Katie Biology Unit 1 revision

A Balanced Diet
1. A balanced diet means, that you eat something from each group, but in the right amounts of each.
  1. Protein
  2. Fat
  3. Fibre and Water
  4. Vitamins and Minerals
2. Carbohydrates
3. BMI
  1. BMI=Mass in kg/(height in M)2
  2. Underweight= under 18.5
  3. Normal= 18.5-25
  4. Overweight= 25-30
  5. Obese=over 30
    1. Health Problems: high blood pressure, diabetes, some cancers, gout, Osteoarthritis, breathing problems, gallbladder and gallstones.
4. Metabolic Rate Factors
  1. Is the speed at which chemical reaction happen in the cells of your body.
  2. Inheritance- the genes passed to you by your parents
  3. The proportion of muscles to fat in your body, the more muscle the higher your metabolic rate.
  4. Gender- men tend to have more muscle so have a higher metabolic rate.
  5. Age- younger people tend to have a higher metabolic rate then older people
  6. Controlling Fertility
    1. IVF- may be offered to couples that are infertile
      1. This is were fertility of the egg, takes place outside the body in a Petridis or test tube. Before the procedure takes place the women is given FSH and LH in a "Fertility drug" to stimulate the maturation of several eggs. The subsequent producer is show in diagram.
        In Vitro Fertilisation
    2. An ethical problem associated with IVF is that there is a low success rate and that any left over embryo's created can only be kept for 10 years and after that, they must be destroyed. As a consequence many embryo's die and this is an issue to the people who think embryo's have a right for life.
    3. Decreasing Fertility: the first Pill contained oestrogen in large close which worked by preventing the relics of the pituitary gland there by preventing eggs from maturing. However, these resulting in women having side effects. Many factors found that they could oestrogen which lowered the side effects. The mini pill just contains progesterone and isn't as reliable at preventing pregnancy.
    4. Tropism
      1. Slow plant responses are called tropisms. There are three stimuli that plants respond to: Light, gravity and water.
      2. A response to light is phototropism, gravity is Geotropism and water is Hydrotropism.
      3. Parts of a plant that grow towards the stimulus are classed a positively topic, e.g. leaves are positively phototropism phototropic and these the grow away from the stimuli and negatively phototropic, e.g. roots
      4. Growth in Plants: In plants cell division and growth takes place mainly at the root tips and the shoot tips.
      5. Control of Growth: the shoot tip makes hormones called auxin. It stimulates the shoot to grow and causes the cells to elongate. It passes on auxin through diffusion,
      6. How light affects growth: How is it controlled? When a shoot only gets light frim one side most auxin is found on the shades side.
        The auxin makes the shoot grown more on the shaded side.
        The shoot bends towards the light.
      7. How Gravity affects growth? If a plant it put on its side the auxin builds up on the lower side of the shoot and roots.
        If the shoot the auxin stimulates it to grow more on the lower side.
        This cause the shoot to bend upwards. In the root the auxin also builds up on the lower side. But auxin slows down growth in a root.
        So the upper side of the root grows quicker then the lower side. The root bends downwards.
      8. Using Plant Hormones
        Ethylene is a plant hormones produces by fruit as they ripen. Converting starch into sugar. Expose unripe fruit to ethylene gas.
        Weed Killer contains auxin. Causes rapid growth in plants, plant grow themselves to death.
        Root powder: Cuttings of plants are dipped in root powder. The hormone auxin in powder causes roots to grow.
      9. Drugs:
        A drug is defined as any chemical which alters the way the body works.
        1. Chemicals are identified that might make useful drugs.
        2. Small amounts of the promising chemical are made up and tested in the laboratory on human cell cultures and tissues (group of cells)to check for toxicity (safety).
        3. The drug is tested on small mammals like mice or rats and possibly on primates (monkeys).
        4. If early tests in the lab suggest the drug is safe to use on living things the the drug company can apply for a licence to test the drugs on humans.
        5. In phase 1 of the trial, a small number (10) of healthy, informed volunteers are given low does of the drug to check it is not toxic to humans.
        6. In phase 2, around 200 patients with the disease the drug is to treat are given to find the optimum (best) does of the drug.
        7. Placebo controlled, double blind trails takes place. Some patients receive the drug and some patients are given a placebo- this looks just like the real drug but doesn't contain the drug. The trail is double blind- because neither the doctor nor the patients know who has received the placebo or the real drug.
        8. Phase 3 of the trial extends to between 1000 and 3000 patients. If the medicine seems effective and safe a licence is applied for to enable doctors to prescribe it for a patient with that disease.
        Thalidomide
        Thalidomide was originally developed as a sleeping pill but in the 1950s and early 1960s doctors also found it could be effective for morning sickness.
        The unforeseen outcome of using thalidomide in pregnant women is that their babies were born with deformities.
        The doctors were not just aware of the outcome in the pregnant women they prescribed thalidomide because they hadn't done relevant testing.
        They boned it and stopped people using them. They used it for to try and treat bone marrow cancer.
        Drugs in sport
        Mask drugs: cant be found in urine, so hide other drugs taken, banded in all sport. Side effects dizziness and addiction.
        Beta Blockers: Slow heart beat, helps in archery to calm you down.
        Diuretics- don't effect performance it helps you lose weight quickly for sport with set weights, like house riding. Side effects are muscle cramps and they weaken.
        Pain Killers: treat pain, act on Brain and spinal cord. Can be used in any sport-not in compertion only in training. the side effects are vomiting.
        Anabolic Steroids: Stimulates muscle growth which increases strength and endurance. The hormones resemble testosterone and new molecules and bonds are made/formed in cells. The side effect are acne aggression and liver diodes.
        Competition
        Animals and plants have to compete for limited resources. The best adapted animals or plants will win and survive.
        There are four resources for which animals compete. They are: food, water, space/territory and to mate.
        Interspecies Competition: Outside the species.
        Intraspecies Competition: in the species
        Adaptation
        An adaptation is a special feature or behaviour that makes an organism particularly suited to its habitat.
        Competition in Plants
        They compete for water and nutrients from the soil. Tall plants such as trees prevent light from reaching the plants beneath them.
        Plants have many adaptations that make them good competitions.
        Adaptations in Plants
Diseases
1. A pathogen is a scientific term for a germ that makes you ill.
2. Bacteria makes you feel ill by dumping their toxic waste into your blood stream, which makes you feel ill.
3. Bacteria increase in number by halving them self's and double form there. In the right conditions they can double every 20 minutes.
4. Viruses damage the body, by injecting their DNA into a cell then destroys it making more every time in destroying the cell.
5. Barriers to Infection
  1. Eyes have lysozyme in our tears
  2. you nose has mucus in and it is sticky so bacteria get trapped in the nose hair
  3. Hair
  4. Your stomach is lined with mucus and has hydrochloric acid in there.
  5. Skin
  6. Finger Nails
  7. Scabs
  8. Mouth
  9. Reflex Action
    1. A reflex action is an in voluntary response which takes place automatically
    2. Reflex action are responsible for running everyday actions in your body and help you avoid danger.
    3. The pathway the electrical impulse takes is known as a reflex arched.
    4. The electrical impulse by passes the confuse area of the brain, so that time between the stimulus and the response is as short as possible.
  10. Hormones
    1. Water content: Water in drink and food enters the body.
      1. lost in sweat.
      2. Water lost when you wee as well as iron.
      3. Water is produced during respiration in every cell.
      4. Pituitary gland produces a hormone (ADH) that enables kidneys to reduce water lose
      5. breathing out
    2. Blood suger: Pancreas eating carbs and exercise both effect blood glucose levels.
      1. Insulin lowers blood gluecose.
      2. Blood glucose levels must be kept within limits.
    3. Controlling Temperature: core body temperature must be maintained at 37 degrees C. If we are too hot sweat evaporate to remove heat energy and more blood travels throught the skin to radiate.
      1. If we are too cold we shiver and muscle movement generates heat.
    4. Homestasis
      1. A hormone is a chemical produced in a gland in one part of the body (in glandular tissue), released into the blood stream and carried to a target organ where it brings about an effect.
6. Second Line of Defence
  1. If pathogens make it into the blood then white blood cells called phagocytes engulf them and destroy them.
  2. This is a non-specific response- it is the same for all pathogens
  3. Smallpox
    1. Epidemic- in one country (swine flu)
    2. When a pathogen mutates no one has immunity.
    3. When new strings are made they can spread rapidly from person to person, leading to epidemics (one country) or pandemics (more then 3 countries).
    4. Antibiotics and vaccines may not be effective to the new strain.
    5. Herd immunity- controls diseases.
      1. If the minority of the population is vaccinated against by a disease it is Herd immunity.
        It is very hard for it to be transmitted and the disease becomes controlled.
7. Third-Line of Defence
  1. Is the defence against infection it is called the specific reaction. When the white blood cells in the immune system recognises a foreign invading, they prepare a antibodies to fix it.
  2. The white blood cells try different antibodies until they find one that matches the antigen. The specific antibodies lock onto the antigen allowing the foreign body to be destroyed.
  3. Anti-Toxins
    1. Bacteria makes you feel ill by dumping toxins/waste into your blood. Some white blood cells can produce anti-toxins that nutrients these toxins.
    2. Antibiotic Resistance
      1. It means that bacteria's are no longer killed by antibiotics.
      2. Bacteria divides and a error is made in copying the DNA that leads to a mutation.
      3. The mutation is beneficial in that it confers resistance.
      4. This new strain of bacteria is not destroyed by the antibiotics.
      5. It survives to reproduce and pass on the beneficial mutation to its off spring.
      6. How Vaccines Work
        1. A vaccine containing dead or inactive forms of a pathogen enters the body and triggers the immune system to respond.
        2. White blood cell produce antibodies to attach to antigens on the surface of the dead or inactive pathogen in the vaccine.
        3.Each pathogen requires a specific antibody because the antigens on its surface are unique.
        4.The white blood cells also make 'memory cells' that stay in your body for years.
        5. If the same microbe attacks that body in future, the memory cells produce antibodies to attack and destroy it quickly.
        6. You will not develop the symptoms again. You are now 'immune' to the disease.
    3. Receptors and Stimuli
      1. The nerverus system coordanates and controls you body. It makes you aware of changes in your surrodings and able to make you respond to them. A change in the environment is called a stimulus. Specialised cells in the sence organs can detect a stimulase are called receptor cells.
      2. Sight- in your eyes- dectected by light
      3. Taste- in your tongue- dectected by chemical in food.
      4. Touch- skin- dectected by pressure and temperature change.
      5. Smell- by your nose- chemicals in air
      6. Hear- by your ears- vibrations
      7. Balance- by your ears-posision
      8. Neurone
The Menstrual Cycle
1. The menstrual cycle is a sequence of events that takes place repeatedly during the fertile part of a woman life to enable for her to reproduce. There are several significant event that need to be coudanated if she is to has a successful pregnancy:
  1. Building up the lining of the uterus
  2. Maturing an egg (ovum) in to ovary- ovulation
  3. releasing egg from an ovary
  4. Main tainting the lining
  5. Breaking down of the lining passing it out the body- menstration
2. FSH- produced in the pituitary gland, targeted organ is the ovary and effects the mature of egg and produce oestrogen.
  1. LH- produced in the pituitary gland, targeting in the ovary's and causes ovulation (egg release).
    1. Oestrogen- produced in the uterus and pituitary gland, target organ is ovary, starts thickening of uterine lining and stops FSH released.
      1. Progesterone- produced in yellow body (empty follicle), targets the uterus and maintains thick lining of uterus.

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	Created by Megan Gair over 8 years ago