The smart way to improve grades

Comprehensive & curriculum aligned

Affordable pricing from £10/month

Understand Transport Systems in Multi-Cellular and Single-Celled Organisms

In this worksheet. students will understand the impact of surface area to volume ratios on diffusion in organisms and the need for transport systems.

'Understand Transport Systems in Multi-Cellular and Single-Celled Organisms' worksheet

Key stage:  KS 4

Curriculum topic:  

Curriculum subtopic:  

Difficulty level:  

Worksheet Overview

QUESTION 1 of 10

To travel from A to B, we use specially designed modes of transport like cars, and organisms move substances the same way!

 

Single-celled organisms move substances across their body surface, but when there are many cells, the volume of cells increases while the surface area stays the same, so substances have to supply more needs and travel farther, slowing transport down.

 

To increase their SURFACE AREA TO VOLUME RATIO, they've got special exchange surfaces and transport mediums to move substances around, usually using DIFFUSION.

 

1. Gas Exchange

When mammals breathe, specially designed ALVEOLI increase the surface area for diffusion in the lungs, helping to take in oxygen and remove carbon dioxide, while in plants carbon dioxide comes in for photosynthesis which makes oxygen.

 

 

2. Urea

Diffusion also helps remove waste like urea, where blood transports it from the liver to the kidneys to be excreted out of the body.

 

 

3. Dissolved Food

 

 

Food is broken in the digestive system into dissolved food molecules that diffuse into the bloodstream using MICROVILLI that increase the gut's surface area for absorption.

                          

 

4. Water transport via OSMOSIS

Osmosis is particular to the diffusion of WATER, and when plant cells are placed in a watery mixture they take water in and become TURGID, and the only thing that stops them bursting is their strong cell walls.

 

But if plant cells are placed in a low water solution, cells release water and they shrink away from the cell wall, becoming PLASMOLYSED.

 

Animals cells change shape during osmosis as they don't have cell walls, like red blood cells expanding or shrivelling up.

 

 

5. Active transport of Mineral Ions

In plants, the uptake of MINERAL IONS by root hair cells uses active transport to pull them from the low concentration in the soil into the almost full cells AGAINST the concentration gradient using ENERGY.  

After diffusion and osmosis, which other method is used to transport substances?

How many of these different substances are transported in and out of cells and the blood using DIFFUSION?

Dissolved Foods

Urea

Water

Oxygen

Both plants and mammals have very sophisticated methods of gas exchange because of the importance of effective respiration for cell survival.

Column A

Column B

In Plant Cells...
Carbon Dioxide Diffuses IN and Oxygen Diffuses OUT...
In Mammalian Lungs...
Oxygen Diffuses IN and Carbon Dioxide Diffuses OUT...

What is the journey of urea?  

Blood ⇒ Liver ⇒ Kidneys

Liver ⇒ Blood ⇒ Kidneys

Kidneys ⇒ Blood ⇒ Liver

Active transport is a method of substance transport across exchange surfaces.

Blood ⇒ Liver ⇒ Kidneys

Liver ⇒ Blood ⇒ Kidneys

Kidneys ⇒ Blood ⇒ Liver

As soon as we have more than a few cells, specially designed transport systems are needed. 

Blood ⇒ Liver ⇒ Kidneys

Liver ⇒ Blood ⇒ Kidneys

Kidneys ⇒ Blood ⇒ Liver

What structures allow the intestines and lungs to increase their surface areas? 

Blood ⇒ Liver ⇒ Kidneys

Liver ⇒ Blood ⇒ Kidneys

Kidneys ⇒ Blood ⇒ Liver

When placed in different solutions, plant cells change their shape due to the effect of osmosis.

 

Blood ⇒ Liver ⇒ Kidneys

Liver ⇒ Blood ⇒ Kidneys

Kidneys ⇒ Blood ⇒ Liver

As animal cells don't have cell walls, when they gain water they sometimes threaten to...?

Mineral Ions are actively transported into which cells?

  • Question 1

After diffusion and osmosis, which other method is used to transport substances?

CORRECT ANSWER
ACTIVE TRANSPORT
EDDIE SAYS
The movement of substances is often dependent on whether the outside environment has more or less of the desired molecule than what's inside the cell, creating a natural shift in particles to create an equal balance on both sides. Active transport takes this one step farther and uses energy to go against this natural desire for equilibrium.
  • Question 2

How many of these different substances are transported in and out of cells and the blood using DIFFUSION?

CORRECT ANSWER
Dissolved Foods
Urea
Oxygen
EDDIE SAYS
How did you get on with this question? Diffusion is used in gas exchange with oxygen and carbon dioxide in both plants and animals, but also with dissolved foods across the small intestine wall and waste products like urea. Water, however, is indeed moved by diffusion but it has its own special term for this transport called OSMOSIS.
  • Question 3

Both plants and mammals have very sophisticated methods of gas exchange because of the importance of effective respiration for cell survival.

CORRECT ANSWER

Column A

Column B

In Plant Cells...
Carbon Dioxide Diffuses IN and Ox...
In Mammalian Lungs...
Oxygen Diffuses IN and Carbon Dio...
EDDIE SAYS
Plant cells take in carbon dioxide for photosynthesis, creating oxygen which diffuses out of the cells. But in the alveoli, oxygen is needed for respiration while carbon dioxide waste is gathered in the blood from cells, escorted to the lungs and breathed out.
  • Question 4

What is the journey of urea?  

CORRECT ANSWER
Liver ⇒ Blood ⇒ Kidneys
EDDIE SAYS
When protein is broken down, any unused excess is converted into fat and carbohydrate stores, but this makes an unwanted byproduct called ammonia which has to be made into urea so it can be safely removed. Urea is therefore made by the LIVER and then diffuses into the BLOOD to be transported into the KIDNEYS to be excreted out of the body.
  • Question 5

Active transport is a method of substance transport across exchange surfaces.

CORRECT ANSWER
EDDIE SAYS
Active transport is a type of diffusion, but it's trying to fight natural concentration gradients in living beings. When cells need to move substances into an already saturated area, simple diffusion won't work, so they use ENERGY to push substances AGAINST the natural concentration gradient from an area with little to an area with a lot.
  • Question 6

As soon as we have more than a few cells, specially designed transport systems are needed. 

CORRECT ANSWER
EDDIE SAYS
Single-celled organisms can easily exchange substances across their surface because the thickness of one cell is a short distance, so diffusion is fast. In more complicated creatures like humans, many layers of cells mean more time is needed for substances to travel to all the cells around the body, and more cells mean a higher demand for nutrients. These two things together demonstrate the need for special transport systems to speed up the delivery of substances throughout organisms.
  • Question 7

What structures allow the intestines and lungs to increase their surface areas? 

CORRECT ANSWER
EDDIE SAYS
The alveoli look like cotton plants or grapes, having a bumpy formation rather than being smooth spheres, increasing the amount of surface that has contact with the blood for optimal diffusion. Microvilli also increase the surface area for dissolved food molecules to diffuse into the blood.
  • Question 8

When placed in different solutions, plant cells change their shape due to the effect of osmosis.

 

CORRECT ANSWER
EDDIE SAYS
TURGID means the plant cell is full of water and the cell wall stops it bursting like human cells. This happens when there is a lot of water around the cell, called a dilute solution, as the cell takes up water across the concentration gradient through the permeable cell wall and cell membrane. PLASMOLYSED is when the cell has lost so much water that the cell membrane starts peeling off the cell wall as the cell shrinks. A cell loses water when osmosis takes water across a concentration gradient into an area with little water. In animals, this causes shrinkage.
  • Question 9

As animal cells don't have cell walls, when they gain water they sometimes threaten to...?

CORRECT ANSWER
BURST
EDDIE SAYS
The additional support provided by the cell wall gives plant cells strength so when they take up water by osmosis they don't burst, which is a problem in humans cells like red blood cells. Well done on making it through this activity and remember to jot down any useful phrases or explanations that have helped you wrap your head around this topic!
  • Question 10

Mineral Ions are actively transported into which cells?

CORRECT ANSWER
ROOT HAIR CELLS
EDDIE SAYS
Plant cells need a high concentration of mineral ions in their cells so they use active transport to collect any remaining salts in the soil and push them into the root hair cells using energy.
---- OR ----

Sign up for a £1 trial so you can track and measure your child's progress on this activity.

What is EdPlace?

We're your National Curriculum aligned online education content provider helping each child succeed in English, maths and science from year 1 to GCSE. With an EdPlace account you’ll be able to track and measure progress, helping each child achieve their best. We build confidence and attainment by personalising each child’s learning at a level that suits them.

Get started
laptop

Start your £1 trial today.
Subscribe from £10/month.