Describe the structure of viruses.

fungi

bacteria

viruses

Viruses are true parasites living off the cell they have infected.

Some viruses enter a host and leave virtually unnoticed.

Others cause disease and destroy the host.

They are the tiniest and simplest of microbes.

They can be 10,000 times smaller than bacteria.

Viruses consist of a small collection of genetic material (DNA or RNA) covered in a protective protein coat called a capsid.

Once inside a cell the virus takes over.

The virus gives the host cell instructions.

In other words the host cell does all the work and the virus gets all the rewards.

They persuade the host cell to make new viral particles.

The same virus can cause different reactions in different hosts.

For example, flu viruses infect birds, pigs and humans.While some of these flu viruses will not harm the birds

they can overwhelm and kill humans.

protein coat

nucleic acid

I can describe can describe the structure of viruses.

Give an outline of the stages of viral replication.

Genetic material (DNA)

Protein coat

Hollow tail

Fibre

Host Cell

Virus attaches to host cell

Virus attaches to host cell

Virus attaches to host cell

Virus attaches to host cell

Virus attaches to host cell

Virus puts tail through cell wall

Virus puts tail through cell wall

Virus pierces through cell wall

Virus pierces through cell wall

Virus pierces through cell wall

Virus pierces through cell wall

Viral DNA injected into host cell

Virus pierces through cell wall

Viral DNA injected into host cellVirus pierces through cell wall

Viral DNA injected into host cellVirus pierces through cell wall

Viral DNA replicates

Protein coats are synthesised

Each viral DNA becomes enclosed in a protein coat

Each viral DNA becomes enclosed in a protein coat

Each viral DNA becomes enclosed in a protein coat

Host cell bursts releasing many copies of virus

Host cell bursts releasing many copies of virus

Attachment

Insertion

Replication

Release

Remember AIRR

I can give an outline of the stages of viral replication.

Give examples of viral infections and how they are spread.

Complete the

viruses group

activity to find

out about viral

diseases and

how they are

spread.Complete the table in your booklet

I can give example of viral diseases and how the are spread.

Name the different parts of the blood and their function.

The blood is extremely important for the body.

It carries substances to all parts of the body through the circulatory system.

On average a person has 5 litres of blood.

PlasmaPlasma

Red Blood CellsRed Blood Cells

White Blood CellsWhite Blood Cells

PlateletsPlatelets

Blood may look like just a red liquid, however, it is made up of a variety of different types of cells all suspended in a fluid.

The main component of blood is a fluid called plasma which is mainly water.

Suspended in the plasma are: red blood cells and white

blood cells.

dissolved substances such as glucose, urea and amino acids

plasma proteins such as antibodies and hormones

There are around 5 million red blood cells per mm3 of blood.

Their main function is to carry oxygen.

Red blood cells have a biconcave shape.

This increases their surface area.

They contain a substance called haemoglobinhaemoglobin, a red oxygen carrying pigment which gives red blood cells their colour.

Red blood cells are very special animal cells because they do notdo not contain a nucleus.

This means they have a maximum amount of space for haemoglobin.

Oxygen is carried in red blood cells.

It is attached to a haemoglobin, the red pigment found in rbc.

The oxygen is carried around the body attached to haemoglobin, it can then leave the rbc and diffuse into the body cells.

haemoglobin + oxygen —> oxy-haemoglobin

There are many different types of white blood cell.

They are larger than red blood cells and do contain a nucleus but no haemoglobin.

White blood cells are involved in the immune system.

Platelets are tiny cells found in the blood

They have no nucleus and their job is to make the blood clot.

If a blood vessel is damages platelets rush to the area and form a clump to help stop blood loss.

I can name the different parts of the blood and their function.

Name and recognise the two main types of white blood cell involved in defence.

Describe the process of phagocytosis, as used by white blood cells, stating the importance of lysosomes in this process.

Before disease causing organisms can get into the body and cause harm, they must pass several barriers.

First-line defences are features of the body that help to prevent the entry of harmful organisms.

SKIN TEARS

HAIR & MUCUS

White blood cells are the second-line defence.

A macrophage is a special type of white blood cell which can engulf and digest bacteria.

It has a nucleus and special structures called lysosomes which contain digestive enzymes.

Engulf

DigestDestroy

Finding

lysosome

Bacterium being engulfed

Bacterium trapped inside vacuole

Lysosome release digestive enzymes into

vacuole

The enzymes digest the bacterium so it is now

harmless

I can name and recognise the two main types of white blood cell involved in defence.

I can describe the process of phagocytosis, as used by white blood cells, stating the importance of lysosomes in this process.

Explain the role of antibody production in immunity.

Macrophages are a type of non-specific immunity.

This is because they work against lots of different pathogens.

Specific immunity involves acting against one particular pathogen.

A specific immune response is against one particular type of virus.

The white blood cells involved are called LYMPHOCYTES.LYMPHOCYTES.

These produce special protein molecules called ANTIBODIESANTIBODIES.

If a child catches the chicken pox virus, a specific lymphocyte is stimulated.

This lymphocyte then multiplies.

All these lymphocytes produce antibodies specifically against the virus.

The virus is then destroyed eventually.

antigen

cell

Antigens are your body’s way of telling which cells are your own, and which

cells are unwanted invaders.

Pathogens e.g. bacteria or viruses, have different

shaped antigens from your body cells, and your body

can tell that they don’t belong.

Antigens

red blood cell

SalmonellaI cause food poisoning

Lymphocyte recognises

antigen as non-self

Lymphocyte produces antibodies

specific to the antigen

Antibodies specifically attack

the antigen

The bacteria or virus is

rendered harmless

Antibodies attach to the viral antigens at receptor

sites. This causes the virus to become harmless.

Antibody production is a type of specific immunity.

This is because the antibodies being produced only work against one type of antigen.

1. _______enters body cell.

1. Viral particles become attached to ____________ by their antigens.

2. Lymphocytes multiply and produce large numbers of ____________.

3. ___________ and antibodies meet and combine. This makes the antigen ___________.

2. Virus ___________.

Antigens antibodies multiplies Virus lymphocyte harmless

New pathogens you have never been exposed to before attack the body and multiply. This makes you feel ill

Lymphocytes detect the foreign antigens on the pathogens

Lymphocytes make specific antibodies for the antigen

The antibodies attach themselves to the antigens on the pathogens and make them harmless

Lymphocyte remembers the shape of the antigen

Pathogen you have previously come into contact with enters your body again

Lymphocytes instantly recognise the pathogens and make antibodies immediately

The antibodies attach themselves to the pathogens and kill them before the pathogens have a chance to make you ill. You now have immunity!!!

Make a model - The Immune Response

Collect: 10 cocktail sticks 3 pipe cleaners 2 colours of playdoh You have 10 minutes to design and make a model showing the immune response after exposure to a pathogen Remember to include: pathogen antigen antibody phagocyte

Key part Part of structure

Explanation of what it is/ does?

Pathogen A disease causing microbe

Antigen Found on the outside of the pathogen

Antibody Is made by the white blood cells to kill the pathogen

Phagocyte A type of white blood which engulfs and ingests the pathogens

What was good about your model?How do you think it could have been improved?

Phagocyte

Antibody

Antigen

Pathogen

I can explain the role of antibody production in immunity.

Explain the importance of knowing blood groups in organ donation.

A

B

AB

O

It is the type of antigens on the

surface of your red blood cells which decide your blood

group.You will have the

opposite antibodies in your plasma

If you belong to the blood group A, you have A antigens on the surface of your red blood cells.

You have B antibodies in your blood plasma.

If you belong to the blood group B, you have B antigens on the surface of your red blood cells.

You have A antibodies in your blood plasma.

You have both A and B antigens on the surface of your red blood cells.

No A or B antibodies at all in your blood plasma.

You have neither A or B antigens on the surface of your red blood cells.

You have both A and B antibodies in your blood plasma.

RECIPIENT’S BLOOD GROUP

O A B AB

DONOR’S BLOOD GROUP

O

A

B

AB

RECIPIENT’S BLOOD GROUP

OAnti-A & Anti-B

AAnti-B

 

BAnti-A

ABNo

antibodies

DONOR BLOOD GROUP

O No antigens

AAntigen A

BAntigen B

ABAntigens

A& B

√ √ √ √

√

√ √

√

√

1. Who is the ‘universal donor’?

2. Who is the ‘universal recipient’?

I can explain the importance of knowing blood groups in organ donation.

A small pool of blood and a knife were found near the bins. After examining the area, the police discovered a body and

identified him as Earnest “One Eyed” Earl.

The police have collected blood samples from the pool of blood

and the weapon. The police need to know their blood types to see if it matches one of the 3 suspects they have identified or if it belongs to the victim.

Carry out the blood typing experiment to see if you can identify who the blood on the weapon and at the crime scene belong to:

Can you find Earl’s murderer?

2. “Slim” Jim Snoot1. Bobby “Baby” Brooks 3. Barbie “Doll” Jones

+ X

X ++ +

X X

Blood Samples Blood group

Suspect 1 A

Suspect 2 B

Suspect 3 AB

Victim O

Crime Scene A

Weapon O

The blood on the weapon must have belonged to the victim.

But the blood left at the crime scene belongs to suspect 1 so he must have

killed Earl!