Science Yearly

Energy and Sustainability

Important Notes:

• The Law of Conservation of Energy states that energy can't be created or destroyed, only transferred to another form.

Definitions

Circuits

Electricity flows through electrical circuits. For electricity to flow, the circuit must be a complete loop. A simple circuit must contain:

• A power source: such as  a battery or a power point

• Wires: which allow the electrons to flow

• A switch: so the circuit can be turned on or off

• A load: The device that is using the electricity

Examples of Energy

• Electric energy

• Kinetic energy

• Nuclear energy

• Hydro energy

• Solar energy

• Wind energy

• Thermal energy

• Clean energy

• Chemical energy -> food

• Magnetic energy

• Gravitational energy

• Sound energy

• Potential energy

Potential and Kinetic Energy

• Kinetic energy is the energy of movement

• Potential energy is the energy that can be used, it's stored energy. Many times this will happen when the object isn't moving.

• Potential energy is converted into kinetic energy e.g. Battery producing electricity. There are times when kinetic energy can be converted into potential energy e.g. Hydroelectricity, wind power, solar power .

Energy Transformations

• Energy cannot be created or destroyed - it is only transferred from one form to another. When you turn on a lamp, electrical energy transfers to light energy. When a solar panel absorbs sunlight, light energy converts to electrical energy.

• Energy transformations involve energy changing from one form into another.  For example, when a light bulb is switched on, electrical energy is transformed into light energy.  This can be represented as a flow diagrams:

   

  Electrical Energy → Light energy

Spheres of The Earth

Geosphere

• rocks

• minerals

• soil

• nutrients

Biosphere

• animal

• bacteria

• fungi

• plants

Atmosphere

• oxygen

• carbon dioxide

• nitrogen

Hydrosphere

• oceans

• seas

• rivers

• ponds

• lakes

Transfer of Heat Energy

Conduction is the transfer of heat energy via particle collisions within a substance or between substances that are in contact with each other. 

Thermal conductors are materials that readily transfer heat by conduction.

Convection is the transfer of heat energy via the flow of fluids (liquids and gases), known as convection currents. Particles in fluids, such as liquids (water) and gases (air), can move around more than in solids. When a liquid or gas is heated, the particles move further away from each other and the substance expands. The hot liquid or gas is less dense than the cooler liquid or gas, so it rises into the cooler areas. The denser cold liquid or gas falls into the warm areas producing convection currents that transfer heat from place to place. Similarly hot air will rise and move into an area of colder air.

Radiation is the transfer of heat energy via the absorption of electromagnetic radiation, especially infrared radiation, but also visible light, UV light and microwaves. The degree of absorption (how much) of infrared radiation by a substance is affected by its composition (what it is made up of) and colour.

• Transparent and translucent substances mostly transmit radiation.

• Dark, opaque substances mostly absorb radiation.

• Light, opaque substances mostly reflect radiation.

What’s up Bud

Plant Systems

Plants are multicellular organisms and have organs that work together to keep it alive. Remember that the definition of an organ is a group of tissues that perform a function.

Each part of the plant has more complex systems in place in order to gain gases, nutrients and water from the environment and remove wastes.

Roots

Roots contain root hair cells which assist in the uptake of water and minerals in the soil. Root hair cells are ten times smaller than a human hair and cover the roots of plants. Because they are so small and thin, they have a large surface area, meaning more water and nutrients can be absorbed from the soil.

Stem

Stems contain the transport system required to deliver water and nutrients from the roots to all other parts of the plant. To do this, they require two types of tissue: xylem and phloem.

Leaves

Leaves have many functions. One is that they act like the excretory system of a plant: they remove wastes produced during photosynthesis and cellular respiration. These gaseous wastes such as oxygen, carbon dioxide and water vapour are removed by the stomata in the leaves in a process called Transpiration. The stomata are tiny pores in a plant leaf that can open and close to allow for gas exchange.

Some plants store their waste products in their leaves and then drop the leaf. Other plants can store waste as resin, gum, oil, latex and bark which can seep out or be shed off. For humans, this is a useful aspect of plants as we can use these waste products to create things like medicine. 

Reproduction and Pollination

Structure of Flower

Flowers are the sex organs of plants. Like humans, you can have entirely male or female plants, such as kiwi fruit, cycads, holly, bay trees, stinging nettles and poison ivy. You can also have plants where the male and female parts occur on the same individual plant. Only about 6% of flowering plants have separate male and female plants, the rest have flowers which contain both sexes.

Pollination

Pollination is when pollen grains reach the stigma and start the fertilisation process. Plants pollinate themselves in four different ways.

Define pollination:  The movement of pollen grain from the anther to the stigma

Self-Pollination

1. Define self-pollination.

When the pollen is deposited on the flowers stigma, from the same flower's anther, it can also occur when the anther releases pollen and it lands on a different flower's anther, although the two flowers must be from the same plant.

Cross-Pollination

1. Define the term cross-pollination.

Where two different plants of the same species pollinate each other

Insect Pollination

1.  List the three defining features of insect pollinated flowers.

• Brightly coloured petals

• Strong Scent

• Nectary - produce nectar

1. Why does an insect pollinating flower produce nectar?

Provides a source of food for insects, drawing them in

1. What features do the pollen have?

• Sticky so that it sticks to an insect's body

• Edible for insects

1. When two organisms benefit each other, this is called: Mutualism

1. What are some examples of pollinators other than insects?

• Birds

• Lizards

• Bats

Wind Pollination

1. Why don't wind pollinated flowers look colourful or smell nice?

Because they do not rely on the attraction of an animal

1. Why do wind pollinated flowers have exposed anthers?

So that they can easily release the pollen into the wind

1. Compare the pollen grains of wind pollinated flowers to insect pollinated flowers. Why are they different?

They are smaller and light weight, while insect pollinators are larger, sticky and heavy, often lesser in number

1. How are stigmas in wind pollinated flowers different to insect pollinated flowers?

Wind pollinated flower's stigma's are exposed with a 'brush' to capture pollen.

Fertilization

Seeds

Seeds are the result of fertilisation and are the embryo of a plant. The ovule becomes the seed around the embryo to protect it. The ovary grows into a fruit to nourish and further protect the seed. Some seeds can be without a fruit and disperse with wind, like dandelions or maple trees. Fruits attract animals that can ingest the seeds and disperse them elsewhere.

Photosynthesis

Plants can obtain water and nutrients from their environment but must make food for themselves in the form of glucose which can then be broken down in cells. To do this, plants perform a process called photosynthesis which uses sunlight to convert water and carbon dioxide into glucose and oxygen.

Sunlight and Chlorophyll

Plants use the energy of sunlight to produce glucose and oxygen. Sunlight is necessary to trigger the reaction between carbon dioxide and water. This is a complex chain reaction which involves chlorophyll. Chlorophyll acts like a catalyst during photosynthesis - it absorbs sunlight and converts it into chemical energy which can then be used to synthesise glucose and oxygen.

1. Glucose is produced during photosynthesis and is then converted to starch and stored. Explain why starch is produced in leaves. Refer to the photosynthesis equation in your answer.

Starch is produced because glucose is used to 'power' the plant, this means that without glucose the plant would die, glucose is formed through photosynthesis, which needs carbon-dioxide, water, and sunlight as well as chlorophyll, this means that for example during the winter months where there is less sunlight, the plant will instead of using all of its glucose from the summer, it will turn it into starch so that it may be stored for future use.

Photosynthesis equation:

sunlight

water + carbon dioxide → oxygen + glucose

chlorophyll

Plants and Ecosystems

All living things on Earth exist within an ecosystem. Ecosystems across the word vary and include rainforests, tundra, deserts, marine environments and grasslands.

Producers

• Define a "producer".

An organism that creates it's own food

• What are some examples of producers?

Plants, eg. Trees that produce glucose through photosynthesis

Bacteria, using chemical energy

• From where do producers get their energy? What is the process that producers use to make their energy?

From sunlight or chemicals

Decomposers

• Define a "decomposer".

An organism that breaks down dead organic matter

• What are some examples of decomposers?

Fungi, bacteria, invertebrate

• What do decomposers produce that can then be used by producers?

Protiens

Consumers

• How do consumers gain their nutrition?

Utalise another organism

• Complete the table for the different types of consumers:

Food Chains

 All organisms in an ecosystem require energy. Producers are autotropic and produce energy from sunlight. Producers introduce energy into an ecosystem and it is then consumed by each trophic level above. As each consumer feeds on the tiers below, the initial energy is lost through heat, respiration and decomposition. Only about 10% of the energy is passed on to each level in a trophic pyramid.

The trophic pyramid can be converted into a series of food chains. Food chains show the direction in which energy flows in an ecosystem. A food chain starts with a producer and then add each trophic level in a line. Arrows separate each organism; the arrow means "is eaten by" and points in the direction of energy flow.

Producers à Primary Consumers à Secondary Consumers à Tertiary Consumers

E.g. Grass à Rabbit à Snake à Hawk

In this example, the producer is grass. Grass is eaten by the rabbit which is the primary consumer and a herbivore. The snake is the secondary consumer and eats the rabbit. The hawk eats the snake and is the tertiary consumer. Both the snake and the hawk are carnivores.

Food Webs

Food chains can be connected together as food webs. Food webs show the interactions of many organisms in an ecosystem. Food webs have a similar structure to a trophic pyramid: producers are at the bottom and consumers are layered above. in an ecosystem. Food webs have a similar structure to a trophic pyramid: producers are at the bottom and consumers are layered above.

Food webs can give us insight into the impact changing numbers of organisms can have on an ecosystem. Sometimes, removing organisms from an ecosystem has no impact. However, in most cases, the complex interactions of ecosystems means that removing organisms can have devastating effects and lead to the collapse of an ecosystem. If the producers are removed, the entire web will collapse.

Human Impacts on Ecosystems

Humans have been permanently altering the planet for a long time. Through industrialisation, we have negatively impacted the ecosystems of the Earth in various ways.

Upsetting the Balance

The Carbon Cycle

The Carbon Cycle is essential for life on Earth. It is the system that recycles carbon atoms to be used in the air, soil, rocks and living organisms. In our universe, no matter can be completely destroyed and it can not be made from nothing - instead matter is transformed from one form to another. The carbon in your body in the form of glucose is broken into carbon dioxide which can then be used by plants.

There has always been a natural Greenhouse Effect which has kept our planet warm with the small amount of greenhouse gases - namely carbon dioxide but also including methane, water vapour and various nitrous oxides. Unfortunately, due to human activity and the burning of fossil fuels, the delicate balance of the carbon cycle has been disrupted. This this has resulted in the Enhanced Greenhouse Effect which has contributed to climate change and the warming of the planet.

Positive Human Impacts

While human activity can be very damaging to the environment, it isn't all bad news. As a species, we have seen our impact on the ecosystems around us and are trying to fix our mistakes. An example of the positive impact humans can have on the environment is Conservation

Throughout the world, we have conservation practices and programs in place to try to preserve and repair ecosystems. National Parks are areas of land which have been sectioned off specifically for conservation purposes. There are many laws surrounding the use of National Parks to ensure ecosystems and habitats within them are protected. In 1872, the first national park was established in America with the acquisition of Yellowstone National Park. This sparked a global trend for governments to buy and protect large areas of the natural environment. In Australia, the first was the Royal National Park in Sydney, established in 1879. Since then it is estimated that we have around 680 parks nationally.

While we try to conserve our land, we also try to protect the organisms that live within it. In 1973, the Convention on International Trade in Endangered Species of Wild Fauna and Flora was created with a treaty signed by 80 nations to protect organisms worldwide. This put restrictions on the trade of organisms classified as endangered and most importantly gave a classification system for identifying and defining endangered and threatened species. Organisations such as the World Wildlife Fund make it their mission to conserve natural resources and animals and raise awareness for the conservation effort.

The Nitrogen Cycle

Another essential cycle for life on Earth is the Nitrogen Cycle. Nitrogen is necessary for all living things as it makes the bases of their DNA. Nitrogen-fixing bacteria in the soil convert atmospheric nitrogen to a form that plants can absorb. When organisms decompose, the nitrogen in their cells returns to the soil and can also be absorbed by plants as nutrients. As plants are producers, they then introduce nitrogen to all other organisms in an ecosystem.

However, human activity can also upset the balance of the nitrogen cycle. Fertiliser contains nitrogen to enrich the soil and grow crops faster on farm land. When it rains, water dissolves this nitrogen and it enters waterways and river systems through run off. As plants in water systems, mainly algae, also love nitrogen as a nutrient, this results in an explosion of their growth. This causes eutrophication.

Invasive Species

Australia is home to unique organisms and delicate ecosystems. We have marsupials such as the koala and kangaroo of which there are no other similar animals around the world. Other than New Guinea, we are also the only country to have monotremes. As Australia has been largely untouched and unconnected to other continents for millions of year, our animals have evolved separately and are highly adapted to the harsh Australian climate. While this can be a good thing, it also means that small changes to the environment can have devastating effects on our ecosystems.

When Europeans colonised Australia they also introduced new species of plants and animals to the country. The livestock animals like sheep, cows and horses, compacted the soil with their hard hooves thereby destroying the nutrient-rich, fertile soil. Introduced species outcompeted native animals for resources and also became their predators. Many native animals lived in ecosystems that did not have a large number of predators, and so their populations were greatly affected. It is estimated that 100 plant and animal species have become extinct in the 230 years since Europeans colonised Australia. The number of mammals lost in this period is about 10%, which is greater than any other type of organism.

Pollution

There are many different forms of pollution that can affect ecosystems. Pollution is when contaminants are introduced into a natural environment which can have harmful or poisonous effects. There are seven major types of man-made pollution: air, water, soil, light, noise, radioactive and environmental.

In the 21st century, much of our pollution is caused either by industrial processes (which can lead to issues like acid rain) or plastic waste. Choose a type of pollution and research the following:

• What causes this type of pollution? How is it formed?

• What impact does it have on the atmosphere, biosphere, lithosphere or hydrosphere? (This will depend on the type of pollution you choose. Your choice may affect every sphere or only a few)

• What impact does it have on the environment and ecosystems?

• What impact does it have on humans?

Natural Events and the Impact on Ecosystems

Across the world, communities are facing more extreme weather patterns due to climate change. Floods, droughts, wildfires, even cyclones can all be influenced and made more extreme by climate change. Australia experiences all four of these natural events yearly and so there is a great drive to reduce the impacts of these on ecosystems and communities.

Drought

• Species of plants that ae not drought tolerant will die, and therefore be replaced by other plants that are drought friendly, the characteristics of these 'drought friendly plants' are that they have smaller and harder leaves, therefore better suited for the heat.

• Australia is the driest continent on earth, that in most areas in Australia it is necessary for irrigation if crops that are not drought friendly want to live and thrive.

• Drought can also cause other problem/ dilemmas like bushfires, due to the dry environment.

Floods

• When lots of rain falls in a short period of time, it can cause flooding

• This can impact agriculture through the destroying of crops and feed as well as drowning or injuring livestock, floods can also cause destruction to cities and towns, this can be very costly

• However, floods also have benefits, in some places, flood water is the only water they will get, like in a desert, or can be used to help fertilise soil, like in the Nile, or even wash away polluting chemicals

Cyclones

• Develop when a low pressure system forms over the warm oceans of the tropics, when they develop in the Southern Hemisphere, there are very fast winds in a clockwise direction and thunderstorms are formed

• Are common in the summer months (for the northern part of Australia) and cause significant damage to buildings, infrastructure, farming, trees

• Can cause flooding and affect our ecosystem

Chemistry

Classification of Matter

In chemistry, matter is classified into two different groups:

1.  Pure substances

2. Impure Substances/Mixtures

Technology and Understanding

As technology changes, it helps us to improve our understanding of scientific principles. This is especially true of our understanding of the elements, their structure and properties.

The Elements

 Some elements we have known since ancient times, like gold, silver and copper. Other elements were discovered over time by different scientists. The earliest chemists were alchemists which was a medieval science which tried to accomplish feats such as turn other materials into gold and discover a universal cure for disease.

The Atom 

After determining at elements were substances that could not be broken down, scientists began to try and determine from what they were made. Ancient Greeks gave society the idea that elements were Earth, Fire, Air and Water and this was the main school of thought for close to 2000 years.

Eventually scientists performed experiments and found evidence for the fact that there were actually many elements that made up our world and that these elements were made of atoms.

Technologies

Early scientists in the 1700s had very simple equipment to perform experiments and learn more about elements. French chemist Antoine Lavoisier even created his own lab equipment to conduct his experiments. Scientists of his time who made the first discoveries of elements, mostly burned and weighed compounds to note and calculate differences seen.

Metals

Metals are the largest group of elements.  About three- quarters of elements are metals.

Metals have the following physical properties:

1. They are good conductors of electricity.

2. They are good conductors of heat.

3. They are malleable ie. Easily shaped.

4. They are ductile ie. Able to be made into wires.

5. They have a shiny lustre.

6. They have high melting points and boiling points.

Periodic Table

1. Hydrogen (H)

2. Helium (He)

3. Lithium (Li)

4. Beryllium (Be) 

5. Boron (B)

6. Carbon (C)

7. Nitrogen (N)

8. Oxygen (O) 

9. Fluorine (F)

10. Neon (Ne)

11. Sodium (Na)

12. Magnesium (Mg)
13. Aluminum (Al) 

14. Silicon (Si)

15. Phosphorus (P)

16. Sulfur (S)

17. Chlorine (Cl)

18. Argon (Ar)

19. Potassium (K)

20. Calcium (Ca)

Tests

Pop Test

When hydrogen gas is present, there will be a pop sound.

Method: 

1. Pour in hydrochloric acid, about 3 cm high.

2. Drop magnesium strip into hydrochloric acid. 

3. Immediately cover the mouth of test tube with thumb, to prevent any gas from escaping.

4. Wait about a minute.  When gas has built up, light a match and place into mouth of test tube and observe.

Scientific Method

Rules for writing a method:

• A list of numbered steps

• Be as specific as possible. Even when describing your equipment and chemicals, you should include the sizes and quantities to be used. You want your experiment to be reproducible (someone should be able to follow your method and obtain the same results)

• Include evidence of controlled variables

• Include evidence of reliability (i.e. Have a step to repeat the experiment at least three times)

• Include a step instructing how the data is to be recorded

• No personal pronouns

• When writing in present tense, start every sentence with a verb

Also, remember the rules for writing a risk assessment:

• Outline the risk involved. Remember the risk is the actual harm that can be caused. E.g. It is not a risk to break glassware but it IS a risk that broken glassware can cause cuts.

• Include harm minimisation strategies. This can be PPE (e.g. goggles, gloves, heatproof gloves), chemical handling (e.g. work in a ventilated area) or strategies to limit risks caused by equipment (e.g. move glassware to the centre of the table)

• It is easier to present your risk assessment in a table format, like so:

After having thoroughly researched a topic, you should have some prediction about what you think will happen in your experiment. This educated guess concerning the outcome is called your hypothesis.

The hypothesis is worded so that it can be tested in your experiment. Do this by expressing the hypothesis using your independent variable and your dependent variable. Not only must you incorporate all these variables in your hypothesis, but you also must express them in a way that you can readily measure.

Recall that a hypothesis is written as an "If...then" statement. It ties your independent and dependent variable together AND makes a specific prediction of the outcome. Essentially, the format is:

If the specific change in the independent variable, then outcome in the dependent variable

Observation: An observation is something that you experience directly through one of your five senses (sight, hearing, smell, taste, or touch).

Inference:  An inference is a conclusion that you reach after making an observation. It is based on one or more observations, plus other information.

Validity

• If an experiment is valid, the only cause for the effect you see is what you've tested for

• To be valid in an experiment:

1. Variables are well controlled

2. Tests the stated hypothesis

• Aspects affecting validity:

1. The equipment

2. The experimental method

3. The analysis of results

Reliability

• Experiments need to be repeated enough times for the results to be statistically accurate. Three trials are usually enough to minimise any errors

• To be reliable an experiment must:

1. Be repeated

2. Have consistent results

3. Be repeatable (and achieve the same results)

Accuracy

• The accuracy of your experiment is how close your result gets to the expected result. Accuracy can be improved by gathering measurements with more sensitive equipment. Reducing errors makes experiments more accurate

A results table should be drawn before your experiment, as it provides a place for all your experimental data to be recorded accurately. To design a proper table, you must firstly understand what data you will be collecting. Firstly you need to:

• Identify the independent variable

• Identify the dependent variable (including what units)

• Know the number of trials for each independent variable

A table should always:

• Be fully enclosed

• The independent variables is recorded in the first column and the dependent across the top of your table

• All units should be in headings and not recorded in individual cells

• If recording multiple trials, the value for each trial should be included and the averages (mean) should be calculated and recorded in a separate column

• A title for the table eg "The Effect of (independent variable) on (dependent variable)"

• Each column should have headings at the top

Human Biology

Comparing Photosynthesis and Respiration

1. Why is cellular respiration important?

It is important because living organisms generate energy for activities through cellular respiration, it is creating ATP energy, Adenosine triphosphate

2. Where does cellular respiration occur in an organism?

The Mitochondria.

3. What are the reactants and products of respiration?

Sugar combines with oxygen to produce carbon dioxide and atp

Word equation for respiration:

mitochondria

Glucose + oxygen → water + carbon dioxide

• Explain how the processes of photosynthesis and respiration are linked.

Both processes use the same materials, just in reverse order

Body Systems

cells → tissues → organs → organ systems → organism

Briefly explain how each of the following body systems assist the survival of cells within an organism:

• Digestive system:

Breaks down food so that it can be converted to energy

• Circulatory system

Distributes blood throughout the body

• Respiratory system

To help the body to breathe and remove carbon dioxide

• Excretory system

To expel waste

Respiratory System

What are the three main functions of the respiratory system:

1. Bring in air

2. Make the air warm and damp

3. Bring the air and blood close enough for gas exchange to happen

How does oxygen get into the blood?

Your lungs aren't hollow spaces, they are more like a sponge filled with tubes called bronchioles that are like tree branches that spread into each lung. At the end of each bronchiole are air sacs called alveoli. The alveoli of the lungs are surrounded by capillaries. The blood in the capillaries contains red blood cells and flows in one direction around the alveoli.

Draw gas exchange:

1. Oxygen is carried to all parts of your body in your blood.

1. Another name for alveoli is air sac.

1.  the bronchial tubes start at the bottom of your lungs.

1. Dirt is kept out of your lungs by tiny hairs called cilia.

How do we breathe?

Breathing is the action of inhaling air into the body and exhaling the air in our lungs.

When inhaling, the diaphragm (a sheet of muscle) contracts and moves down. The intercostal muscles (muscles between our ribs) contract and the ribs expand. Air is drawn into the lungs.

When exhaling, the diaphragm relaxes and moves upwards. The intercostal muscles relax and the ribs move closer. Air is expelled from the lungs.

When the diaphragm is relaxed, the person exhales, when the diaphragm is contracted, the person breaths in.

Cardiovascular System

1. What is the main role of the circulatory system: 

   1.   Transport nutrients, oxygen, gasses and waste. 

   2.   To keep the blood moving in the body 

   3. Supply every part of the body with blood 

   4. To circulate the blood past the lungs for gas exchange. 

1. What is the function of the circulatory system? 

The function of the circulatory system is to push blood around and through our body, actings as both a delivery of nutrients and oxygen and as a waste removal of carbon dioxide. 

2. Why does blood need to be pumped around the body. 

Blood needs to be pumped around the body to keep organs and cells healthy and to keep us alive. 

3. Describe the three components of the circulatory system. 

• The heart is the 'heart' of the circulatory system --> helps to pump blood throughout the body. 

• The heart is made of 4 chambers, the left and right atriums located at the top of the heart and the left and the right ventricles at the bottom of the heart. 

• The rest of the circulatory system is made of two independent networks that works together, these are called the pulmonary and systemic systems. 

Pulmonary:

• Responsible for providing fresh oxygen to the blood and to remove the carbon dioxide within the body. 

Systemic: 

• A system/ series of arteries, veins and capillaries --> the pathways that delivers oxygenated blood (from the Pulmonary) from the left side of the heart to the whole body --> all the organs, tissues cells etc. It also returns the deoxygenated blood to the right side of the heart. 

The heart is the pump that pushes blood around the body. It has four chambers the right atrium,  the left atrium, the right ventricle and the left ventricle . The walls of the chambers are made of _________________ . Blood enters the (1) right atrium and passes down into the (2) right ventricle. As this chamber fills with blood, (8) valves float up to close off the right atrium. The wall of the right ventricle contracts to push the blood out through the (3) pulmonary artery to the rest of the body.

When the blood enters the lungs two things happen:

1. The blood deposits waste carbon dioxide gas from the body's cells.

2. The blood picks up oxygen gas, which is needed by all the living cells of the body.

Blood and Blood Vessels

Blood carries the nutrients and water obtained from digestion and the oxygen from breathing in, to all the cells around the body. It also carries the carbon dioxide and other waste products from the cells. The average human body contains about 5 litres of blood made up of red blood cells, white blood cells, platelets and plasma.

There are 3 main types of blood vessels:

1. Arteries

2. Veins

3. Capillaries

There are three types of blood cells , each type has their own function. Explain the function of each type of cell:

1. Function of erythrocytes:

To transport gases in the blood, mainly carrying oxygen from the lungs to the body and returning carbon dioxide to be exhaled

2. Function of leukocytes:

In the immune system that protects the body

3. Function of thrombocytes:

 cell fragments essential for hemostasis, a process that stops bleeding by forming a plug at a wound site and initiating blood clotting

Digestive System

What are the 6 processes that the digestive system is responsible for:

1. Ingestion - Get food and drink into body

2. Propulsion - moving down to digestive tract

3. Mechanical digestion - physically breaking nutrients down, e.g. teeth

4. Chemical digestion - chemically breaking nutrients down, e.g. acid in stomach

5. Absorption - nutrients absorbed into blood stream

6. Defecation - getting rid of solid waste

1. What is a monomer?

Building blocks

1. What are examples of foods heavy with carbohydrates?

Pasta and bread

1. What are the functions of carbohydrates?

To give energy

1. What is the monomer for carbohydrates?

Monosaccharides

1. What are lipids better known as?

Fats

1. What are the two building blocks of lipids?

Fatty acid and Glycerol

1. What are 3 examples of lipids?

Butter, oil, cholesterol

1. What are the 3 functions of lipids?

Helps keep warm-insulating, provide long term energy, make up cell membranes

1. What are foods high in proteins?

Meat, beans

1. What is the monomer for protein?

Amino acids

1. What are the functions of proteins?

Immune system, act as enzymes

1. What do nucleic acids produce?

DNA and RNA

1. What are the monomers of nucleic acids?

Nucleotides

1. From what kinds of foods are nucleic acids obtained?

Anything that had previously lives, e.g. plants and animals

1. What three elements do all biomolecules contain?

Carbon, hydrogen and oxygen

Mouth

• Why should you chew your food? 

To break it down into smaller pieces so that food doesn’t get stuck in your gullet or lung airways, so you don't choke

• What is saliva? 

Saliva produced by salivary glands helps to moisten the food to help digest food, acts as lubricant to bring it down

• What is the role of the epiglottis? 

To bring food from mouth down to stomach

Stomach

• What happens to the walls of the stomach?

They churn and grind the up the food

• What are stomach juices? 

Hydrochloric acid, used to break down food

• What is churning?

Muscles in the stomach contracting

Small intestine 

• What is it’s role? 

To let the nutrients be absorbed into the blood stream

• Juices and enzymes are added, where do they come from? 

They come from the gall bladder, pancreas and liver.

Large intestine 

• What happens if food is left here for a long period of time? 

The waste dries out and becomes difficult to excrete, contipation

• What happens if food is only here for a short period of time? 

Can lead to diarrhea

Digestion occurs through both physical and chemical means. Physical digestion is when food is broken into smaller pieces. This can occur through chewing (the combination of our incisors, canines and molars cut, tear, grind and crush our food) or through the churning of our stomachs.

Chemical digestion uses enzymes to speed up the chemical reactions that help break down food into biomolecules. They can then to be absorbed from the small intestine into the circulatory system. Finger like projections inside the small intestine called Villi act to increase the surface area available for absorption of nutrients.

1. Name the products of digestion for each of the following

• Sugars and Starches - Simple sugar, e.g. glucose

• Protein - Amino acids

• Lipids - Fatty acids and glycerol

2. Name the enzymes used to break down each of the following

• Sugars and Starches - Amylase

• Protein - Protease

• Lipids - Lipase

Excretory System

The body has a number of ways of getting rid of the waste it produces.

• Carbon dioxide is released to the air by the lungs.

• Some wastes are released in sweat through the skin.

• Some wastes are released into the intestines by the liver.

• However, most wastes are removed from the body in urine.

Because of the importance of urine, the organs that produce and get rid of urine are called the excretory system. It has four organs:

• The organ that filters the blood to produce urine is called the kidney. Humans have two of them, located in the abdomen near the stomach.

• Urine is carried from the kidneys through long tubes called ureters.

• The urine is stored in a muscular pouch called the bladder.

• Finally, the urine is carried from the bladder out of the body through a tube called the urethra.

Kidneys

The Kidneys and Urine Production

• Many chemical reactions occur in the cells and there are many waste products from these reactions. Getting rid of wastes from cell reactions is called excretion.

• The liver cells makes urea which is toxic if present in the body in large quantities. Other cells in the body also make wastes which are released into the blood and carried to kidneys where they are filtered out of the blood and excreted from the body as urine.

• If kidneys do not work, a person could not survive. Their blood must regularly go through a dialysis machine so the wastes can be filtered from the blood.

Answer the following questions:

1. What is the main role of the excretory system?

To get rid of waste products

1. What produces waste products in our bodies?

Kidneys

1. What is the effect on the body if waste products are not removed?

We will be 'poisoned' and become very ill

1. Excretion is not the only function of the kidney's, what else does it do?

Filter blood, manage blood pressure and red blood cell production

1. Each kidney has a million tiny filters called nephrons. Which bodily fluid flows into nephrons?

Blood

Muscular-Skeletal System

1. The muscular skeletal system needs to be:

• strong and rigid, but it also needs to be flexible, moveable, and bendable

• able to perform big and strong movements, but also small, fine and accurate movements

1. What are the two components that make up bones?

   Calcium phosphate and collagen

The Skeleton

The human skeleton has three main functions:

• Support - the skeleton helps give your body its shape and helps you stand upright. The bones in your skeleton are strong but light.

• Protection - soft organs are protected by your skeleton e.g. Your skull protects your brain.

• Movement - muscles are attached to bones in the skeleton. Movement occurs at joints when these muscles apply forces to bones.

The human skeleton is made up of 206 bones. Using the internet or your knowledge, find the scientific names for the names of bones we use in everyday language.

Tendons, Cartilage and Ligaments

Muscles are necessary to help as move, as are our joints. However, they must be attached to the bones or held in place properly in order for movement to occur. This is the job of tendons, cartilage and ligaments - they help with the joint movement of muscles and bones.

Tendons join muscles to bones. Tendons provide a pulling force on a bone when a muscle contracts.

Think Tendon = Two Types (bone to muscle)

Ligaments hold two bones together and keep the joint from moving in a direction that would cause dislocations.

Think Ligament = Like with Like (bone to bone)

Sprains occur when ligaments or tendons are stretched or torn.

Cartilage is a tough, flexible material that forms a smooth, frictionless surface around a joint. It acts as a shock absorber when the bones in a joint move around each other. It can also be found in your ear lobes or at the end of your nose where it is needed for support.

Now, label the diagram below with the following terms: ligament, tendon, bone, cartilage.

Complete the summary:

1. What do tendons do?

Connect bone to muscle

2. What do ligaments do?

Connect bone to bone

3. What does cartilage do?

Acts as shock absorber and also support

Reproductive System

Define the following terms:

Male Reproductive System

Female Reproductive System

Part	Name of Part	Function
I	Fallopian tube	Carries the ovum (egg) from the ovary to the uterus
J	Ovary	(After puberty) An egg (ovum) is released from here once every month
K	Uterus	If an egg is fertilised, it will implant into the wall of the uterus (endometrium) and develop into a foetus
L	Cervix	The opening at the top of the vagina, leading to the uterus
M	Vagina	Connects the cervix to the outside of the body. Sperm is deposited here
N	Bladder

Fertilization occurs when the male gamete (sperm cell) fuses with the female gamete (the egg) to produce a zygote.  The zygote travels down the fallopian tube towards the uterus.  Along the way it divides multiple times and eventually becomes a blastocyst.  The blastocyst embeds itself in the lining of the uterus.  This process is called implantation and the blastocyst is now called an embryo.  As the embryo grows and becomes more complex, specialized cells and tissues start to develop.  It also starts to form most organs.  At the end of 8 weeks, it is now referred to as a foetus.

The Role of Cell Division

Three reasons why cells need to divide

(i) Repair

(ii) Growth

(iii) Reproduction

Mitosis is the process of cell division in which the daughter cells are genetically identical to the parent cell. This process occurs in body cells and is used for growth and repair of an organism. It is also used in asexual reproduction.

Every one of us began as just one cell, created when an egg cell and a sperm cell fused together. This process is called fertilisation. A fertilised egg cell contains DNA from both parents. This provides the genetic instructions for building a particular human being.

Meiosis is the process of cell division in which the daughter cells are genetically different to the parent. This process is used in sexual reproduction with the production of gametes (eggs and sperm). It occurs in the ovaries and testis (animals) or anther (flowers).

By increasing the number of cells in our bodies, cell division allows us to grow to adulthood.

And our cells don’t last forever. Scientists estimate that an adult human loses roughly 60 billion (60,000,000,000) cells per day! Fortunately, in that same day about 60 billion cells divide, replacing those that die. Many cell deaths are just part of the normal functioning of our bodies. Others are caused by damage or disease. Any damaged or dying cells must be replaced so that the tissue can be repaired.

The type of cell division that allows our bodies to grow and repair is called mitosis. Without it, we would never even develop from a single cell!

Technology

Types of technology helping systems:

• Pacemakers

• Kidney dialysis

• Sphygmomanometer

• Cardiopulmonary bypass

• Glucose monitors

• Inhalers for asthma