Question
▶️Answer/Explanat
Question
The graph illustrates the relationship between blood glucose levels and liver glycogen concentrations in animals after consuming different glucose meals. Which statement best explains the correlation depicted in the graph?
A. Liver cells store excess blood glucose as glycogen in response to glucagon.
B. Glucagon increases the release of glucose by liver cells to restore concentrations.
C. Insulin decreases respiration rates in liver cells for storage of excess blood glucose.
D. Liver cells respond to insulin by speeding up the conversion of blood glucose into glycogen.
▶️Answer/Explanation
Ans. D
Liver cells respond to insulin by accelerating the process of converting blood glucose into glycogen, a stored form of glucose. When blood glucose levels are high, such as after eating, the pancreas releases insulin. Insulin then binds to receptors on liver cells, triggering a series of biochemical reactions that activate enzymes involved in glycogen synthesis. This helps lower blood glucose levels by storing excess glucose as glycogen in the liver, which can be released later when the body needs energy.
Question
Which substances are absorbed by the villi in the small intestine?
A. Glucose, lactose and amino acids
B. Vitamins, polypeptides and fructose
C. Glycerol, fructose and phosphate
D. Fatty acids, maltose and fructose
▶️Answer/Explanation
Ans. C
vitamins, minerals, carbohydrates, fats, protein, and water.
The villi are finger-like projections that line the small intestine and move nutrients from the intestine’s opening into the circulatory system. The villi’s surface area is increased by the finger-like projections on the epithelial cells, called microvilli.
The villi transport nutrients into capillaries and lacteals, which are a network of fine lymphatic vessels. The nutrients are then absorbed by the body through processes like simple diffusion, facilitated diffusion, and active transport.
Question
How does auxin exert its effect on plant cells?
A. Acts directly on the cell wall, causing expansion
B. Binds to a receptor resulting in expression of genes
C. Causes the vacuole to absorb water and expand the cell
D. Causes the cell to undergo cell division
▶️Answer/Explanation
Ans:B
Question
How does auxin contribute to phototropism?
A. It increases production of light-sensitive proteins.
B. It increases growth of cells on the shaded side of the stem.
C. It inhibits growth of axillary buds.
D. It inhibits stem elongation.
▶️Answer/Explanation
Ans:B
Question
The diagram shows a plant shoot and the direction of the light which the shoot received.
What are the direction of movement and the effect of auxin in the tip of a plant shoot when receiving light from one side?
▶️Answer/Explanation
Ans:C