B4.1 The blood AQA GCSE Biology B4 Organising Animals and Plants . Kerboodle answer : Page No. 53​

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1. Blood carries oxygen, carbon dioxide, nutrients, waste, heat and hormones throughout the body to each of its cells. Without blood, cells would fail to perform as needed to sustain life. Red blood cells are responsible for blood clotting, ensuring that most cuts do not cause major blood loss. White blood cells fight off infection and are a major component of the body’s immune system.
2. a. Blood actually is connective tissue, which is how it is better described.

It composes of plasma, leukocytes (white blood cells), and erythrocytes (red blood cells), and it is these blood cells, which, bein non-liquid, make blood not a liquid really.

1. Haemoglobin
2. 1. Transportation of blood and many other substances such as- waste carbon dioxide produced by the cells is carried to the lungs.
3. Urea formed in your liver from the breakdown of excess proteins is carried to your kidneys where it is removed from your blood to form urine.
4. The small, soluble products of digestion pass into the plasma from your small intestine and are transported to the individual cells.
5. Blood contains White blood cells which include-

Lymphocytes – form antibodies against microorganisms.

Phagocytes – engulf and digest invading bacteria and viruses.

Antitoxins against poisons made by microorganisms.

Blood participates in innate immunity.

Small fragments of complement proteins also adhere to the pathogen surface, flagging them for destruction by phagocytes.

B4.2 The blood cells AQA GCSE Biology B4 Organising Animals and Plants . Kerboodle answer: Page No. 55​

1. a. They carry blood away from your heart to the organs of your body.

This blood is bright-red oxygenated blood.

Structure-Arteries have thick walls containing muscle and elastic fibres.

1. They carry blood away from the organs towards your heart.

This blood is usually low in oxygen and therefore a deep purple-red color.

Structure-They have much thinner walls than arteries and often have valves to prevent the back flow of blood.

1. They form a huge network of tiny vessels linking the arteries and the veins. Capillaries are narrow with very thin walls
2. a. Arteries carry oxygenated blood from lungs to various body parts. From there capillaries connected to them which carry blood to the tissue and again from tissue to the veins. Veins then take blood back to heart ehich is deoxygenated.
3. Capillaries have very thin walls , they are attached to arteries as well as to the veins and carry out diffusion of oxygenated blood from artery to tissue and deoxygenated blood from tissue to vein.
4. Blood flow rate and blood pressure falls when blood leaves a fish’s gills.

The low blood pressure in the single circulatory systems present in fish is fine for fish but would be insufficient for efficient kidney function in mammals.

B4.3 The heart AQA GCSE Biology B4 Organising Animals and Plants . Kerboodle answer: Page No. 57​

2. a. Heart valves are present on the injunctions of atrium and ventricle.They prevent back flow of blood from the ventricles back to atrium and vice versa. The sound of heart beat is the sound of opening and closing of the valves.
3. Coronary arteries – that supply blood to the heart muscle. They supply oxygenated blood to the heart muscles that make them to contact regularly.A clot in coronary artery can cause heart attack.
4. The muscle wall of the left ventricle is thicker than the wall of the right ventricle.This allows the left ventricle to develop the pressure needed to force the blood through the arterial system all over your body. The blood leaving the right ventricle moves through the pulmonary arteries to your lungs.
5. Pulmonary arteries carry blood from the heart to lungs that is deoxygenated that is without oxygen. It is an exception to the general nature of arteries to carry oxygenated blood. In lungs the heart get oxygenated and carried to heart.
6. a. 

Stent-  It is a metal mesh that is placed in the artery.

A tiny balloon is inflated to open up the blood vessel and the stent at the same time. The balloon is deflated and removed but the stent remains in place, holding the blood vessel open.
Stents can be used to open up a blocked artery .

Some types of stents also release drugs to prevent the blood clotting.

B4.4 Helping the Heart AQA GCSE Biology B4Organising Animals and Plants . Kerboodle answer : Page No. 59​

1. Pacemaker – It is controlled by a group of cells found in the right atrium of your heart that acts as your natural pacemaker .
2. The artificial pacemaker sends strong, regular electrical signals to your heart that stimulate it to beat properly.

Modern pacemakers are very sensitive to what your body needs and only work when the natural rhythm goes wrong. 

3. a. Heart valves remain under pressure. They may start to leak or become stiff and not open fully, making the heart less efficient. Faulty heart valves can be replaced by surgery. When there is a backflow of blood from the arteries back to the heart which results in complete disruption of circulation system.

b i. a. Biological valves do not require taking medicines throughout life. But they remain working only for 10-12 years.

1. a. They are mechanical valves which replaced are functional for life. Person have to take medicines throughout the life.
2. AGAINST:

The therapy is too expensive.

The device should go back to the lab and not be used in humans until it can be reconstructed of materials less offensive to human blood.

The device should only be used in humans as a temporary “bridge” to transplantation.

The money would be better spent exploring ways to prevent heart disease.

The research should not be done by a private institution like Human, where the profit motive might conflict with scientific objectivity.

IN FAVOR:

About 30,000 people a year who are either ineligible for human heart transplant or for whom no human heart can be found die of heart disease.

Recurrent failure has been the norm in early stages of emerging medical techniques, such as heart transplantation and kidney dialysis.

Questions about the future cost to society versus the public good cannot be answered until clinical trials have determined whether the device can work.

Federal regulation, peer review and public scrutiny are too thorough to permit a private institution to distort research in the interest of profit.

A patient’s consent may be granted under the duress of impending death, but no one has the right to usurp that choice.

B4.5 Breathing and gas exchange AQA GCSE Biology B4Organising Animals and Plants . Kerboodle answer: Page No. 61​

. Breathing in, oxygen-rich air moves into your lungs. This maintains a steep concentration gradient with the blood. As a result, oxygen continually diffuses into your bloodstream through the gas exchange surfaces of your alveoli.

Breathing out removes carbon dioxide-rich air from the lungs. This maintains a concentration gradient so carbon dioxide can continually diffuse out of the bloodstream into the air in the lungs.

2. a. Exchange of gases between body and environment by lungs is called gaseous exchange.
3. To perform day to day activities we need energy that is produced by the cells by utilizing glucose which needs oxygen.

Gaseous exchange is important because it provide energy by respiration.

3. The carbon dioxide breathed out is a by-product of the process of cell respiration, as is water. In this process, energy is produced in the mitochondria of cells. Both oxygen and glucose are required for this. Glucose contains carbon. That’s where the carbon in carbon dioxide comes from. Glucose plus oxygen produces carbon dioxide, water and energy. When this process stops, the cell dies. Carbon comes out from food we eat.
4. Adaptations of alveoli

Surface area – They are made up of clusters of alveoli that provide a very large surface area. This is important for achieving the most effective diffusion of oxygen and carbon dioxide.

Capillaries – The alveoli also have a rich supply of blood capillaries. This maintains a concentration gradient in both directions.

Concentration gradient – The blood coming to the lungs is always relatively low in oxygen and high in carbon dioxide compared to the inhaled air. This makes the exchange rapid and effective.

B4.6 Tissues and organs in plants AQA GCSE Biology B4 Organising Animals and Plants . Kerboodle answer: Page No. 63​

1. a. It cover the surfaces and protect them.

These cells secrete a waxy substance that waterproofs the surface of the leaf.

Spongy mesophyll tissue-

It has big air spaces and a large surface area to make the diffusion of gases easier.

1. It  tissue contains lots of chloroplasts, which carry out photosynthesis.
2. It has big air spaces and a large surface area to make the diffusion of gases easier.
3. In order for leaves to obtain water and minerals from the roots and for food manufactured in mature leaves to be transported to the roots and other non photosynthetic regions, each leaf must be connected to the overall vascular structure of the plant.

The main vascular bundle of xylem and phloem present in the stem of a plant bifurcates into leaf traces, which are branches of vascular tissue that supply leaves.

Each leaf trace further branches into the familiar veinsthat can often be seen along the surface of leaves, and the veins repeatedly subdivide as well.

The vascular components, which serve as a basic skeletal structure in addition to functioning in the transport of materials, extend throughout the mesophyllso that the xylem and phloem are brought into propinquity with leaf tissues that carry out photosynthesis.

B4.7 Transport system in plants AQA GCSE Biology B4Organising Animals and Plants . Kerboodle answer: Page No. 65​

1. Plants need transport system for transport of food and water and mineral ions which are required for daily processes.
2. Xylem transport the water and minerals while Phloem transport food and nutrients

The movements in Xylem is unidirectional from roots to aerial parts while the movements in Phloem are bidirectional.

Xylem tissues has star shape while phloem is not star shaped.

Phloem occurs on the outer side of the vascular bundle while xylem is at the centre of the vascular bundle.

3. Bark contain phloem which have a great function in maintaining the plant. It  transports the sugars made by photosynthesis from the leaves to the rest of the plant.

Transported to-1 Growing part   2. For storage also. Phloem is a living tissue – the phloem cells are alive.

Translocation –The movement of dissolved sugars from the leaves to the rest of the plant is called translocation. Phloem is found underneath the bark. If the bark of a plant is eaten the transportation by phloem stops and plant dies.

4. 250+ 280+ 265+245+270+255+290/7=265.

B4.8 Evaporation and transpiration AQA GCSE Biology B4 Organising Animals and Plants . Kerboodle answer: Page No. 67​

1. a. Small openings all over the leaf surface are known as stomata.
2. The stomata can be opened when the plant needs to allow air into the leaves. Carbon dioxide from the atmosphere diffuses into the air spaces and then into the cells down a concentration gradient. At the same time, oxygen produced by photosynthesis is removed from the leaf by diffusion into the surrounding air.
3. When the stomata open, plants lose water vapour through them .The

water vapour evaporates from the cells lining the air spaces and then passes out of the leaf through the stomata by diffusion. This loss or water vapour is known as transpiration.

3. This constant movement of water molecules through the xylem from the roots to the leaves is known as the transpiration stream.

When water evaporates from the surface of the leaves, more water is pulled up through the xylem to take its place.

It is driven by the evaporation.

B4.9 Factors affecting transpiration AQA GCSE Biology B4 Organising Animals and Plants . Kerboodle answer : Page No. 69​

1. a. Waxy covering- Leaves have a waxy, waterproof layer to prevent uncontrolled water loss. In very hot environments, the cuticle may be very thick and shiny.

Position of Stomata- Most of the stomata are found on the underside of the leaves. This protects them from the direct light and energy of the Sun.

1. Amount of air movement – In windy conditions or by the blow of fan both increase the rate of evaporation and also maintain a steep concentration gradient from the inside of the leaf to the outside by removing water vapour as it diffuses out.
2. a. Transpiration is not effected so much.
3. Transpiration will be affected as the petroleum jelly, block the stomata so less water vapour will escape and therefore reduce the rate of transpiration.
4. Because we have stomata on the lower  side of the leaf. By applying jelly on lower side which blocks the stomata .Hence no loss of water is there.
5. We know that the leaves of water lilies float. Hence, if the leaves of water lilies would have stomata on their lower side, then they would have been pressed against the water surface. As a result, the stomata would not be able to take in carbon dioxide from air. Thus, the leaves of water lilies have stomata on their upper side, where they easily get air and usually do not come in contact with water.
6. Because there is a lot of water below it and there is no fear of loss of water more in transpiration than taking up by the roots of the plant. There is a plenty of water present.

Summary questions AQA GCSE Biology B4 Organising Animals and Plants . Kerboodle answer: Page No 70​

1. a In this problem there is overfilling of the heart in which not enough blood pumped out of heart into circulatory system, so patient will suffer symptoms of oxygen deficiency because heart never empties properly.It will not pump as efficiently as it will overfill with blood.

1. b)In this problem there is a gap in centre of heart allows oxygenated blood on left side to mix with deoxygenated blood on right side

Blood pumped around body is therefore not fully oxygenated

So baby will suffer symptoms of oxygen deficiency like blue color.

2. Coronary arteries supply oxygen needed by heart muscle to beat and pump blood around body.

If coronary artery is narrowed or blocked, not enough oxygen reaches heart muscle so heart cannot contract properly or may die.

This is particularly noticeable during exercise when heart needs more oxygen to beat harder and faster.

If heart cannot pump properly, body is starved of oxygen.

2. a. If athlete gives blood before the race the athlete will have fewer red blood cells than normal reducing capacity to carry oxygen in blood to supply muscles athlete likely to perform poorly and develop much bigger oxygen debt than usual.

2 b)Here the person will not be able to produce hemoglobin red pigment found in red blood cells that carries oxygen around body person may become anaemic (lacking in red blood cells) and tired and weak because blood cannot carry enough oxygen.

3

a Stent- 

It is a metal mesh that is placed in the artery.

A tiny balloon is inflated to open up the blood vessel and the stent at the same time.

The balloon is deflated and removed but the stent remains in place, holding the blood vessel open.
Stents can be used to open up a blocked artery .

Some types of stents also release drugs to prevent the blood clotting.

1. Percentage of patients dying or suffering heart attack substantially lower after stents fitted than after bypass surgery.

No patients had strokes after stents fitted while more than 2% of patients had strokes after bypass surgery.

Stents seem most successful based on evidence provided.

Practice Questions AQA GCSE Biology B4 Organising Animals and Plants . Kerboodle answer : Page No 71​

01.1. 

01.2. It helps to prevent blood flowing backwards / the wrong way.

01.3. In coronary heart disease the coronary arteries that supply blood to the heart muscle become narrow.

In coronary heart disease the coronary arteries that supply blood to the heart muscle become narrow.

Cause- buildup of fatty material on the lining of the vessels.

Complications-When the blood flow through the coronary arteries is reduced, the supply of oxygen to the heart muscle is also reduced which cause heart attack.

01.4. Statins –

Doctors prescribe statins to anyone at risk from cardiovascular disease.

They reduce blood cholesterol levels and this slows down the rate at which fatty material is deposited in the coronary arteries.

02.1.

A = platelet(s)

B = red blood cell(s)

C = white blood cell(s)

02.2 They contain haemoglobin which can carry oxygen.

They do not have a nucleus which increases the carrying capacity.

large surface area: volume ratio.

03.1. Transpiration.

The student measured the mass of the plant and pot at the end of each day for five days.
His results are shown in Table 1.

03.2. Day 3 -The conditions were hottest and driest.

03.3. 5.2 g / day.

Marram grass grows on sand dunes where the conditions are dry and windy. The leaves are adapted to reduce the rate of water loss.
Figure 4 shows a cross section of a marram cirass leaf.

03.4. Waxy cuticle forms a waterproof layer to trap water.

Leaf is rolled so stomata are less exposed to heat / wind.
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This page contains the detailed and easy notes for AQA GCSE Biology Cell Biology for revision and understanding Cell Biology.

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AQA GCSE Paper 1: Complete Revision Summary

ORGANISATION

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4.2 Organisation

• Organisation hierarchy
• Human Digestive System
• Circulatory System
• Heart and the blood vessels
• Blood
• Coronory Heart Disease
• Non Communicable Disease
• Respiratory System
• Plant Tissues
• Plant Organ System
• Transpiration

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LIVING SYSTEM HIEARARCHY

CELLS

• Nerve Cell
• Muscle Cell

TISSUES

• Muscular tissue
• Epithelial tissue
• Glandular tissue

ORGANS

• Stomach, kidney, liver, pancreas, Heart

ORGAN SYSTEM

• Circulatory System,
• Digestive System
• Nervous System
• Excretory System

ORGANISMS

Digestion

It is the process of breaking down large insoluble food particles in the food into soluble small particles which can then be absorbed into the blood

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DIGESTION PROCESS

INGESTION –

• It happens with the help of mouth and tongue
• Taking in of food with the help of mouth.
• The teeth and tongue helps in churning the food and mixing with saliva.

DIGESTION –

• It happens with the help of stomach, intestine , pancrease and liver
• Breakdown of large insoluble particle into small soluble ones

ABSORPTION –

• Small Intestine
• The process by which digested food particles are absorbed into the blood

ASSIMILATION –

• In the body cells
• Using the absorbed food for releasing energy and in body processes.

EGESTION –

• By rectum and Anus
• Getting rid of undigested food materials.

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BILE JUICE

• It is the green yellow alkaline liquid which is produced in the liver and stored in the Gall Bladder.
• It performs two major Functions:

NEUTRALIZATION

• The food that comes from the stomach is acidic and the enzymes of the intestine can work in alkaline conditions.
• The bile neutralizes the food that comes from the stomach and makes it alkaline so that the enzyme released in the intestine can work effectively.

EMULSIFICATION OF FATS

• For lipase to work, the fat must be broken down into small droplets to increase the surface area for the lipase to function.
• The bile perform this function of emulsification of fats for the efficient working of lipase.

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COMPONENTS OF FOOD

ENZYMES

• They are biological catalyst that increases the rate of a biological reaction without being used up.
• They increases the rate of the reaction by providing an alternative route that works by lowering the activation energy.
• They are protein in nature so they are sensitive to heat and pH.

LOCK AND KEY MODEL

Enzymes are highly specific due to the active site. As the active site has a shape complimentary to the substrate. So the specific substrate molecule can fit into the active site of the enzyme.

FACTORS AFFECTING ENZYME ACTIVITY

SUBSTRATE CONCENTRATION

ENZYME CONCENTRATION

FACTORS AFFECTING ENZYME ACTIVITY

Temperature

• Rate of reaction increases as particles gain kinetic energy and they collide more increasing
• The optimum temperature. It is the point where the enzyme activity is the highest.

pH

• Different enzymes has different pH optimum.
• Stomach enzymes works in acidic conditions which are maintained by hydrochloric acid Intential enzymes works in alkaline pH maintained by bile

CIRCULATORY SYSTEM

The system that provides the bosy with oxygen, nutrient, hormones and all the essential things required by the body to survive. It also eliminate the waste products.

PUMPING ORGAN

• It the heart that pumps the transporting medium all around the body.
• HEART

TRANSPXTING MEDIUM

• It is the blood which contains all the dissolved substances and oxygen required by the body.
• BLOOD

VESSELS

• They carries the blood from one part to another.
• ARTERIES
• VEINS
• CAPILLARIES

BLOOD

BLOOD PLASMA

• It is the liquid component of the blood.
• It makes 55% of the blood.

It is composed of:-

• Glucose
• Amino Acids
• Hormones
• Waste Products like Urea
• Carbon Dioxide

BLOOD CELLS

RED BLOOD CELLS

• It transport oxygen all around the body. It is a specialised cells
• Biconcave disc
• Increases the surface area for oxygen transport
• No nucleus
• To provide more room for oxygen contains haemoglobin
• Binds with oxygen to carry it around the body

WHITE BLOOD CELLS

• They are soldiers of the cells
• The protect the body from infections
• They are made up of lymphocytes which produce antibodies.
• They also have phagocytes which engulfs the pathogen

PLATELETS

• They are involved in blood clotting
• They have fibrin proteins which forms the mesh around the blood

NEED FOR CIRCULATORY SYSTEM

LOW SURFACE AREA TO VOLUME RATIO

• Multicellular organisms due to their bigger size have very low surface area to volume ratio.
• As a result, diffusion alone is not effective to meet the demands of the cell so it requires a circulatory system.

METABOLICALLY ACTIVE

• The multicellular organisms are metabolically active. So they need constant supply of oxygen and food and constant removal of waste products.

MULTICELLULAR

• Being multicellular many cells are deep and the diffusion distance is larger.
• So they need a circulatory system that transport substance deep inside the cells.

DOUBLE CIRCULATON

• In One complete cycle the blood is pumped into the heart twice.
• It involves two circulation: Pulmonary: Circulation between Lungs and Heart
• Systemic Circulation: Circulation between heart and the body
• Double circulation makes the circulation more efficient by preventing the mixing of oxygenated blood and helps to alter the pressure from the different chambers of the heart

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Heart        

• Heart is the pumping organ
• Working all day and night
• It has four chambers
• Atrium are at the top and Ventricles are at the bottom.
• Ventricles have thicker wall than the atrium.
• Left Ventricle have the thickest wall amongst all other chamber

BLOOD VESSELS

CORONORY HEART DISEASES

• Coronory Artery that supplies the blood to the arteries become narrow.
• The fatty materials like cholesterol gets deposited and narrow the artery.
• The narrowed artery reduced the blood flow to the heart.
• The blood flow to the heart is reduced.
• The heart do not get enough oxygen.
• This causes heart pain, chest pain and heart attack.

Treatment of Coronory Heart Disease.

• A Stent is placed with the baloon in the blocked artery.
• The blocked artery is opened by inflating the baloon.
• The metal mesh stent keep the stent in place.
• This resumes the blood flow.
• People can also be given statin which lowers the blood cholesterol and prevent the deposition of the cholestrol.
• The blood flow to the narrow artery is byepassed to the graft taken from another part of the body

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PROBLEMS TO THE HEART

LEAKY VALVES

• Due to increases pressure of blood flow the valves start to leak.

VALVE REPLACEMENT

• The valves made up of metal or polymers or the biological valves from animals can be used to replace the faulty valve

IRREGULAR HEART BEAT

• The natural pacemaker which are the group of cells at the top of the right atrium that regulates the heart beat do not function properly.

ARTIFICIAL PACEMAKER

• Electrical devices called the artificial pacemaker takes over the function of natural pacemaker.

HEART FAILURE

• When the heart do function properly

HEART TRANSPLANT OR ARTIFICIAL HEART

• Artificial heart or heart transplant from the donor.

HUMAN GAS EXCHANGE SYSTEM

MECHANISM OF BREATHING

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GAS EXCHANGE

ALVEOLI

GREATER SURFACE AREA

SHORTER DIFFUSION DISTANCE

STEEP CONCENTRATION GRADIENT

ORGANISATION IN PLANTS

CELLS

TISSUES

• Xylém and Phloem
• Palisade mesophyll tissue
• Spongy mesophyll tissue

ORGANS – Root, Stem and Leaves

ORGAN SYSTEM – Water Transport System

ORGANISM

TRANSPIRATION

• Transpiration is the loss of water from the surface of the leaves in the forms of water vapours.
• In plants it takes place through the stomata.

FACTORS AFFECTING TRANSPIRATION

MEASURING RATE OF TRANSPIRATION

• Potometer is the device which is used to measure the rate of water uptake or the rate of transpiration.
• The movement of bubble is an indicator of water movement which in turn shows the rate of transpiration

ADAPTATIONS TO LIMIT TRANSPIRATION

• Cuticle layer on the leaf which is waterproof prevent rate of transpiration
• Stomata are present on the lower surface to reduce rate of transpiration.
• Some plants stomata open is night and closes in day.
• In plants like cactus the leaves are reduced to spines to decreases the surface area for water loss.
• Some plants have sunken stomata.

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Disclaimer:

I have tried my level best to cover the maximum of your specification. But this is not the alternative to the textbook. You should cover the specification or the textbook thoroughly. This is the quick revision to help you cover the gist of everything. In case you spot any errors then do let us know and we will rectify it.

References:

BBC Bitesize

Wikipedia

Wikimedia Commons

Image Source:

Wikipedia

Wikimedia

Commons

Flickr

Pixabay

B4 Organinsing Animal And Plants