Tag: o level Integrated Science question and answers

Iron and copper are widely used metals.  Iron and copper exist in the environment as iron ore and copper. In order to get pure iron and copper the ores must be smelted. The removal of impurities involves chemical reactions.  Iron has the following processes: extraction. Copper and iron can be combined with other metals to form alloys.  Metals can be coated to prevent rusting.

Materials in all forms, i.e. solids, liquids and gases are all made up of matter. All matter is made up of atoms. Atoms are made up of three types  particles, the protons, neutrons and electrons. Matter can exist as elements, mixtures and compounds. Materials can be classified as metals or non-metals. Some metals are more reactive than others. Some materials are acids bases or salts. Speeds of reaction are affected by temperature, concentration, surface area and the presence of catalysts.

An ecosystem is a self-contained system of interdependent organisms and their physical environment. An ecosystem has various components that may include air, water, soil, light and living organisms.

Plants of the same species are different. The difference between organisms of the same species is called variation. There are two types of variation: continuous and discontinuous. Variation is either inherited or caused by the environment. Man is interested in variation and seeks to manipulate it to produce good quality crops and livestock.  Selection is the process of eliminating individuals with undesirable characteristics.  Selection can be natural or artificial.

Reproduction is the production of young ones/offpring. Reproduction using sex cells or gametes is called sexual reproduction. Reproduction using body cells is called asexual or vegetative reproduction.  Sexual and asexual reproductions have their advantages and disadvantages. In sexual reproduction, seeds are produced. Young plants develop from seeds.

Many substances need to be transported around the body. Nutrients are transported from organs to the individual cells where they are used. Wastes are transported from the body cells to the organs where they are expelled out of the body. Mammals have circulatory systems for the movement of substances in the body. Metabolic processes are facilitated through the circulating system.

Plants are either dicotyledonous or monocotyledonous.  Seeds of dicotyledons have two cotyledons while monocotyledons have one cotyledon. Plants need a mechanism of transporting substances from one part of the plant to another. A network of xylem vessels and phloem tissues form the plant’s transport system. Water and dissolved mineral salts travel in xylem vessels and is driven by transpiration.  Sugars travel in the phloem tissue, the process is called active uptake and it requires energy to move sugars from one point to another.   Roots and stems are modified for uptake and transportation of water and mineral salts as well as dissolved food. Plants lose water through transpiration.

Processes that take place in the body require energy. The energy needed by the body is released in a process called respiration. Respiration requires food and oxygen. Respiration involves chemical reactions.  

Animal nutrition focuses on the dietary nutrients needs of animals, especially those in agriculture and food production, but can include those in zoos, aquariums, and wildlife management. There are seven major classes of nutrients: carbohydrates, fats, fibre, minerals, proteins, vitamins, and water