(a) State five reasons why animals move from place to place.
(b) State one function each of the following structures found in plants:
(i) epidermis
(ii) phloem
(iii) sclerenchyma.
(c) Give two examples each of the following types of organisms:
(i) parasitic plants
(ii) saprophytes.
(d) State two adaptive features of plants which inhabit salt water swamp.
(e) State two factors each which result in
(i) increase
(ii) decrease, in population density.
(f) Mention four ways in which modern agricultural activities may threaten the survival of species.
(g) State three reasons why mitosis is important to living organisms
(h) State three causes of food spoilage.
(a) Five reasons why animals move from place to place
- To search for food.
- To find water.
- To escape from predators and danger.
- To search for a mate for reproduction.
- To seek shelter or favourable conditions (suitable temperature, breeding sites).
(b) One function each of plant structures
- (i) Epidermis: protects the inner tissues and (in leaves) reduces water loss.
- (ii) Phloem: transports (translocates) manufactured food from the leaves to other parts of the plant.
- (iii) Sclerenchyma: provides mechanical support and strength to the plant.
(c) Two examples each
- (i) Parasitic plants: mistletoe and dodder (Cassytha).
- (ii) Saprophytes: Mucor and Rhizopus (mushrooms/toadstools also acceptable).
(d) Two adaptive features of salt-water-swamp (mangrove) plants: possession of breathing roots (pneumatophores) for gaseous exchange in waterlogged mud; and viviparous germination (seeds germinate while still attached to the parent) with prop/stilt roots for support.
(e) Population density
- (i) Increase: high birth rate (natality) and immigration (or abundant food).
- (ii) Decrease: high death rate (mortality) and emigration (or disease/predation).
(f) Four ways modern agriculture threatens species survival
- Clearing of forests (deforestation) destroys natural habitats.
- Use of pesticides and herbicides kills non-target organisms.
- Bush burning destroys organisms and their habitats.
- Monoculture and drainage of wetlands reduce biodiversity; overgrazing degrades land.
(g) Three reasons why mitosis is important
- It brings about growth by increasing the number of cells.
- It enables repair and replacement of worn-out or damaged cells.
- It maintains a constant chromosome number and enables asexual reproduction.
(h) Three causes of food spoilage: activity of microorganisms (bacteria and fungi); action of enzymes in the food (autolysis); and attack by pests/insects (also moisture, heat and improper storage).
(a) Five reasons why animals move from place to place
- To search for food.
- To find water.
- To escape from predators and danger.
- To search for a mate for reproduction.
- To seek shelter or favourable conditions (suitable temperature, breeding sites).
(b) One function each of plant structures
- (i) Epidermis: protects the inner tissues and (in leaves) reduces water loss.
- (ii) Phloem: transports (translocates) manufactured food from the leaves to other parts of the plant.
- (iii) Sclerenchyma: provides mechanical support and strength to the plant.
(c) Two examples each
- (i) Parasitic plants: mistletoe and dodder (Cassytha).
- (ii) Saprophytes: Mucor and Rhizopus (mushrooms/toadstools also acceptable).
(d) Two adaptive features of salt-water-swamp (mangrove) plants: possession of breathing roots (pneumatophores) for gaseous exchange in waterlogged mud; and viviparous germination (seeds germinate while still attached to the parent) with prop/stilt roots for support.
(e) Population density
- (i) Increase: high birth rate (natality) and immigration (or abundant food).
- (ii) Decrease: high death rate (mortality) and emigration (or disease/predation).
(f) Four ways modern agriculture threatens species survival
- Clearing of forests (deforestation) destroys natural habitats.
- Use of pesticides and herbicides kills non-target organisms.
- Bush burning destroys organisms and their habitats.
- Monoculture and drainage of wetlands reduce biodiversity; overgrazing degrades land.
(g) Three reasons why mitosis is important
- It brings about growth by increasing the number of cells.
- It enables repair and replacement of worn-out or damaged cells.
- It maintains a constant chromosome number and enables asexual reproduction.
(h) Three causes of food spoilage: activity of microorganisms (bacteria and fungi); action of enzymes in the food (autolysis); and attack by pests/insects (also moisture, heat and improper storage).
