Biology 2022 Jamb Examination

Parasitism is a type of symbiotic relationship where one organism (the parasite) benefits at the expense of the other (the host). The tick feeds on the cow's blood, deriving nutrition while harming the cow by causing irritation, potential blood loss, and possible transmission of diseases. Other options like commensalism involve no harm to the host, which is not the case here.

An aggregate fruit develops from a single flower that contains multiple carpels, each of which forms a small fruit that collectively makes up the aggregate fruit. Examples include raspberries and strawberries. Simple fruits develop from a single carpel, while indehiscent fruits do not open to release seeds, making B the correct answer.

The urethra serves a dual role in males: it conducts urine from the bladder during urination and also carries semen during ejaculation. The seminal vesicle and epididymis are involved in the production and storage of sperm, while the ureter transports urine from the kidneys to the bladder, not participating in reproduction.

Human blood is composed of red blood cells (for oxygen transport), white blood cells (for immunity), platelets (for clotting), and plasma (the liquid medium containing nutrients, hormones, and waste products). Water is part of plasma but not listed separately in the standard components. Hence, option D correctly lists all major components.

Acquired characteristics are traits developed during an organism's lifetime due to environmental factors, training, or effort. The wrestler's large muscles result from consistent exercise and training, not from genetic inheritance or mutation, making A correct. Inherited characteristics are genetic and present from birth, while atrophication refers to muscle wastage.

Mature mammalian erythrocytes (red blood cells) lack a nucleus to maximize space for hemoglobin, increasing their capacity to carry oxygen. Other cell types like osteocytes, neurons, and leucocytes retain their nuclei for genetic control and cell function, making C correct.

Blood group AB individuals are universal recipients because their red blood cells do not contain anti-A or anti-B antibodies in the plasma. This allows them to safely receive blood from any group (A, B, AB, or O) without risk of agglutination.

Spongy mesophyll cells are loosely packed with large intercellular air spaces, facilitating efficient gaseous exchange (O₂ and CO₂) within the leaf. Palisade mesophyll cells are tightly packed for maximum light absorption, while epidermis and vascular bundles have structural and transport roles, making C correct.

Arboreal animals are adapted to live in trees. Squirrels are excellent climbers with strong limbs and tails that aid in tree locomotion. Ducks and pigs are primarily terrestrial or aquatic, and rats are mostly ground dwellers, making A correct.

Translocation is the process by which soluble products of photosynthesis, mainly sugars, are transported from the leaves (sources) to other parts of the plant (sinks) through the phloem. Guttation is water exudation, transpiration is water loss through stomata, and transportation is a general term, making D correct.