Biology1
What is the powerhouse of the cell
MITHONIGGADRIA
What is osmosis
Flow of water when passing through a partially permeable membrane
This vitamin is required for collagen production and prevents scurvy.
Vitamin C
This tissue transports water and mineral ions.
Xylem
This enzyme breaks down starch.
Amylase
Three factors affecting transpiration rate.
Temperature, wind speed, humidity
This mineral is required for haemoglobin production.
Iron
The resistant bacterium commonly called a superbug.
MRSA
Energy currency molecule produced in respiration.
ATP
The waterproof substance strengthening xylem walls.
Lignin
The test used to determine effective antibiotics against bacteria.
Antibiotic susceptibility test
The blood vessel carrying absorbed nutrients to the liver.
Hepatic portal vein
This organ produces hydrochloric acid and pepsin.
Explain why antibiotics do not work against viruses.
Viruses lack the cellular structures and metabolic pathways targeted by antibiotics and reproduce inside host cells.
Explain why bile improves fat digestion.
By emulsification increasing surface area for lipase action?
100 for every point mentioned
Artery: Thick wall, high elasticity fibre and low lumen
Vein: Thin wall, low elasticity fibre, high lumen and valve
State two adaptations of villi for absorption.
Choose 2 from either large surface area, thin walls, and rich blood supply
The disease caused by bacterial damage to teeth.
Tooth decay
Explain two roles of fats in the human body besides energy storage.
Cell membrane formation, and organ protection?
The hard outer covering of a tooth.
Enamel
A plant is placed in hot, windy conditions with low humidity. Explain why the plant may wilt even if water is still present in the soil.
Hot temperatures increase evaporation, wind removes water vapour around the leaf maintaining a steep diffusion gradient, and low humidity further increases diffusion of water vapour out of stomata. Transpiration rate becomes faster than water uptake by the roots, causing cells to lose turgor pressure and the plant to wilt.
Explain how transpiration pull moves water upward through xylem.
Water evaporates from leaves, reducing pressure at the top of xylem, pulling a continuous column of water upward.
During vigorous exercise, a runner’s breathing rate remains high even after stopping. Explain in detail why this happens and include the role of anaerobic respiration.
During vigorous exercise, muscles require more oxygen for aerobic respiration. When oxygen supply becomes insufficient, muscles undergo anaerobic respiration, producing lactic acid and a small amount of energy. After exercise, extra oxygen is needed to transport and break down the accumulated lactic acid in the liver. This requirement is called oxygen debt, causing breathing and heart rate to remain elevated until the lactic acid is removed.
Explain oxygen debt after exercise.
Extra oxygen is required to break down lactic acid accumulated during anaerobic respiration.
This process moves food through the alimentary canal.
Peristalsis