Biology 2004 Jamb Examination

The correct answer is A. duodenum.

The gallbladder of a mammal stores bile, which is produced by the liver. This bile is then released into the digestive system through the common bile duct, which connects the gallbladder to the duodenum. The duodenum is the first part of the small intestine, and bile helps in the digestion of fats when released into this area.

The other options are related to the digestive system, but the gallbladder specifically connects to the duodenum via the bile duct.

B. Decreasing the solute concentration in the guard cells.

In an osmosis experiment, the yam tuber serves as a living semi-permeable membrane. Its cellular structure allows the selective movement of water molecules from a region of higher water potential (lower solute concentration) to a region of lower water potential (higher solute concentration), while blocking the passage of larger solute molecules like salt or sugar. 

The correct answer is D. Decrease in the volume of water inside the yam.

If the setup involves placing a yam in a salt solution, osmosis will occur. Osmosis is the movement of water from a region of lower solute concentration (inside the yam) to a region of higher solute concentration (the salt solution) through a selectively permeable membrane. As water moves out of the yam into the salt solution, the volume of water inside the yam decreases, causing it to shrink in size and lose turgidity.

The correct answer is A. embryonic development is longer in birds.

Birds' eggs contain relatively larger quantities of yolk because the yolk provides the necessary nutrients for the developing embryo during the long period of embryonic development within the egg. Since bird embryos develop entirely within the egg, they rely on the yolk for sustenance until they are ready to hatch. This is in contrast to amphibians and many reptiles, where the embryos often develop more quickly or may receive additional nutrients from the environment or the mother.

C. dicot stem and monocot roots

The correct answer is D. prolactin.

Here's why:

Prolactin is the hormone responsible for stimulating milk production in the mammary glands of nursing mothers. If a nursing mother is not producing enough milk, it likely indicates a deficiency in prolactin. This hormone is secreted by the pituitary gland and plays a crucial role in lactation.

The joints between the adjacent processes of the vertebrae (specifically the facet joints or zygapophyseal joints) are classified as sliding joints (also known as gliding or plane joints). These joints consist of flat or nearly flat articular surfaces that allow the bones to slide or glide over one another, providing the flexibility needed for the spine to bend and twist while maintaining stability.

B. lumbar vertebrae

The correct answer is C. lipases.

Lipases are enzymes that specifically catalyze the breakdown of fats and oils (lipids) into simpler absorbable compounds such as fatty acids and glycerol. This process is essential for the digestion and absorption of dietary fats in the body. Peptidases break down proteins, amylases break down carbohydrates, and hydrolases is a general term for enzymes that catalyze the hydrolysis of various compounds, but lipases are specifically involved in lipid digestion.