Biology 2013 Jamb Examination
Biology 2013 Jamb Examination
Question 21
Oestrogen is a hormone that is synthesized in the
Oestrogen is produced primarily in the ovaries and plays a critical role in regulating the female reproductive system, secondary sexual characteristics, and menstrual cycle in humans.
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Question 22
Which of the following is a waste product of an insect?
Insects excrete uric acid as a nitrogenous waste because it conserves water. This adaptation is particularly useful for terrestrial insects to survive in dry environments.
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Question 23
The main structure in vertebrates that supports and protects the body is the
The vertebrate skeleton provides structural support, protects internal organs, and facilitates movement. Bones act as levers, while ligaments and muscles work together to maintain stability and mobility.
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Question 24
The chitin in the exoskeleton of many arthropods is strengthened by
Calcium compounds incorporated into chitin strengthen the exoskeleton, providing rigidity and protection against predators and environmental stress for arthropods like crabs and insects.
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Question 25
The transfer of pollen grains from the anther to a stigma is
Pollination is the process of transferring pollen from the male anther to the female stigma. This is essential for sexual reproduction in flowering plants, enabling fertilization and seed formation.
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Question 26
The male reproductive organ of a flower is the
The stamen is the male reproductive organ of a flower, consisting of an anther and filament. The anther produces pollen grains which are necessary for fertilization of ovules in the carpel.
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Question 27
The blood circulatory system of vertebrates consists of
The vertebrate circulatory system includes the heart, arteries, veins, and capillaries. This system enables the transport of nutrients, oxygen, hormones, and wastes throughout the body efficiently.
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Question 28
A plant tissue that carries water and mineral salts is the
Xylem is a vascular tissue responsible for transporting water and dissolved minerals from the roots to other parts of the plant. It also provides mechanical support to stems and leaves.
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Question 29
Which of the following helps in the clotting of blood?
Platelets are small cell fragments that play a critical role in blood clotting. They aggregate at injury sites, form plugs, and release chemicals that trigger the clotting cascade.
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Question 30
Which of the following forms about 55% of the volume of the blood in man?
Plasma forms about 55% of human blood, consisting mostly of water with dissolved proteins, nutrients, hormones, and waste products. It serves as a transport medium for cells and substances.
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Chemosynthetic organisms are capable of manufacturing their food from simple inorganic substances through the process of?
I. High thermal capacity.
II. High sensitivity.
III. Easy readability.
IV. Accuracy over a wide range of temperature.
From the statement above, the qualities of a good thermometer are