Biology - Summer Exam

• It allows us to move and bend dynamically
• Although our muscles give us strength, the bones support our body when carrying something heavy.
• They give our organs protection (Ribcage protects the hears)
• The production of White blood cells in bone marrow

Bone is a composition of Calcium Phosphate and Collagen

A joint is:

Where 2 or more bones meet.

4 common types:

• Fixed Joint - Cranium (Skull)
• Hinge - Elbow, Ankle and Knee
• Pivot - Neck
• Ball and Socket - Leg, arm, hip and shoulder

Fixed Joint - These joints are immovable, these are held together by fibrous connective tissue, composed of Collagen.

Hinge Joint - Where two bones meet, but has limited movement, it can only flex and extend, or move in two dimensions

Pivot joint - It allows the neck to pivot, or rotate

Ball & Socket - The "ball" slots into a "socket". Allows the leg, arm, shoulder and hip to move in three dimensions. Surrounded by synovial fluid.

Tendon - Tough cord that does not stretch, attaches the muscle across joints

Cartilage - Tough, smooth substance that covers the end of bones

Ligament - A tough band of fibres that joins bones together in a joint

Synovial Fluid - Lubricates the joint

Synovial Capsule - Encloses the fluid in the joints

Antogonistic muscles are a pair of muscles that do the opposite to each other.

An example of this is the triceps and biceps, if you straighten your arm, the biceps relax and the triceps contract.

If you bend your arm, the opposite happens, your biceps contract, and your triceps relax

• Fish swim by contracting the muscles down each side of the body in turn.
• The muscles pull on the vertebral column and produce wave-like undulations which travel down the length of the fish pulling sideways and backwards against the water.

• Dorsal Fin (top) - Balance
• Pectoral fin (side, come in a pair) - steering
• Pelvic Fin (Bottom, towards the back) - Steering
• Anal Fin (Bottom) - Balance

• Pitch - Up and Down
• Roll - Turning on Y axis
• Yaw - Turning on X axis

Water can support an animal with a large mass (e.g. Whale, its organs do not get crushed by water pressure)

Walkers:

• Body Position - Straight, rigid
• Leg bend - Almost no bend
• Arm Swing - Small swings
• Lift off the ground - None/Very litte lift

Sprinters

• Body Position - Relaxed, Streamlined
• Leg Bend - A lot of bend for maximum stride length
• Arm Swing - Large Swings for minimal resistance and increased power
• Lift off the ground - A lot of lift for maximum thrust and power

• In order to run the person must generate enough thrust to overcome the effects of drag

• Thrust - The action which the animal uses to push against the environment in order to move
• Drag - The force which the environment exerts to resist the animal's forward movement

What kinds of forces do plants have to withstand?

• Rain
• Predators
• Wind
• Snow

Plants are supported by:

• Presense of lignin as the plants matures e.g. Tree trunks contain a lot of lignin
• Strong roots - Good anchorage
• Plant cells take in water into their vacuoles, pressing out against the cell wall, making the cell stiff/rigid. This is called Turgor Pressure, whickh makes the cell turgid

We need food for:

• Energy
• Growth and Repair
• Health

Carbohydrate - Found in Bread, potato and cereal (sugar and starch are also carbs) - Needed for energy

Protein - Found in meat, fish and eggs - Needed for Growth and Repair

Fat - Found in for Cream, butter, milk and oil - Needed for a store of energy

Vitamins - Found in Vegetables and cereal - Needed to keep things 'ticking over'  (Vit D means Healthy bones - Vit A means good eyesight)

Minerals - Found in Meat, milk and cereal - Needed for strong bones (Calcium keeps bones strong - Iron keeps blood good)

Fibre - Found in Fruit, Veg and cereal - Needed to keep you regular

Water - Found in Water and most foods - Needed for hydration

Balanced Diet - The correct amount of all the nutrients and having the necessary energy requirements

Carbohydrate - Found in Bread, potato and cereal (sugar and starch are also carbs) - Needed for energy

Protein - Found in meat, fish and eggs - Needed for Growth and Repair

Fat - Found in for Cream, butter, milk and oil - Needed for a store of energy

Vitamins - Found in Vegetables and cereal - Needed to keep things 'ticking over'  (Vit D means Healthy bones - Vit A means good eyesight)

Minerals - Found in Meat, milk and cereal - Needed for strong bones (Calcium keeps bones strong - Iron keeps blood good)

Fibre - Found in Fruit, Veg and cereal - Needed to keep you regular

Water - Found in Water and most foods - Needed for hydration

Iodine

• Drop some iodine onto the food. If the iodine turns blue/black then starch is present

Simple Sugars (e.g. Glucose)

• Boil the food in Benedict's solution. If an orange precipitate appears then the food contains simple sugars

Protein

• Add 10 drops of Biuret solution to the food in a test tube. If protein is present$, it will produce a purple product

Vitamin C

• Crush up food, add a few drops of water and stir
• Take the solution and add it to a DCPIP Solution
• Keep adding until the DCPIP is decolourised.

Fats

• Shake or crush the food to make it dissolve.
• Filter or dilute the food and ethanol mix so that you get a clear liquid (a solution of fat in ethanol).
• Add this to a test tube of water. A white (milk-like) emulsion indicates the presence of fats or oils.

Metabolic Rate - The speed at which such chemical reactions take place in the body.

It varies because of several factors, including:

• Age
• Gender - male or female
• The proportion of muscle to fat in the body
• The amount of exercise and other physical activity
• Genetic traits

The metabolic rate increases as we exercise and stays high for a while afterwards.

Herbivore - Animals that only eat plants

• Butterflies
• Rabbits
• Hippos

Carnivore -Animals that only eat flesh (meateaters)

• Tigers
• Lions
• Bears

Insectivore- Animals that only eat insects

• Anteater
• Spider
• Lizard

Omnivore - Animals that eat flesh and plants

• Pigs
• Badgers
• Mice

Incisors -

Cutting teeth used for pieces of food

Canines -

These are long and sharp teeth used to tear and hold food

Premolars -

These are used to crush and grind soft food

Molars -

Used for chewing and grinding hard food

Teeth                     Milk                     Adult

Incisors                   8                           8

Canines                  4                           4

Premolars               4                           8

Molars                    4                          12

TOTAL                  20                          32

• The important part of an enzyme is called the active site.
• The shape of the active site is affected by pH
• Change the pH and the enzyme stops working.
• Increasing the temperature to 60°C will cause a permanent change to the shape of the active site.
• When enzymes stop working when they are heated, we say they have become denatured.

• Digestion breaks up large food substances into small, soluble molecules for absorption into the blood
• Enzymes speed up chemical reactions including the breakdown of substances
• Enzymes are specific for each reaction.
• Carbohydrases break down carbohydrates, proteases break down protein and lipases break down fats
• The small intestine completes digestion and absorbs the soluble molecules
• The food moves along the digestive system by peristalis - a series of wave-like muscle contractions that moves food to different processing stations in the digestive tract

• Independent variable - The variable you change
• Dependent Variable - The variable that changes and you measure
• Control Variable - Must not be changed to maintain a fair test

The process of producing energy in the body from food --> Glucose using Oxygen

Anaerobic Respiration - The release of energy without Oxygen

Glucose --> lactic acid + some energy + CO2

Aerobic Respiration - The release of energy using Oxygen

                                         enzymes

Fermentation = Glucose -------> Energy + Ethanol + CO2