Transport in cells：練習題

A student calculates the surface area to volume ratio for four different cubes to model the efficiency of diffusion. Which ratio would belong to the organism that can most easily meet its needs through diffusion alone across its outer surface?

A student investigates the rate of water uptake in a plant shoot. The shoot is placed in a potometer and exposed to different environmental conditions.
The data collected shows that at \(20^{\circ}\text{C}\), the bubble in the potometer moved \(15\text{ mm}\) in \(10\text{ minutes}\). When the temperature was increased to \(30^{\circ}\text{C}\), the bubble moved \(24\text{ mm}\) in the same time period.
Calculate the rate of water uptake at \(30^{\circ}\text{C}\) in \(\text{mm/min}\).

A group of students investigated the surface area to volume ratio of three different sized cubes representing cells.
Cube A has a side length of \(1\text{ cm}\).
Cube B has a side length of \(2\text{ cm}\).
Cube C has a side length of \(4\text{ cm}\).
Which of the following statements correctly explains the relationship between cell size and the need for a specialized exchange surface?

Which process is responsible for the movement of mineral ions from very dilute solutions in the soil into plant root hair cells?

A student investigates the change in mass of potato cylinders in different sugar solutions. A cylinder with an initial mass of \(2.50\text{ g}\) is placed in a concentrated sugar solution. After 24 hours, its final mass is \(2.15\text{ g}\).

Calculate the percentage change in mass.

Explain how lungs in mammals are adapted for efficient gas exchange by increasing the effectiveness of an exchange surface.
Your answer should mention at least three specific structural adaptations.

The alveoli in the lungs are adapted for gas exchange. Explain how having a ventilation system and an efficient blood supply increases the rate of diffusion of oxygen into the blood.

Calculate the surface area to volume ratio of a cube-shaped model of a single-celled organism where each side length is \(2\text{ cm}\).