2010 Biology NECO Past Questions

Hint

1a.(i) Name FIVE unicellular organisms.

1. Amoeba
2. Paramecium
3. Euglena
4. Chlamydomonas
5. Trypanosome
6. Trichonympha

(ii).     Explain the term locomotion.

is the movement of the whole organism from one place to another. Animals generally move their whole bodies and in most cases with special locomotory organs like legs, wings, fins , etc. locomotion is general in animals but rare in plants.

(iii).    State FOUR factors that affect diffusion.

1. State of matter: diffusion is faster in a gaseous state than in a liquid state
2. Size of molecules: the smaller the molecules the faster the diffusion
3. Temperature: the higher the temperature, the higher the rate of diffusion. This is because of the increase in motion of the molecules
4. Concentration gradient: this is the relative difference in concentration of a substance in two areas. The greater the concentration gradient, the greater the rate of diffusion

b.(i)    List FOUR types of placentation in flowering plants.

1. Axile placentaion
2. Marginal placentaion
3. Parietal placentation
4. Free-central placentation
5. Basal placentation
6. Apical placentation

(ii)      State FOUR agents of fruits dispersal.

1. Animals
2. Wind
3. Explosive mechanism
4. Water

Hint

2a.(i) What is sexual reproduction?

Sexual reproduction is the fusion of male and female gametes from two different individuals to form a zygote which later develops into embryo or organism

(ii) List THREE secondary sexual characters each in

–  Boys

1. Development / growth of pubic hairs
2. Deeper voice / deepening (breaking) of voice
3. Growth of hairs on other parts of the body (beard on the face)
4. Enlargement of penis and testis
5. Muscular development

–  Girls

1. Growth of pubic hair
2. Development of mammary glands (breasts)
3. Enlargement of uterus (womb) and other parts of the reproduction system
4. Broadening of the hips and laying down of extra fat in parts of the body

b.(i)    What is a vector?

Vectors are animals that carry and spread micro-organisms which cause diseases, but remain unaffected by the diseases

(ii)   Mention FIVE examples of vectors.

1. Mosquito
2. Housefly
3. Tse-Tse fly
4. Snail
5. Blackfly

c.(i)    State THREE types of heterotrophic nutrition.

1. Holozoic nutrition: The organism feeds on the bodies of plants and or animals. The complex organic food material is digested into simpler substances and absorbed before the substances can be utilized.

2. Saprophytic Nutrition: The organism feeds on dead organic matter, digests it extracellularly and absorbs the products of digestion. Such an organism is a saprophyte.

3. Parasitic Nutrition: the organism known as parasite lives in or on another organism (host) and feeds on or at the expense of the host.

4. Symbiotic Nutrition: this is a form of feeding in which two organism live in close association with each other for the benefit of both organism e.g. lichen is an association between an algae and a fungus.

(ii)      Name TWO organs in mammals that are involved in homeostasis.

1. Liver
2. Kidney
3. Skin

Hint

3a.(i) Name the FOUR chambers of the mammalian heart.

1. Right Auricle
2. Left Auricle
3. Right Ventricle
4. Left Ventricle

(ii)      Explain pulmonary circulation.

Pulmonary circulation involves the movement of blood between the heart and the lungs. In other words, it involves the movement of blood from the heart to the lungs for oxygenation.

As the heart muscles contrast deoxygenated blood flows from the right ventricle through the semi-lunar valves into the pulmonary artery  which supplies the lungs      for exchange of oxygen and carbon-dioxide. Oxygenated blood from the lungs then return by the pulmonary vein to the left auricle.

b.(i)    State FOUR importance of transpiration to plants.

1. Cooling effect: Transpiration involves the evaporation of water which is a cooling process.
2. Transpiration helps move water through the xylem from the roots to the leaves and then to other parts of the plants
3. Transpiration promotes healthy growth of plants
4. Transpiration enables minerals salts dissolved in water to be transported to the leaves for the synthesis of complex substances.

(ii)      Mention FOUR stages of growth.

1. Cell division
2. Cell differentiation
3. Cell assimilation
4. Cell expansion

c.       Name the THREE types of skeleton found in organisms

• Exoskeleton
• Endoskeleton
• Hydrostatic skeleton

Hint

4a.(i) Define the term adaptation.

Adaptation are special features/characteristics that an organism posses which enables it to live/survive successfully in an environment.

(ii)      Name TWO types of parasites based on its habitat.

– Ectoparasite

– Endoparasite

(iii)     Mention THREE adaptive features of tapeworm (Taenia solium)

• Presence of hooks and suckers for attachment
• Presence of Large surface area to enhance diffusion of digested food in the small intestine
• Presence of both male and female reproductive organs allows successful sexual reproduction.
• Mature prologlottides (segments) loaded with eggs are detached and expelled with faeces of host for dispersal
• Its body wall is resistant to digestive enzymes of the host.
• Large surface area of the body allows absorption of food from the gut.

b.      State TWO methods each for the conservation of the following natural resources:

(i) Forest.

1. Establishment of forest reserve
2. Replacing felled mature trees with seedling in plantation
3. Carrying out awareness campaign against deforestation
4. Planting new forest trees (afforestation) where they have been completely destroyed.
5. Controlling plants diseases by using pesticides to kill pests.
6. Regulations made to control excessive deforestation that only mature trees should be felled.
7. Discouraging extensive use of natural forest as a source of timber since animals and some other plants are also displaced.
8. Using trained forest guards to guards the forest against intruders or to fight fires.
9. Prevention of forest fires/bush burning.

(ii) Wild life

1. Establishment of game reserves
2. Establishment of ecological gardens
3. Control of hunting to prevent extinction of some animals
4. Prohibition of killing or poaching of animals in game reserves
5. Prohibition of bush burning as this may lead to migration or displacement of wildlife
6. Prohibition of deforestation and encouragement of afforestation or reafforestation
7. Prevention of pollution to prevent the destruction of aquatic life.

c.       A pure breeding black rat (BB) was crossed with a pure breeding white rat (bb). The F₁ offspring was then crossed with the pure breeding black rat (BB). By means of crosses only, show the genotypes of the offspring in the first and second filial generations.

Pure breeding black rat (BB)

Pure breeding white rat (bb)