Download Cell organization and Diffusion

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STUDY.
KS4
SCIENCE
Cells, tissues & Organs
Cell Organisation
This Study Pack aims to cover:
1. Diffusion in cells
2. Cell organisation.
SB21
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compiled resources based on the UK National Curriculum covering the Primary and Secondary Frameworks
including SATs and GCSE examinations.
Student Name
Contents
Diffusion and Cell organisation Notes
2-7
Practice questions
8-15
Exam questions
16-18
Mark scheme
19-22
1
2
Diffusion in Organisms
Dissolved substances have to pass through the cell membrane to get into or out of a cell. Diffusion is
one of the processes that allows this to happen.
Diffusion occurs when particles spread. They move from a region where they are in high concentration
to a region where they are in low concentration. Diffusion happens when the particles are free to
move. This is true in gases and for particles dissolved in solutions. Particles diffuse down a
concentration gradient, from an area of high concentration to an area of low concentration. This is how
the smell of cooking travels around the house from the kitchen, for example.
Examples of diffusion
Two examples of diffusion down concentration gradients
location
particles move
from
to
gut
digested food products
gut cavity
blood in capillary of villus
lungs
oxygen
alveolar air space
blood circulating around the lungs
Remember, particles continue to move from a high to a low concentration while there is a
concentration gradient.
In the lungs, the blood will continue to take in oxygen from the alveolar air spaces provided the
concentration of oxygen there is greater than in the blood. Oxygen diffuses across the alveolar walls
into the blood, and the circulation takes the oxygen-rich blood away.
3
4
Cells,
5
6
Cells and tissue and organs
Multicellular organisms usually contain differentiated cells, adapted for specific functions.
Tissues consist of groups of similar cells. Organs contain different tissues, working together
to carry out particular functions. Organ systems contain different organs. The different
organ systems work together in an organism.
Tissues
During the development of a multicellular organism, cells differentiate so that they can carry out
different functions. Differentiation is the process by which a cell becomes a specialised type of cell.
A tissue is a group of specialised cells that have a similar structure and function. The table shows
some examples of tissues and their functions.
Types of tissues and their functions
Tissue
Function
Muscular tissue
Contracts, bringing about movement
Glandular tissue
Produces substances such as enzymes and hormones
Epithelial tissue
Covers some parts of the body
Organs
Organs are made of tissues. A particular organ may contain several different tissues. For example, the
stomach is an organ that contains:

Muscular tissue - to churn the food and other contents of the stomach

Glandular tissue - to produce digestive juices including acid and enzymes

Epithelial tissue - to cover the inner and outer surfaces of the stomach
The stomach is one of the organs that form the digestive system. The stomach contains various
tissues, and each tissue is made of a particular type of cell. In order of increasing size and complexity:
cells → tissues → organ (the stomach) → organ system (the digestive system)
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Worksheet 1
Diffusion
8
Tissue and organs worksheet 2
9
Organ systems worksheet 3
10
Cells tissues and organs
1
The diagram shows a plant cell.
a
Identify the structures listed. Choose the correct letter A, B, C, D or E for each structure.
i
nucleus
...................................................................................................................................
ii
(1)
chloroplast
...................................................................................................................................
(1)
iii cell wall
...................................................................................................................................
b
(1)
Animal cells are different from plant cells.
Give the letters of the two parts that are also found in animal cells.
...................................................................................................................................
c
(2)
What is a tissue?
...................................................................................................................................
...................................................................................................................................
2
(2)
The parts of plant cells have important functions. List A contains names of cell parts. List B
lists some functions of cell parts.
Match each cell part to its correct function.
List A
List B
nucleus
controls entry of
materials into cell
(4)
11
mitochondria
produce protein
chloroplasts
release energy
ribosomes
controls cell activities
absorb light for
photosynthesis
3
Plant and animal organs contain tissues.
a
Name one example of a plant tissue and describe its function.
...................................................................................................................................
...................................................................................................................................
b
i
Name one example of an animal tissue.
...................................................................................................................................
ii
(2)
(1)
Give an example of an organ where this tissue would be found.
...................................................................................................................................
(1)
iii What is the function of the tissue you have named?
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
4
(1)
The diagram shows four ways in which molecules may move into and out of a cell. The dots
show the concentration of molecules.
a
Name the cell structure that controls the movement of materials into or out of cells.
...................................................................................................................................
(1)
12
b
i
Name the process illustrated by A and B.
...................................................................................................................................
ii
(1)
Explain the direction of the arrows in A and B.
...................................................................................................................................
...................................................................................................................................
5
(2)
The diagram shows a yeast cell.
a
Identify the parts labelled A and B.
...................................................................................................................................
...................................................................................................................................
b
(2)
The cytoplasm also contains mitochondria and ribosomes.
What is the function of these structures?
...................................................................................................................................
...................................................................................................................................
c
(2)
Suggest what is found in the vacuole.
...................................................................................................................................
(1)
13
6
In this question you will be assessed on using good English, organising information clearly and
using specialist terms where appropriate.
The digestive system is a group of organs which changes food from insoluble into soluble
molecules. Soluble molecules can be absorbed into the blood stream. Some food cannot be
digested.
Describe the functions (jobs) of the organs in the digestive system.
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
(6)
Diffusion in organisms
1. Explain how oxygen and carbon dioxide diffuse into the blood in the lungs.
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................... 4 marks
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2. Explain how nutrients are absorbed in the blood in the small intestine?
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................... 4 marks
15
Exam Questions
Q1.
(a) The diagrams show cells containing and surrounded by oxygen molecules.
Oxygen can move into cells or out of cells.
Into which cell, A, B, C or D, will oxygen move the fastest?
Write your answer, A, B, C or D, in the box.
(1)
(b)
Draw a ring around the correct word to complete each sentence.
diffusion
(i)
Oxygen is taken into cells by the process of
osmosis
.
respiration
(1)
breathing
(ii)
Cells need oxygen for
photosynthesis
.
respiration
1)
membranes
(iii)
The parts of cells that use up the most oxygen are the
mitochondria
.
nuclei
(1)
diffusion
(iv)
Some cells produce oxygen in the process of
photosynthesis
respiration
.
(1)
(Total 5 marks)
16
Q2.
The diagram shows a cell from the lining of the lung. This cell is specialised to allow gases
to pass through quickly.
(a)
Use words from the box to label structures A, B and C.
cell
membrane
chloroplast
cytoplasm
mitochondria
nucleus
(3)
(b)
(i)
Which feature of this cell allows oxygen to pass through quickly?
Put a tick (
) in the box next to your choice.
It is thin.
It has a large nucleus.
It has many mitochondria.
(1)
(ii)
Complete the sentence by drawing a ring around the correct answer in the box.
diffusion
Oxygen passes through this cell by
osmosis
respiration
(1(Total 5 marks)
Q3.
The drawing shows part of a root hair cell.
(a)
Use words from the list to label the parts of the root hair cell.
cell membrane
cell wall
cytoplasm
nucleus
vacuole
(4)
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Q4.
(a)
The diagram shows four ways in which molecules may move into and out of a cell. The dots
show the concentration of molecules.
The cell is respiring aerobically.
Which arrow, A, B, C or D, represents:
(i)
(ii)
molecules?
movement of oxygen molecules;
....................
movement of carbon dioxide
....................
(2)
(b)
Name the process by which these gases move into and out of the cell.
.....................................................................................................................................
(1)
(c)
Which arrow, A, B, C or D, represents the active uptake of sugar molecules by the cell?
.....................................................................................................................................
Explain the reason for your answer.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 5 marks)
Q5.
The diagram shows a group of muscle cells from the wall of the intestine.
(a)
On the diagram, use words from the box to name the structures labelled A, B and C.
cell membrane
cell wall
chloroplast
cytoplasm
nucleus
(3)
(b)
How are these muscle cells adapted to release a lot of energy?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 5 marks)
18
Mark scheme
M1.
(a)
A
1
(b)
(i)
diffusion
1
(ii)
respiration
1
(iii)
mitochondria
1
(iv)
photosynthesis
1
[5]
M2.
(a)
A nucleus
1
B (cell) membrane
1
C cytoplasm
1
(b)
(i)
it is thin
1
(ii)
diffusion
1
[5]
M3.
(a) (cell) wall
(cell) membrane
cytoplasm
vacuole
for 1 mark each
(b)
(i)
4
A
(ii)
B
for 1 mark each
2
(c)
diffusion
(reject osmosis)
for 1 mark
1
[7]
M4.
(a)
(ii)
(i)
A
B
for 1 mark each
2
19
b)
diffusion
(reject osmosis)
for one mark
1
(c)
C
because uptake against a concentration / diffusion gradient
(reject osmosis)
(if C not given, then idea of movement essential)
for 1 mark each
2
[5]
M5.
(a)
A
nucleus
1
B
(cell) membrane
1
C
cytoplasm
1
(b)
any two from:
•
(contain mitochondria
•
many (mitochondria)
•
respiration (occurs in mitochondria)
2
[5]
Worksheet 1 Answers
1 diffusion, gas/solute, solute/gas, high, lower, random
2 a The oxygen moves along a concentration gradient from a region of high to low oxygen concentration.
b Folded membranes provide an increased surface area so diffusion can take place more quickly.
Worksheet 2 Answers
1 Multicellular, differentiated, specialised, function, tissue
2 a sperm – specialised cell – found individually.
b kidney – organ – several tissues working together.
c stomach – organ – several tissues working together.
3 Small intestine – villi and microvilli to increase SA (surface area) for the diffusion of dissolved food molecules from
small intestine into the blood. Any other valid points.
Lungs – many alveoli to give large surface area for exchange of oxygen and carbon dioxide.
20
Worksheet 3 Answers
1 A iii, B iv, C i, D ii.
2 An organ is a collection of several different tissues that work together to carry out a particular function in the body,
e.g. heart pumps blood around the body, the stomach collects the food you eat and continues the digestive process
(any two examples). An organ system is a number of organs which work together to carry out a major function in the
body, e.g. the digestive system which gradually breaks down insoluble food molecules into soluble molecules which
can be taken into the blood stream, and then gets rid of the waste material (any two examples).
3 Each part of the digestive system relies on the parts before it, e.g. the stomach relies on the mouth, teeth and
salivary glands to deliver chunks of chewed food, the small intestine depends on the stomach to continue the
process of digestion and then on the enzymes made by the pancreas to help with the digestive process. The large
intestine can only deal with the remains of the food which has already been digested in the small intestine and the
soluble molecules absorbed into the blood. This leaves the waste material and lots of water, so the large intestine
can absorb the water and remove faeces from the body.
21
Cells and Tissue and organs Mark scheme
1
a i D
ii C
iii A
b B and D
c Group of cells – with similar function.
3
2
Nucleus – controls cell activities.
Mitochondria – release energy.
Chloroplasts – absorb light for photosynthesis.
Ribosomes – produce protein.
4
3
a Named plant tissue, e.g. epidermal/mesophyll/xylem/phloem.
Function correctly linked to chosen tissue, covers surface/photosynthesis/
transport.
b i Correctly named animal tissue, e.g. muscular/glandular/epithelial.
(Allow other relevant answer).
ii Correct organ named, which contains named tissue, e.g. stomach.
iii Correct function for named tissue, e.g. contracts to cause
movement/produces enzymes/lines organ.
2
a (Cell) membrane.
b i diffusion
ii Molecules move from a region of higher concentration to a region of
lower concentration.
1
1
a A  nucleus, B  cell wall.
b Mitochondria – release energy/respiration.
Ribosomes – produce protein.
c Solution/liquid/(cell) sap or description e.g. water and sugar.
2
2
4
5
2
2
1
1
1
2
1
6
Marks awarded for this answer will be determined by the standard of the scientific response as well as the
Quality of Written Communication (QWC). There are no discrete marks for the assessment of written
communication but QWC will be one of the criteria used to assign the answer to an appropriate level.
5-6
There is a clear and detailed description referring to most of the key organs in the digestive system and
their functions, including 5–6 points from the examples below. The answer shows almost faultless
spelling, punctuation and grammar. It is coherent and in an organised, logical sequence. It contains a
range of appropriate or relevant specialist terms used accurately.
There is a description of at least three organs and their functions with 3–4 points from the examples
below. There are some errors in spelling, punctuation and grammar. The answer has some structure and
organisation. The use of specialist terms has been attempted, but not always accurately.
There is a brief description of the functions of at least two organs, which has little clarity and detail, with 1–
2 points from the examples below. The spelling, punctuation and grammar are very weak. The answer is
poorly organised with almost no specialist terms and/or their use demonstrating a general lack of
understanding of their meaning.
No relevant content. (0 marks)
Examples of biology points made in response:
• Glands produce digestive juices
• Salivary glands
• Pancreas
• Digestion occurs in the stomach and small intestine
• The liver produces bile
• The soluble food is absorbed in the small intestine
• Water is absorbed from the undigested food
• In the large intestine.
3-4
1-2
0
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