Active transport

Which processes account for the absorption of ions from the soil by a plant and the absorption of glucose into the villi of a human?

May/June 2015

What processes are involved in a plant taking up ions from the soil and in glucose being taken up into the villi of a human?

May/June 2015

The graph illustrates how oxygen concentration affects the uptake of nitrate ions from the soil into a root hair cell. What conclusion can be drawn from this information?

May/June 2016

In a person, the glucose concentration in the small intestine is lower than the concentration found in the blood. Glucose is taken up by the cells of the villi. Which process is responsible for this glucose uptake?

May/June 2016

Which characteristic of root hairs indicates that ions are absorbed from the soil by active transport?

May/June 2017

Which row gives the definition of active transport?

May/June 2017

Which process requires energy released by respiration?

May/June 2018

A plant is growing in fertile soil that is well supplied with water. It takes in nitrate ions by active transport and absorbs water by osmosis. How do the concentrations of nitrate ions and water in the plant’s roots compare with the concentrations in the soil?

May/June 2018

During an investigation, scientists exposed plant roots to a chemical that prevents aerobic respiration. They found that, after the exposure, the plant roots took up nitrate ions at a slower rate. Which statement best explains this result?

May/June 2021

Which of these statements about active transport are correct?

May/June 2021

The statements below are about how substances move into and out of cells. 1 Energy from respiration is needed. 2 Energy from respiration is not needed. 3 The movement takes place down a concentration gradient. 4 The overall movement is from a region of higher concentration to a region of lower concentration. 5 The overall movement is from a region of lower concentration to a region of higher concentration. Which statements apply to active transport?

May/June 2021

The graph illustrates how oxygen affects ion uptake in two groups of barley plants. Apart from oxygen availability, both groups were grown under the same conditions. Which process is occurring to account for the difference between the two curves?

May/June 2023

The table gives the concentrations of four kinds of particle in two cells. Which particle can be transferred only by active transport between the cells in the direction stated?

May/June 2024

Molecules and ions may be transported into cells and out of cells by active transport. Which statement about active transport is incorrect?

May/June 2025

The diagram illustrates the concentration of magnesium ions in a healthy plant root hair cell and in the surrounding soil water. To keep the plant healthy, in which direction will the magnesium ions move?

Oct/Nov 2015

Describe how ion absorption in plants compares with glucose uptake in humans.

Oct/Nov 2016

Which transport of a substance in plants needs energy?

Oct/Nov 2017

A seedling is placed in a solution containing potassium ions, with its roots immersed, and is then left for 48 hours. The table shows the relative concentrations of the potassium ions. At the beginning of the experiment: concentration of potassium ions in the solution = 20, in the root hair = 15. After 48 hours: concentration of potassium ions in the solution = 18, in the root hair = 35. By what process did the potassium ions enter the cell?

Oct/Nov 2018

Explain what each of the following terms means and give one example of each in either a plant or an animal: diffusion active transport

Oct/Nov 2018

Which process takes place by active transport?

Oct/Nov 2019

Which of the following statements about active transport in root hair cells are correct?

Oct/Nov 2019

An experiment was used to determine the rate at which plants absorb magnesium ions from solution. One plant was treated with a poison that prevents respiration, whereas another plant was left untreated. The graph shows the results. By what process are the magnesium ions being taken up by the plants at points N and P?

Oct/Nov 2020

An experiment investigated the speed at which plants absorb magnesium ions from a solution. One plant was treated with a poison that prevents respiration, while the other plant was kept unchanged. The graph displays the outcomes. How are the magnesium ions being taken up by the plants at points N and P?

Oct/Nov 2020

Which row is correct for active transport?

Oct/Nov 2022

Which process is responsible for transporting nitrate ions into the cell shown?

Oct/Nov 2022

Which row shows how ions and molecules are transported by active transport?

Oct/Nov 2023

The table presents the absorption rates of two different sugars, arabinose and glucose, in living and dead intestines. In each case, the sugar concentrations inside the intestines were identical. What are the main methods by which arabinose and glucose are absorbed in living intestine?

Oct/Nov 2023

The table gives the relative concentrations of two mineral ions in a root cell and in the water in the soil surrounding the plant root. Water around root: magnesium ions $23$ arbitrary units, nitrate ions $19$ arbitrary units. Inside root cell: magnesium ions $2475$ arbitrary units, nitrate ions $1306$ arbitrary units. What is required for the plant root to raise the concentration of the mineral ions in its cells?

Oct/Nov 2023

Scientists have reached the conclusion that the uptake of mineral ions in plants needs energy released by respiration. Which observation provides the strongest support for this conclusion?

Oct/Nov 2024

Which movement of a substance in a plant needs the plant to supply energy?

Oct/Nov 2024

Which statements concerning active transport are correct?

Oct/Nov 2024

Which process involves molecules moving against a concentration gradient?

Oct/Nov 2025