1

S4 Biology

MULTICELLULAR ORGANISMS

Unit 2

Part B: I wan’na be like you

NAME:

CLASS:

2

Topic 1: Plant Transport No. Level Rating

R/A/G 16 N5 Plant transport: I can describe the structures of a leaf: upper epidermis, palisade mesophyll,

spongy mesophyll, vein, lower epidermis, guard cells and stomata

17 N5 Plant transport: I have investigated the movement of water and minerals through xylem vessels and

can describe their structure (lignin).

18 N5 Plant transport: I have looked at root hairs under the microscope and can describe the moment of

water through root hair cells and xylem to the leaf (transpiration).

19 N5 Plant transport: I have learned about the process of transpiration and know that it is affected by

wind speed, humidity, temperature and surface area.

20 N5 Plant transport: I have measure the rate of transpiration using a potometer.

21 N5 Plant transport: I have looked at stomata under the microscope and can describe their role in

transpiration

22 N5 Plant transport: I understand that sugar is transported up and down the plant in living phloem tissue 23 N5 I can describe the structure of phloem tissue to include phloem cells with sieve plates and

companion cells

Topic 2: Animal Transport 24 N5 Animal transport and exchange systems: I can state that mammals have blood to transport

nutrients, oxygen and carbon dioxide.

25 N5 Animal transport and exchange systems: I can state that blood contains plasma, red blood cells and

white blood cells

26 N5 Animal transport and exchange systems: I can describe how red blood cells are specialised to

transport oxygen efficiently

27 N5 Animal transport and exchange systems: I understand the role of haemoglobin and oxyhaemoglobin

in the transport of oxygen.

28 N3 KA3 Animal transport and exchange systems: I can describe the body defences against disease and the

role of vaccines

29 N3 KA3 I have learned that the body’s first line of defence is barriers to infection such as skin, tears and

mucus.

30 N3 KA3 I can state how vaccines can provide immunity to disease 31 N5 Animal transport and exchange systems: I can state that white blood cells are part of the immune

system and are involved in destroying pathogens

32 N5 Animal transport and exchange systems: I can name two main types of white blood cells: phagocytes

and lymphocytes

33 N3 KA1

/N5

Animal transport and exchange systems: I have taken part in heart dissections or used models to

examine the structures of the mammalian heart.

34 N5 Animal transport and exchange systems: I can name the chambers of the heart (left atrium, right

atrium, left ventricle, right ventricle) and describe the flow of blood through the heart.

35 N5 Animal transport and exchange systems: I can identify the blood vessels of the human body (aorta,

vena cava, pulmonary arteries, pulmonary veins)

36 N5 Animal transport and exchange systems: I can identify the coronary artery and understand its

importance to healthy functioning of the heart.

37 N5 Animal transport and exchange systems: I know the difference in structure and functions of the

different blood vessels (veins, arteries, capillaries)

Topic 3: Absorption of materials 38 N5 Animal transport and exchange systems: I understand that oxygen and nutrients from food must be

absorbed and delivered to cells for respiration

39 N5 Animal transport and exchange systems: I understand that waste materials such as carbon dioxide

must be removed from cells into the blood stream.

40 N5 Animal transport and exchange systems: I understand that tissues contain capillary networks to

exchange materials at a cellular level

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41 N5 Animal transport and exchange systems: I can describe the features of the small intestine that

allow food to be absorbed into the bloodstream (large surface area, thin walls, good blood supply,

villi)

42 N5 Animal transport and exchange systems: I can describe the features of the villus and state that

glucose and amino acids move into the bloodstream, fatty acids and glycerol move into the lacteals of

the villi.

43 N3 KA1 Animal transport and exchange systems: I have looked at the structure of the lungs 44 N5 Animal transport and exchange systems: I can describe the features of the alveoli and explain how

oxygen and carbon dioxide are exchanged through the alveolar walls.

Topic 4: Control and communication No. Level Outcome Rating

R/A/G 45 N4 I can discuss why stable conditions are important to the body in order to survive 46 N4 I can name temperature as an external factor 47 N4 I can describe the response of the body to a) increasing and b) decreasing temperature 48 N4 I have researched the causes of diabetes 49 N5 I can state the definitions of “hormone” and the “endocrine system” 50 N5 I understand the terms “target tissues” and “hormone receptor proteins”. 51 N5 I have researched the role of hormones in the body. 52 N4/N5 I have investigated diabetes and its causes including the differences between Type 1 and Type 2

diabetes.

53 N4/N5 I can name blood glucose level as an internal factor and describe how the body responds to both a)

increasing and b) decreasing concentrations

54 N5 I have investigated blood glucose regulation including the role of insulin, glucagon, glycogen,

pancreas and liver.

55 N5 I can state that the Nervous system consists of central nervous system (CNS) and nerves.

56 N4/N5 I have investigated examples of where communication pathways are used, e.g. pain receptors.

57 N5 I can state that the CNS consists of the brain and spinal cord.

58 N4/N5 I have used models to look at the structure and function of brain (N5: including cerebrum,

cerebellum and medulla).

59 N5 I have used diagrams to illustrate the three types or neurons (sensory, inter and motor).

60 N5 I know the key terms receptors, sensory input/stimuli, electrical impulses and describe how

electrical impulses carry messages along neurons.

61 N5 I have used diagrams and animations to investigate synapses and state that a synapse occurs

between neurons. I know that chemicals transfer these messages across synapses.

62 N5 I can describe the structure and function of reflex arcs and their role in protecting the body from

harm. I can state examples of reflex actions and explain their importance (e.g. blinking, iris reflex,

response to pain)

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For National 5 Biology 2020 Exam……

This is the final topic. Make sure you are revising ALL of the N5 material

from S3 AND S4. Be organised and make sure you have all your notes:

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Topic 1: Transport

In this topic we will look at how transport is important in living organisms. We

will look at how plants transport food and water to stay alive. In topic 2 we will

look at how animals transport materials around the body.

Plant Transport

Revision

1. What is the process by which plants use light energy to make food?

____________________

2. Write the word equation for this process, labelling raw materials,

products and any other requirements

Photosynthesis and plant structure

Plants need special structures to help them carry out Photosynthesis. The

leaves are the organs of photosynthesis and have special structures and

features to allow them to carry out the process efficiently.

The raw materials for photosynthesis must be delivered to chloroplasts inside

the leaves so that plants can carry out photosynthesis.

For example water and minerals must

be absorbed through special root hair cells

and is carried up to the leaves through special

tubes called _________ _________ .

The food made during photosynthesis is

transported up and down the plant through

special tissue called _____________.

Add labels to the plant to show its organs:

Leaves (Site of photosynthesis)

Roots (Absorb water and minerals)

Stem (Bundles of xylem and phloem)

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The need for transport

Match the following uses of water to the correct description (revision from Unit 1):

support transport cooling photosynthesis

The diagram below shows the structure of a leaf. Label the structures and

complete the table to show the functions of each.

Use of water Description

Water enters plant cells making them turgid

When water evaporates from the surface of a plant it carries heat away

from the plant

Hydrogen from water combines with carbon dioxide to make glucose

Minerals needed by the plant and sugars produced by photosynthesis must

be moved within the plant

Structure Function

Waxy Cuticle (1, 7)

Upper epidermis (9) & lower epidermis (4)

Palisade mesophyll (2) & spongy mesophyll (8)

Moist air space (3)

Stoma (5)

Guard cells (6)

1 9

8

2

3

7 4

5

6

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Plants have vascular tissue or “veins”. Vascular tissue is made up of bundles of

xylem and phloem. Your teacher will show you stained xylem vessels (celery) and

pictures of vascular bundles.

Draw a labelled picture of the celery cross section with stained pink bundles of

xylem and the lignified xylem vessels you have seen under the microscope:

Describe the path that water takes as it enters the plant and moves to the

leaves for photosynthesis. You should use your knowledge of osmosis in your

description and the words in the box below (Hint!).

Xylem tissue is ____________ as it is made of xylem cells which have lost

their ends to form a hollow tube. It is also strengthened with ________. These

features allow xylem to transport _________ efficiently.

Phloem tissue is also specialised. Unlike xylem,

phloem is made of _________ cells. It has a

sieve tube to transport food made in

________________ and special companion

cells to control where food is transported to.

Label the diagram to show these features.

Hint:

High water concentration Root hair cells Mesophyll

Low water concentration xylem vessels Moist soil

Celery cross section Xylem Vessels

Phloem Structure

1

3

2

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Gas exchange at the leaves

Stomata allow gas exchange to take place at the leaves. Your teacher will allow

you to look at stomata under a microscope by doing a leaf peel.

Stomata

Stomata are tiny _________ found on the surface of a

leaf. Plants take in __________ __________ from the air

through these stomata.

Unfortunately water vapour is _______ through the

stomata. To overcome the loss of water the stomata

________ at night when the plant is unable to undergo

photosynthesis.

The ________ cells on either side of the stomata are

responsible for opening and closing the pore.

Transpiration (N5)

_______________ is the name of the process by which water is pulled up the

plant stem against the force of gravity!

Water from the walls of the leaf cells lining the moist air spaces

_____________ and is lost by transpiration via the ____________. In order

to replace these losses, cells draw water from the xylem vessels and set up a

transpiration pull.

The rate of transpiration is affected by a number of factors. We can measure

the rate of transpiration using a potometer. A potometer can be used to

measure the volume of water absorbed by a leafy shoot and we can use this to

work out how quickly transpiration occurs.

The rate of transpiration can vary depending on the environment. Factors which

increase the rate of evaporation of water also increase the rate of

transpiration in a plant. Can you unscramble the letters to show four factors

which increase transpiration rate?

_ _ _ _ / _ _ _ _ _ _ _ _ _ _ _ (PREMATURE HEIGHT)

_ _ _ _ / _ _ _ _ _ (END SWIPED)

_ _ _ _ _ _ _ _ (I HUM TIDY)

_ _ _ _ _ _ _ /_ _ _ _ (AREA CAR FUSE)

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Transpiration Investigation:

Write a suitable aim for your investigation.

Choose one of the following independent variables (what we are going

to change in our experiment): wind speed, temperature, humidity OR

surface area.

Label the diagram of a simple potometer

Design an experiment to investigate the effect of your chosen variable

on the rate of transpiration in a leafy shoot.

Write a summary of your method.

Write a conclusion for your investigation.

Extra Challenge Questions for the enthusiast……

Using your knowledge of osmosis, predict what would happen to the guard cells

under the following conditions… (Score out the incorrect words in each pair)

Guard

cells

stoma Guard cells will take in/lose water by osmosis as water will enter/leave

the cell from a high water concentration outside to a lower water

concentration inside the guard cells. Cells will become flaccid/turgid and

the stoma pore will open/close.

Guard cells will take in/lose water by osmosis as water will enter/leave

the cell from a high water concentration inside to a lower water

concentration outside the guard cells. Cells will become flaccid/turgid and

the stoma pore will open/close.

Plant Transport:

12 words about plant transport are hidden in

the word search. Can you find them? Use the

hints below…….

1. Gaseous raw material for photosynthesis

2. Cells which form the stomata

3. Tissue that transports food made in photosynthesis

4. Liquid raw material for photosynthesis

5. Cells which control phloem

6. Strengthens xylem vessels

7. Leaf structure that controls gas exchange

8. Waterproof layer that protects leaves

9. Transparent cells present on upper/lower leaf surfaces

10. Cells that contain chlorophyll (palisade/spongy)

11. Force that pulls water from roots to leaves

12. Hollow tubes that transport water

Potometer

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Topic 2: Animal transport and exchange In the same way that plants need a transport system to move raw materials and

products of photosynthesis, animals need transport systems to ensure raw

materials are delivered to every cell in the body and waste materials are

removed.

Revision:

1. What process inside living cells releases energy from food?

_________________

2. Complete the equation below to show this process:

3. Where does each stage take place in the cell?

Stage 1: ______________ Stage 2: ______________

Enzyme controlled reactions

pyruvate pyruvate

2 ADP + 2 Pi

Stage 1

Stage 2 pyruvate

water

18 ATP

oxygen

Enzyme controlled reactions

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The raw materials for respiration (_________ and ___________) must be

taken into the body and transported to the cells. Waste materials from cells

must also be transported away. This is the reason that mammals have transport

and exchange systems. Use arrows to match the body systems to the correct

functions:

Digestive system

Respiratory system

Circulatory system

We are now going to look at each transport and exchange system

The Circulatory System

The circulatory system in mammals transports blood containing materials such

as nutrients, oxygen and carbon dioxide.

Blood Composition

Blood contains a watery yellow liquid called __________. Blood gets its red

colour from the red blood cells which contain the red pigment

______________. Haemoglobin carries oxygen.

Red Blood Cell Revision: Can you complete the diagram to show the other

features of red blood cells that allow them to be suited to their function

(remember cells are specialised to help them do a particular job)

Takes in oxygen for respiration and removes carbon dioxide (and water)

Transports food which is broken down to release glucose (for respiration) and allows waste to be removed from the body.

Transports materials such as food, oxygen and waste materials throughout the body.

Contain haemoglobin

to carry oxygen

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Blood contains approximately 55% plasma, 1% (white blood cells and platelets)

and 44% red blood cells. Use this information to make a graph below.

Blood Composition

We are now going to look at the blood components in more detail.

Haemoglobin is a protein inside the red blood cells. In locations in the body

where there is a high concentration of oxygen, haemoglobin forms

oxyhaemoglobin.

Location: ____________ Colour of blood: ___________________

Blood with a ______ concentration of oxygen is described as oxygenated.

In locations where the oxygen concentration is low, haemoglobin releases oxygen

Location: ____________ Colour of blood: ___________________

The oxygen then diffuses into the cells. Blood with a _____ oxygen

concentration is described as deoxygenated.

Blood components:

Plasma: yellowish liquid containing

water; transports food, etc.

White blood cells: to fight

disease.

Platelets: to clot blood

Red blood cells: to transport

oxygen

Title

X-axis label

Y-axis label

Units?

Plot

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White blood cells and body defence

White blood cells are part of the immune system and are involved in destroying

pathogens. In S2 you learned about how the body defends itself against

disease.

Revision:

1. What are the three main types of microorganism?

2. What are pathogens?

3. What are the body’s first lines of defence against pathogens?

4. What is the immune system?

5. What are vaccines?

Two main types of white blood cell

In defending the body, there are 2 main types of cells involved:

_____________ which carry out phagocytosis by _________ pathogens

and digesting them (breaking them down).

_____________ which produce antibodies which destroy pathogens.

Antibodies are __________ to particular pathogens.

In the box below, you should draw the two types of white blood cell and

summarise the job that they do to defend the body.

White Blood Cells

Phagocytes Lymphocytes

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The Circulatory System

The blood allows materials to be transported around the body through the

circulatory system. The circulatory system consists of the __________ ,

__________ __________ and the _________ .

The circulatory system has two circuits allowing blood to flow

through the heart twice. One circuit allows oxygenated blood

to be taken to the cells from the lungs (where _________ is

taken in). The second circuit allows deoxygenated blood to be

taken from the cells to the lungs (where _________

_________ is breathed out).

Label the diagram to show the heart, lungs and tissues of the

body. Your teacher may ask you to shade the oxygenated

blood in RED and the deoxygenated blood in BLUE.

NB: this is a very simplified drawing of the heart and

circulation. On the next page your teacher will give you a more

detailed diagram to complete. It shows the pathway of blood

through the heart, lungs and the main organs of the body.

Blood composition activities:

Make model blood

Body defences poster

Diseases and Vaccines activity (newspaper article / patient leaflet, etc.)

White blood cell types poster

Blood donation activities

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Pathway of blood through the heart, lungs and body:

The tubes that transport blood are called _____________. In your diagram

above, there are two types of blood vessels named: ___________ and

_______.

In mammals there are three types of blood vessel:

Arteries – which take blood Away from the heart

Veins – which take blood back IN to the heart

Capillaries – which carry blood through tissues and organs.

Later we will look at the arteries, veins and capillaries in more detail.

In order to move blood through the circulatory system a _______ is needed.

The heart is a ____________ pump. When the muscle contracts, it squeezes

blood up and out of the heart.

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You are now going to look at the structure of the heart (your

teacher may do a dissection of the heart with you!).

The heart has two types of chamber:

Atria – the top chambers of the heart that receive blood.

Ventricles – the bottom chambers of the heart that

squeeze blood upwards and out of the heart.

Label the two atria and the two ventricles. Remember: in

diagrams the parts of the body on the right of the diagram are

always labelled “LEFT” and the parts the left of the diagram are

always labelled “RIGHT”.

You are now ready to look at the structure of the heart and the flow of blood

through it:

__________ side __________ side

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Flow of blood through the heart, lungs and body

Complete the table below to summarise the structure of the heart and its main

blood vessels:

Structure /

Blood vessel

Description

Pulmonary

artery

The pulmonary artery takes deoxygenated blood from the

right ventricle back to the lungs to be oxygenated.

Aorta The aorta takes oxygenated blood from the left ventricle

to the rest of the body.

Right atrium The right atrium contracts and pushes deoxygenated blood

down into the right ventricle.

Left atrium The left atrium contracts and pushes oxygenated blood

down into the left ventricle.

Vena Cava The vena cava takes deoxygenated blood from the rest of

the body into the right atrium.

Pulmonary Vein The pulmonary vein takes oxygenated blood from the lungs

into the left atrium.

Right Ventricle The right ventricle receives blood from the right atrium.

It contracts and pushes deoxygenated blood back towards

the lungs via the pulmonary artery.

Left Ventricle The left ventricle receives blood from the left atrium. It

contracts and pushes oxygenated blood towards the rest

of the body via the aorta.

Valves Valves are found between the atria and ventricles, and

between the ventricles and aorta and pulmonary artery.

They prevent backflow of blood.

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TASK: Imagine you are a red blood cell. Describe the path you would take as

you move through the body. You should start at the lungs (Hint: use the word

bank below to make sure you have described one full circuit!)

Structure of Arteries, Veins and Capillaries

Arteries take blood ________ from the heart at ______

pressure. Because blood inside the arteries is at high

pressure, the structure of arteries must be able to

withstand the force. They have thick muscular walls and

narrow lumen

Veins take blood ______ ___ the heart. Blood in veins is

under ________ pressure than the blood in the arteries

so they have special ________ which prevent blood from

flowing backwards. They have _________ walls and wide

_______.

Capillaries are the finest vessels of the circulation and

connect arteries to veins. They have ______ walls which

are one cell thick. This allows materials to diffuse quickly

in and out of the blood and body tissues. Capillaries also

form large networks to ensure that all cells receive a blood

supply (capillary networks give a large surface area for the

movement of materials).

left atrium right atrium left ventricle right ventricle

aorta pulmonary vein lungs pulmonary artery

vena cava “drop off oxygen” body tissues “pick up oxygen”

One cell thick

Thick wall,

narrow lumen

Thinner wall,

Wider lumen

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Capillary network

Why must the blood leaving the body tissues be taken back to the heart?

___________________________________________________________

___________________________________________________________

___________________________________________________________

___________________________________________________________

Use your notes to complete the summary table below. The capillaries have been

completed for you:

Type of blood

vessel

Wall

thickness

Internal

diameter

(lumen)

Valves Blood

pressure Function

Arteries

Capillaries

One cell

thick

Very

narrow

but wide

enough for

blood cells

to squeeze

through

No valves - Capillaries carry blood through

tissues and organs. They allow

materials exchanged between

blood and cells by diffusion.

Veins

Arteries branch forming finer and finer vessels until the capillary network. Here, the

capillary walls are only one cell thick. Oxygen (and nutrients) leave the blood capillary and

diffuse into the body cells from a _____ concentration to a _______ concentration. At

the same time, carbon dioxide (and waste) leave the body cells by diffusion. The capillaries

join together to form wider vessels which carry the blood back to the heart via the veins.

Oxygenated blood blood

Deoxygenated blood

Capillaries

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Think, Pair, Share:

What are the raw materials needed for respiration?

For each raw material, what organ system allows the material to be absorbed

into the bloodstream?

What features do these organ systems have that allow lots of the material to

be absorbed into the bloodstream?

Consolidate:

Your teacher will help you summarise the class discussion. Write this below:

Coronary Arteries

One of the first arteries to branch off

from the aorta is the _____________

artery. This supplies the heart muscle

itself with blood. Blockage of the coronary

arteries prevents the flow of blood to the

heart muscle. When this happens part of

the heart muscle is deprived of oxygen,

causing the tissue die. This results in a

heart attack. Label the

diagram to show:

aorta, left coronary artery right coronary artery.

Absorption of materials

The raw materials needed for respiration must be absorbed into the

bloodstream so that they can be delivered to the cells.

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Topic 3: Absorption of Materials

Absorption in the Lungs

The lungs are large organs where gas

exchange occurs.

Air passes through the _______

and _______, down the _______, enters

into each lung via the _______ which

branches into tiny _____________.

Each bronchiole ends at an _______

(air sac) where gas exchange occurs.

Special features of the lungs (background information)

The lung has some specialised features that allow breathing to function

effectively.

The trachea and bronchi have __________ ____ to keep

the airways open. Cartilage is a _________ but

__________ tissue that allows air to flow into the lungs

unobstructed.

The trachea and bronchi are lined with tiny hair-like

___________ and cells that secrete _________.

Rhythmic beating of cilia sweeps mucus containing trapped

_______ and _________-___________ upwards and

away from the lungs.

Gross facts for the day!!!!!

The average adult produces about 1 to 1.5 litres of mucus a day - enough to fill

a kettle!

Mucus is made from water, proteins, antibodies and salts.

Colour clues: clear mucus: clear of infection

white mucus: sign of congestion

yellow mucus: signals a cold

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Gas Exchange at alveoli

Blood arriving at the lungs is said to be

DEOXYGENATED because it contains a

_____ _______________ of oxygen (high

concentration of carbon dioxide).

Diffusion of oxygen from the alveoli to the red

blood cells occurs (carbon dioxide diffuses from the

plasma into the alveolus). Blood therefore becomes

OXYGENATED as it contains a _______

________________ of oxygen (lower concentration

of carbon dioxide).

The alveoli are well suited to gas exchange because of

their specialised structure. Complete the summary

table below to show these features:

Feature Function

Large surface

area

Allows oxygen to dissolve easily.

Thin lining (only

1 cell thick)

Rapid pick up of oxygen by red blood cells for respiration

rapid removal of Carbon Dioxide.

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Lung Facts! (TWIG)

Your lungs have about the same volume as a football, and around 300 million

tiny air chambers each on average.

If you laid all of them out on the ground they would cover a badminton court.

Each human lung holds about 3l of air.

A blue whale's lung can hold 2500l of air.

Every day you breathe in and out around 25,000 times.

The average human can hold their breath for up to 60 seconds, but some have

trained themselves to hold their breath for over 20 minutes!

Some divers train themselves to dive for long periods of time

without oxygen

Gas Exchange at alveoli

Oxygen:

At the lungs there is a higher / lower oxygen concentration in the inhaled air

than in the blood entering the alveolus. Oxygen diffuses from the inhaled air

into the blood from a high oxygen concentration to a low concentration. The

oxygen binds to haemoglobin in the red blood cells to form ________________

Carbon dioxide:

At the lungs there is a higher / lower carbon dioxide concentration in the

inhaled air than in the blood entering the alveolus. Carbon dioxide diffuses from

the blood to the air sacs from a high oxygen concentration to a low

concentration.

Project:

Your teacher may give you some information on smoking and the

effects that it can have on the lungs and overall heath. Use your

knowledge of the lung structures to produce a poster or health

information leaflet about smoking and health.

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Absorption in the Small Intestine

The mammalian digestive system allows large insoluble food to be broken down

into smaller soluble materials. Each of the structure of the digestive system are

well suited to this function.

Enzymes are vital in digestion as they allow large insoluble food to be broken

down into smaller soluble materials….

1. What is the definition of an enzyme?

_______________________________________________________

_______________________________________________________

2. Write down the general equation for an enzyme reaction:

3. All digestive enzymes take big molecules and make them into smaller

molecules. What type of reactions are these? ____________________

The Small Intestine (background information)

This is a long narrow section of the gut which gives a large surface area for the

absorption of food. The function of the small intestine is to __________ the

products of digestion through the wall of the gut and into the

______________.

As partially digested food is moved along the small intestine by peristalsis,

three digestive enzymes from the pancreas continue to breakdown the

remaining _________ ____________ molecules. This prepares the food

molecules for their ______________through the lining of the small intestine.

Revision:

Write the word equation for all enzyme reactions

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The role of Villi

The internal structure of a villus allows

them to be ideally suited for the

absorption and transport of digested

food.

Villus features:

Thin lining:

_________________________

_________________________

_________________________

Blood capillary:

_________________________

_________________________

_________________________

Central Lacteal:

_________________________

_________________________

_________________________

The small intestine is very efficient at its job because of its ___________ .

The small intestine has a _________ ____________ _________. This is due

to it being very long and also having a ________ inner surface. The inner

surface is also covered in tiny finger-like projections called _______.

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Absorption of Materials Summary

Now that you have learned the features of the lungs and the digestive system

you should be able to summarise the features that they have in common.

Write notes on the shared features of the lungs and the digestive tract and

describe how these features allow efficient absorption of materials:

27

Topic 4: Control and Communication The maintenance of a constant internal environment by the body is called

_________________. Factors that are kept at a set point include:

• ____________________________

• ____________________________

• ____________________________

Thermoregulation is the regulation of body temperature so that it stays at

a set point of ___°C.

• If the body temperature falls ____ _____ then biological

reactions may happen too _______ for cells to survive.

• If the body temperature rises ____________

then _________ and other cell ___________

may be damaged.

The Brain and the Hypothalamus

•

• The _________________ in the brain

contains the temperature monitoring

centre for the body.

• The hypothalamus receives _______

__________ from structures in the skin

called __________________, which

give information about the surface

temperature of the body. The

hypothalamus also contains its own

thermo-receptors, which are sensitive to

the temperature of the __________.

The hypothalamus responds to the information it gets from thermo-receptors

by sending nerve impulses to __________, such as the skin, to return the body

temperature back to ___________.

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The response of the body to changes in temperature

Too hot

Too cold

All of the methods to regulate body temperature mentioned so far are

___________________________ - we do not consciously decide to sweat or

to shiver.

In contrast, humans are also able to make___________________________,

for example when we decide to take action to help regulate our body

temperature.

Water balance

For the cells of our body to work properly, it is important that their water

content is maintained at the correct level. This means our body must maintain a

__________ between the water we take in (by drinking and eating) and the

water we lose (through sweating, excretion and breathing out) .

Water balanced is maintained by

the _________. Kidneys control

blood water concentration through

the action of a _________ called ADH.

We are now going to look at some examples

of hormones of the human body.

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Hormones

Hormones are __________ _____________ that travel around the body in

the ___________.

Hormones are __________ _____________. Hormones are released into the

bloodstream by groups of cells called __________ ________. Hormones are

transported in the ________ __________ to target body tissues where they

bind to cells to produce a response.

Each hormone stimulates a __________ response in either individual cells,

tissues or in other glands. The cell that a hormone acts on is called its

________ _____.

• A specific hormone can only affect cells if the cells have a _________

for it.

• The diagram below shows two cells targeted by two different hormones.

• Hormone one cannot affect the cell on the right because the cell does not

have a receptor for it.

30

The __________ system co-ordinates the hormones that are produced in the

body. The endocrine system consists of many ________ which release

hormones directly into the bloodstream.

The Endocrine System

Hormonal control of glucose

The concentration of glucose in the blood must be kept at a ____ ________.

• If the blood glucose concentration rises ____ ______, then the water

concentration of the blood will fall and water will diffuse out of cells by

osmosis. This may interfere with cell reactions.

• If the blood glucose concentration ____ ____ _____, then body cells will

not receive as much glucose and so will not be able to release as much

energy in respiration.

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• The concentration of glucose in the blood is regulated by the action of the

hormones _______ and __________.

• The target cells of these hormones are found in the liver. The liver stores

the body’s glucose in the form of___________ . Glycogen can be broken

down again and the glucose released into the blood when it is needed.

Under what circumstances do you think blood glucose levels will rise?

___________________________________________________________

Under what circumstances do you think blood glucose levels will fall?

___________________________________________________________

Complete the table to show what happens when blood glucose changes from its

set point.

Glucose

level

Hormone

released

Response Effect

Increased

lowers blood

glucose to

normal

Decreased

raises blood

glucose to

normal

32

The terms involved in hormonal control of glucose sound very similar and can be easily

confused. Your teacher may give you some hints to help remember which is which…..

The organ in the above diagram is called the pancreas. It has special receptor

cells that detect rises and falls in blood glucose concentration. If the glucose is

too low, the pancreas releases less insulin and more glucagon. This brings the

blood glucose level back to the set point. If the glucose is too high, the

pancreas releases more insulin and less glucagon. This brings the blood glucose

level back to the set point.

33

Additional information

Diabetes

________________ is the body’s _______________ to control its blood

__________________ levels.

After eating, ______________ glucose levels increase much ______________

and take much _______________ to come back normal than someone without

diabetes.

Research investigation – type 1 and type 2 diabetes

Cause

Risk factors

Symptoms

Treatment

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Control and Communication: The Nervous System

Nervous system

Cells ___________________ with each other through a nervous system. The

human nervous system is made up of the ____________ nervous system (CNS)

and _________________.

The CNS is made up of the ______________ and the ______________ cord.

The brain

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Neurons

The brain is connected to the rest of the body by nerves, made up of cells called

________________. There are ____ types of neurons.

1. ______________ – carries information from receptors to _________

2. ______________ – carries information from CNS to _____________

3. ______________ – connects sensory and ________________ neurons

Synapses

______________ impulses carry messages along neurons. Neurons have

_____________ between them called ___________________.

__________________ transfer the message across _______________.

This allows signals to be passed along a _____________ of neurons.

36

Summarise the steps involved in synaptic transmission. Use the numbers in the

diagram to help.

Now we are going to look at protective reflexes. Can you think of any

examples of reflex actions that help to protect your body from harm?

1

2

3

37

Experiment

Aim: to see how quickly we can respond to catch a falling ruler.

Results:

Attempt Catch distance (cm)

1

2

3

4

Conclusion:

My eyes contain ______________ which detect the _______________ of

light. They sent impulses to my brain along ______________ neurons. My brain

then sent impulses via relay ______________ to ______________ neurons to

reach _________________ which were my finger __________________,

making me carry out the ______________ of catching the ruler.

Reflex reactions

A ___________ reaction is a rapid _________________ response. It is

quicker as the impulse is only carried to the _____________ cord, not the

____________. It protects the body against _____________, e.g. knee jerk,

burning finger, _______________. The arrangement of the 3 different neurons

is called a _____________ _____.

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MULTICELLULAR ORGANISMS - I wan’na be like you

WORDBANK

Word Definition Photosynthesis

Upper epidermis

Palisade

Mesophyll

Spongy

Mesophyll

Vein

Lower epidermis

Guard cells

Stomata

Xylem

Lignin

Phloem

Root Hair cells

Potometer

Transpiration

Left atrium

Right atrium

Left ventricle

Right ventricle

Aorta

Vena Cava

Pulmonary artery

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Pulmonary vein

Coronary Artery

Red blood cells

Haemoglobin

Oxyhaemoglobin

Veins

Arteries

Capillaries

Trachea

Bronchus

Bronchiole

Alveoli

Small intestine

Villus

Lacteal

Glucose

Amino acids

Homeostasis

Endocrine

Gland

Hormone

Target tissue

Receptor protein

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Diabetes

Pancreas

Insulin

Glucose

Glycogen

Glucagon

Liver

Nervous System

CNS

Cerebrum

Cerebellum

Medulla

Neuron

Sensory Neuron

Inter Neuron

Motor Neuron

Receptor

Stimulus

Response

Effector organ

Electrical

impulse

Synapse

Chemical signal

Reflex arc

41