TESTS

Soil is the outermost layer of the earth’s crust capable of sustaining 1ife. The size of gravel range from;

A. 0.2 – 2mm

B. 2mm and above

C. 0.02 – 2mm

D. 0.002mm – 0.02mm

E. 0.002mm and below.

Soil profile is a description of the stratification of the soil of a place into different, more or less horizontal layers called horizons. Part labeled II is in the figure below is;

A. B – horizons
B. A – horizons
C. C – horizons
D. All above
E. Alternate A and B only

The part labeled III is mainly composed of;

A. Weathered rock materials, which are yet to be incorporated into the soil proper.

B. Humus

C. Organic matter

D. Mineral fragment and organic matter

E. All above

Physical properties of soils include;

A soil texture,

B. soil structure,

C. soil pH,

D. salinity,

E. Alternate A and B are correct.

The beneficial role of soil micro-organisms include:

A. Decomposition of organic matter.

B. Helping in the cycling of nutrient materials in natural ecosystems.

C. Taking part in soil forming activities involved in biological weathering.

D. They constitute the primary producers of soil ecosystem.

E. All above.

Factors influencing soil fertility are;

A. Climatic condition of the locality

B. The topography of the soil

C. Depth of the soil

C. Soil texture

E. All above.

In a given habitat, 90 beetles were captured, marked with a spot of paint and released. After 2 months some beetles numbering 45 were captured marked and released again the second time from the same habitat. After a further 1 month, some 15 beetles with marked shells were recaptured. The size of the population is;

A. 30

B. 90

C. 45

D. 15

E. 60

The figure below shows a logistic growth curve of a certain population. The population of these generation increase rapidly, multiplying every few generations at;

A. A

B. B

C. C

D. Both A and B

E. None above

Factors affecting population size includes;

A. Competition

B. Predation

C. Migration

D. Diseases

E. All above

The main methods of birth control are;

A. Use of contraceptive devices especially condoms

B. Use of contraceptive chemicals such as the contraceptive pill

C. Use of intrauterine devices

D. Sterilization of males and females

E. All above

Aquatic environment includes;

A. Marine habitat

B. Freshwater habitat

C. Estuarine habitat

D. All above

E. None above

Flowing freshwater such as rivers, streams and springs are termed;

A. Lotic

B. Lentic

C. Estuaries

D. Bogs

E. None above

General types of adaptations shown by organisms includes:
A. Morphological adaptations
B. Physiological or functional adaptations
C. Behavioral adaptations
D. All above
E. None above

Some animal adaptations in the Tundra biome includes;

A. Migration

B. Dormancy or Hibernation

C. Adaptations of body size and shape

D. Shorter body appendages

E. All above

The figure below shows a profile of a tropical rainforest. The roman numeral ( I ) indicates;

A. Shrubs

B. Saplings

C. Upper canopy

D. Under storey

E. None above

Root adaptations shown by tropical rainforest trees are mostly aimed at giving support to plants. The main adaptation is the development of different types of adventitious roots from the stems. The adventitious root shown in the diagram below is;

A. buttress roots,

B. stilt roots,

C. prop roots,

D. clasping roots.

E. None above

Shown below is a cross between two true-breeding plants, one with yellow seeds and the other with green seeds to produce F1 offspring one of which is then selfed to produce F2 offspring plants. The offspring shown below is a

A. Female gamete

B. Male gamete

C.Both male and female

D. All above

E. None above

In humans the” sex chromosomes” in men consist of two;

A. X chromosomes

B. Y chromosomes

C. X and Y chromosomes

D. Alternate B and C are correct

E. All above

Alternative term for homozygous

A. Allele

B. Genotype

C. Phenotype

D. Dominant

E. True-breeding

An allele expressed in heterozygotes

A. F₁

B. F₂

C. Genotype

D. Dominant

E. Phenotype

An allele only expressed in homozygotes

A. recessive

B. genotype

C. F₂

D. F₁

E. None above

Having two different alleles of a given gene

A. Homozygous

B. Heterozygous

C. Recessive

D. Allele

E. Dominant

Having two of the same allele

A. Homozygous

B. Heterozygous

C. Recessive

D. Allele

E. Dominant

One of a number of forms a gene can take

A. F₁

B. F₂

C. Allele

D. Genotype

E. recessive

Produced by inbreeding the F₁ generation

A. allele

B. F₂

C. F₁

D. True-breeding

E. Genotype

Result of a cross between two pure-breeding varieties

A. F₂

B. F₁

C. Allele

D. Phenotype

E. Genotype

The genetic makeup of an organism

A. Phenotype

B. Recessive

C. Dominant

D. Genotype

E. None above

The physical characteristics of an organism

A. Dominant

B. Allele

C. Recessive

D. Phenotype

E. Genotype