Explanation

Human plasma proteins consist of:

• Fibrinogen (A): involved in blood clotting
• Albumin (C): helps regulate blood volume and transport various molecules

Explanation

• In the context of phloem transport, "source" refers to the location where sucrose is produced (usually leaves).
• While "sink" refers to the location where sucrose is consumed or stored (e.g., roots, stems, fruits, and storage organs).
• A mature leaf is typically a source, not a sink, as it produces sucrose through photosynthesis.

Explanation

• The evaporation of water from the leaves, also known as transpiration, creates a negative pressure that pulls water up the xylem from the roots to the leaves.
• This process is known as the transpiration-cohesion theory.

Explanation

• Phloem is the vascular tissue responsible for transporting organic materials, such as sugars, amino acids, and other nutrients.
• Produced by photosynthesis from the leaves to the rest of the plant, including roots, stems, and fruits.

Explanation

• Bile salts are produced by the liver and stored in the gallbladder.
• They are released into the duodenum (the first part of the small intestine) to facilitate fat digestion.

Explanation

• Red meat is a good source of protein and other nutrients.
• It is not a significant source of calcium.

Explanation

The pharynx (throat) is a shared passage for both the respiratory and digestive systems.

The trachea (windpipe) and esophagus both connect to the pharynx:

• The trachea connects to the pharynx anteriorly (front) and leads to the lungs.
• The esophagus connects to the pharynx posteriorly (back) and leads to the stomach.

Explanation

• Pepsin is a proteolytic enzyme produced by the chief cells in the stomach lining.
• It breaks down proteins into smaller peptides and amino acids, initiating protein digestion in the acidic environment of the stomach.

Explanation

Vitamin A is essential for the production of rhodopsin, the visual pigment in the retina that allows us to see in low light conditions.

Explanation

• Animals that migrate long distances need a compact and energy-dense source of fuel to sustain them during their journey.
• Fat is the most energy-dense nutrient, providing approximately 9 kcal/g, compared to carbohydrates (4 kcal/g) and protein (4 kcal/g).