The group mollusca is characterized by the presence of
Respondre
(D)
Soft, non-segmented
3
A virus can sometimes be regarded as a living organism because it
Respondre
(C)
reproduces in living cells
4
A mayor difference between plants and animals is that
Respondre
(A)
there is free movement in animals while this is limited in plants
5
Which of the following adaptation is no found in fruits and seeds dispersed by the win '?
Respondre
(B)
Spongy coats
6
The main similarity between unicellular and multicellular organisms is that both
Respondre
(A)
perform all life activities
7
One important characteristic of green plants is that they
Respondre
(C)
are autotrophic
8
A serious disadvantage of complexity in higher organisms is
Respondre
(A)
a high demand for food and energy
9
Which of these organs can be considered vestigial in humans but functional in other mammals? The
Respondre
(B)
appendix
10
Which of the following pairs of organisms are photosynthetic?
Respondre
(C)
Chlamydomonas and Euglena
11
Which of the following pairs of organisms exist as colonies?
Respondre
(B)
Pandorina and Volvox
12
Which of the following Best explains why It is difficult to see clearly in dim light?
Respondre
(C)
Too little light reaches the retina and so the cones may not be stimulated at all
13
In active transport, molecules move against a concentration gradient, therefore
Respondre
(A)
molecules move from a region of low concentration to a region of high concentration
14
Which of the following substance pass through the root cell membrane by osmosis?
Respondre
(D)
water
15
Which of the following statements defines plasmolysis?
Respondre
(C)
Shrinking away of the cytoplasm from the plant cell wall
16
Raw materials required by green plants to manufacture their food are
Respondre
(B)
inorganic substances
17
The role of ATP include all the following activities except
Respondre
(D)
producing water during aerobic respiration
18
The basis of growth involves the following processes except
Respondre
(A)
cell reduction
19
Which of the following statements is true about movement of the forearm? In
Respondre
(B)
bending the arm, the biceps contract and the triceps relax
20
Only specially adapted micro-organisms are found in
Respondre
(A)
salty water
21
Which of the following organisms causes syphilis?
Respondre
(C)
Treponema pallidlum
22
In plant respiration occurs in
Respondre
(D)
all living cells
23
A faster colour change of a dry cobalt chloride paper affixed to the lower surface of a leaf than the upper one, indicates that
Respondre
(B)
the lower surface of the leaf has more stomata
24
Which of the following takes place when a person’s body temperature rises above 37oC
Respondre
(C)
Sweating and vasodilation
25
Which of the following glands secretes a substance into the blood stream of a frightened person?
Respondre
(A)
Adrenal glands
26
Reading the verdict of a case by a judge or magistrate is an example of
Respondre
(D)
a voluntary action
27
Which of the following describes an example of fertilization in higher organisms?
Respondre
(A)
Fusion of sperm and egg nuclei
28
When both ovaries of the human female ovulate simultaneously and both ova are fertilized, then
Respondre
(B)
fraternal twins are produced
29
Which of the following statements is not true of the light stage of photosynthesis?
Respondre
(C)
Carbon (IV) oxide is reduced by hydrogen atoms in NADPH2
30
Which of the following elements is required in large amounts by plants
Respondre
(D)
Phosphorus
31
Which of the following substances has the highest amount of energy in joules per unit weight?
Respondre
(C)
Fats
32
Which of the following elements is required in large amounts by plants
Respondre
(D)
Phosphorus
33
Which of the following juices contains the enzyme ptyalin?
Respondre
(D)
Saliva
34
Trees in savannah habitats usually have heavy thick bark which mainly
Respondre
(A)
reduces the rate of transpiration
35
In the marine food web, the source of energy to the producer comes from
Respondre
(C)
sun
36
A population is best described as
Respondre
(A)
a group of the same species of organisms living together
37
Possession of strong adhesives is a feature of animals living in/on
Respondre
(B)
rocky shores
38
A stable self-sustaining environment produced by an interaction between the biotic and abiotic components is best described as
Respondre
(C)
an ecosystem
39
Which of the following factors is not associated with aquatic habitats?
Respondre
(D)
Edaphic
40
Which of the following instruments is used to measure the speed of a stream?
Respondre
(A)
Simple float
41
In an ecosystem the organism which changes light energy into stored chemical energy is the
Respondre
(C)
producer
42
Which of the following processes does not contribute to the maintenance of the nitrogen content of the soil?
Respondre
(B)
Denitrification
43
Which of the following organisms is well adapted for fluid feeding?
Respondre
(B)
Mosquito
44
The density-dependent factors that operate to regulate a population size may include the following except
Respondre
(B)
fire outbreak
45
Which of the following infections is unlikely to respond to antibiotic treatment?
Respondre
(C)
Measles
46
Algal bloom depletes oxygen content of bodies of water polluted by
Respondre
(C)
raw sewage disposal
47
Conservation of wild life is necessary mainly because
Respondre
(D)
it helps to prevent extinction of species
48
Which of the following is not a means of conservation?
Respondre
(D)
Burning of vegetation before cropping
49
Which of the following statements about mutation is true?
Respondre
(B)
The genotype is affected
50
Variation which exhibits a wide range from one extreme to the other with very little difference between the intermediates is described as
Respondre
(C)
continuous
51
Which of the following is an example of physiological variation?
Respondre
(A)
Blood groups
52
A person with blood group B can only donate blood to individuals with blood groups
Respondre
(B)
B and AB
53
If the pink colour of a petal is dominant over white what would be the colour of the flower of the F generation when a pure pink flowered plant is crossed with a white flowered plant?
Respondre
(B)
Pink
54
If two parents are sickle cell carriers then their genotypes would be
Respondre
(C)
HbA HbS and HbA HbS
55
Which disease is sex-linked and mainly afflicts male offspring?
Respondre
(B)
Haemophilia
56
In a living cell, factors which are responsible for inheritance are located
Respondre
(C)
on the chromosomes
57
Which of the following is not a correct base pairing on the DNA strand?
Respondre
(D)
Uracil, Thymine
58
Which of the following organisms is a social insect?
Respondre
(B)
Honey bee
59
Territoriality is a phenomenon among
Respondre
(C)
male animals with a group of females
60
A honey bee worker communicates with others on locating a source of food by
