND CO-ORDINATION

PLANTS – RECEPTION, RESPONSE AND CO-ORDINATION   Introduction The structures involved in detecting the changes may be located far away from the ones that respond. There is need for a communication system within the body. The nervous system and the endocrine system perform this function, i.e. linking the parts of the body that detect changes to those that respond to them.   Irritability Living organisms are capable of detecting changes in their internal and external environments and responding to these changes in appropriate ways. This characteristic is called irritability, and is of great survival value to the organism. Stimuli A stimulus is a change in the internal or external environment to which an organism responds. Examples of stimuli include light, heat, sound, chemicals, pH, water, food, oxygen and other organisms A response is any change shown by an organism in reaction to a stimulus. The response involves movements of the… Read More »PLANTS – RECEPTION, RESPONSE AND CO-ORDINATION

School Portal NG
error: Content is protected !!