Question 186:

• JAMB 1980

if three 30 cm lengths of glass tubes are tightly packed with clay, sand and loamy soils respectively and then stood in a beaker of water for one week, the level of water will be

A. Lowest in the tube with clay
B. The same in all tubes
C. Lowest in the tube with loamy soil
D. Highest in the tube with sandy soil
E. Lowest in the tube with sandy soil

Question 187:

• JAMB 1980

If a baby is a female, her mother's ovum must have been fertilized by a sperm carry the chromosome

A. X
B. XY
C. XX
D. YY
E. Y

Question 188:

• JAMB 1980

Leguminous plants, e.g Mucana, are usually planted in cultivated farmlands because they

A. Enrich the soil with phoshates
B. Provide animals with food
C. Enrich the soil with organic nitrogen
D. Protect the soil from being over-heated
E. Protect the micro organisms in the soil

Question 189:

• JAMB 1980

During thunderstorms the energy of lightning discharge causes

A. Oxygen and nitrogen to combine
B. More carbon dioxide to be formed
C. Nitrites to be converted to nitrates
D. Nitrates to be converted to nitrogen
E. Death

Question 190:

• JAMB 1980

A few grams of dried soil were first heated until red hot and then further heated until no more smoke was released. This experiment was to determine

A. Amount of water in soil
B. Percentage of water in soil
C. Presence of humus in soil
D. Resistance of laterities to heat
E. Release of smoke from the soil