B1

Description

Science (B1) Mind Map on B1, created by georgia.somerville on 19/11/2013.
georgia.somerville
Mind Map by georgia.somerville, updated more than 1 year ago
georgia.somerville
Created by georgia.somerville about 11 years ago
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Resource summary

B1
  1. Fitness and Health
    1. Low blood pressure: - Dizziness - Fainting - Poor circulation
      1. High blood pressure: - Blood vessels burst - damage to brain (stroke) - damage kidneys
        1. Can be increased by stress, alcohol, smoking, being overweight
          1. Can be decreased by regular exercise and a balanced diet
          2. Blood pressure is measured in mm of mercury (mmHg)
            1. Systolic Pressure; maximum pressure the heart produces
              1. Diastolic pressure; the pressure between heart beats
                1. Fitness is the ability to do physical activity
                  1. Can be measured by Strength, Flexibility, Stamina, Agility, Speed
                  2. Health is being free from diseases
                    1. Smoking
                      1. Carbon Monoxide in cigarette smoke decreases the oxygen-carrying capacity of blood as it combines with haemoglobin, preventing it from combining with oxygen so less is carried.
                      2. Heart disease is caused by a restricted blood flow to the heart muscle.
                        1. Increased by: high levels of saturated fat, which leads to building up cholestrol
                          1. Narrowing of arteries caused by plaques in the coronary arteries can reduce blood flow to the heart muscle. Also makes blood clots or thrombosis, which will also block the artery.
                        2. Human Health and Diet
                          1. Carbohydrates- Simple sugars such as glucose
                            1. Stored in the liver as glycogen/converted into fats.
                            2. Proteins- Amino acids
                              1. Can't be stored in the body but are used to repair and for growth
                                1. EAR in g = 0.6 x body mass in kg
                                  1. Depends on certain factors; body mass, age, pregnancy or breast feeding,
                                  2. Too little protein can cause Kwashiorkor which is popular in LEDC'S due to lack of money to buy food.
                                    1. First class proteins - Meat and Fish. Contain Amino Acids which can't be made by the human body.
                                      1. Second class proteins - Plants proteins. Don't include all of the Amino Acids.
                                      2. Fats-Fatty acids and glycerol
                                        1. Stored under the skin/around organs.
                                        2. Balanced diet varies according to specific factors. Whether its your age, gender, level of activity, religion, vegetarian/vegan, or medical issues/food allergies
                                          1. BMI = mass in kg / (height in m)2
                                            1. More than 30:Obese. 25-30:Overweight 20-25:Normal. Less than 20: Underweight
                                          2. Staying Healthy
                                            1. Malaria
                                              1. Caused by protozoan called Plasmodium(parasites), which feeds on human red blood cells.
                                                1. Mosquito- Carries Plasmodium and is the vector, where as us humans are the host. It releases the Plasmodium into our bodies, which travels to our lungs and bursts our red blood cells.
                                                  1. Treatments - draining stagnant water, putting oil on it's surface and spraying insecticide to stop the mosquitoes life cycle
                                                2. Cancer
                                                  1. not smoking - prevents risk of skin cancer
                                                    1. Wearing suncream- prevents risk of skin cancer
                                                      1. Benign tumour cells (in warts) divide slowly and are harmless
                                                        1. Cancers are malignant tumours; the cells have uncontrolled growth and may spread
                                                        2. Pathogens(cause diseases) destroy the body cells or produce poisionous cells called Toxins.
                                                          1. The body protects itself by producing antibodies from the white blood cells resulting in active immunity
                                                            1. The antibodies protect us by locking onto antigens which are on the surface of Pathogens and kills them
                                                              1. Each Pathogen has it's own Anitbody
                                                            2. Vaccinations
                                                              1. Injecting a harmless pathogen which is carrying antigens. The antigens trigger the white blood cells which then sends out correct antibodies.
                                                                1. Memory Cells (T-lymphocyte cell) remain in the body which provides immunity against that disease.
                                                                  1. Tested on animals, human tissue and computers beforehand
                                                                2. An antiviral drug slows down the Pathogens development
                                                                3. Trials
                                                                  1. Blind trial, the patient doesn't know whether they're receiving a drug or a placebo. Avoid a 'feel- good factor' and a biased opinion.
                                                                4. The nervous system
                                                                  1. How do eyes work?
                                                                    1. Light rays are refracted (bent) by the cornea and the lens.
                                                                      1. Binocular vision helps to judge distance by comparing the images from each eye, the more different that they are, the nearer that the object is.
                                                                        1. Accommodation - Focusing light from distant or near objects by altering the shape of the lens.
                                                                          1. When focusing on distant objects, the ciliary muscles relax and the suspensory ligaments tighten so the lens has a less rounded shape. Vise-versa for focusing on near objects.
                                                                          2. Faults in vision
                                                                            1. Red- green colour blindness is caused by a lack of specialised cells in the retina
                                                                              1. Long sight - the eyeball is too short or the lens is too thin, so the image is focused behind the retina
                                                                                1. Convex lens
                                                                                2. Short sight - the eyeball is too long or the lens is too rounded so the lens refracts light too much so the image would be infront of the retina
                                                                                  1. Concave lens
                                                                                3. Nerve Cells
                                                                                  1. Nerve cells are called neurones. Nerve impulses pass along the axon.
                                                                                    1. Reflex action is show by a reflex arc. Stimulus-Receptor-Sensory Neurone-Central Nervous System-Motor Neurone-Effector-Respone
                                                                                      1. Spinal reflex; Receptor-Sensory Neurone- Relay Neurone-Motor Neurone-Effector
                                                                                      2. Gap between neurones is called a synapse,
                                                                                    2. Drugs and you
                                                                                      1. Types of drugs
                                                                                        1. Depressants- Alcohol, Solvents, Temazepam
                                                                                          1. Block the transmission of nerve impulses across synapses by binding with receptor molecules in the membrane of the receiving neurone.
                                                                                          2. Painkillers- Aspirin, Paracetamol
                                                                                            1. Stimulants- Nicotine, Ecstasy, Caffeine
                                                                                              1. Cause more neurotransmitter substances to cross synapses.
                                                                                              2. Performance enhancers- Anabolic steroids
                                                                                                1. Hallucinogens- LSD
                                                                                                2. Effects of smoking
                                                                                                  1. Smoke contains many chemicals that stop cilia moving.
                                                                                                    1. Cilia-tiny hairs found in epithelial lining of trachea, bronchi and bronchioles
                                                                                                    2. Smokers cough- dust and particulates in smoke irritating the epithelial lining and mucus not being moved by the cilia.
                                                                                                    3. Effects of alcohol
                                                                                                      1. Increases reaction times and risk of accidents
                                                                                                        1. Cirrhosis of the Liver- Liver is damaged when it breaks down toxic chemicals such as alcohol.
                                                                                                      2. Staying in balance
                                                                                                        1. Homeostasis
                                                                                                          1. Definition- Keeping a constant internal environment
                                                                                                            1. Involves balancing bodily inputs and outputs
                                                                                                              1. Automatic control system keeps the levels of temperature, water and carbon dioxide steady
                                                                                                                1. Negative feedback controls are used in it. Act to cancel out a change such as decreasing temperature level.
                                                                                                                2. Temperature control
                                                                                                                  1. Normal body temp: 37 degrees celscius
                                                                                                                    1. High temp can cause: heat stroke, dehydration
                                                                                                                      1. Low temp can cause: hypothermia
                                                                                                                        1. Blood temp is monitored by the hypothalamus gland in the brain. Reaction to temp extremes are controlled by the nervous/hormonal systemss which trigger vasoconstriction/vasodilation
                                                                                                                          1. Vasoconstriction - Narrowing of small blood vessels in skin. Causes less blood flow/less heat transfer.
                                                                                                                            1. Vasodilation- widening of small blood vessels in skin. Causes more blood flow near the skin surface resulting in more heat transfer
                                                                                                                          2. Control of blood sugar levels
                                                                                                                            1. Insulin- hormone, control blood sugar levels
                                                                                                                              1. Converts excess glucose in the blood into glycogen, stored in liver
                                                                                                                              2. Type 1 diabetes- Pancreas not producing any insulin, must be treated by insulin
                                                                                                                                1. Insulin varies according to the persons diet/activity. Big effort of exercise needs more glucose to be in the blood, so lower insulin is then required.
                                                                                                                                2. Type 2 diabetes- Body producing little insulin or body not reacting it, can be controlled by diet
                                                                                                                              3. Controlling plant growth
                                                                                                                                1. Plant responses
                                                                                                                                  1. Phototropism - a plant's growth response to light.
                                                                                                                                    1. Geotropism - a plant's growth response to gravity.
                                                                                                                                      1. Shoots are positively phototropic and grow towards the light, and are also geotropic as they grow away from the pull of gravity.
                                                                                                                                        1. Roots are negatively phototropic and positively geotropic.
                                                                                                                                        2. Plant hormones (auxins)
                                                                                                                                          1. Auxins- group of plant hormones, more through the plant in solution
                                                                                                                                            1. They are involved in phototropism and geotropism
                                                                                                                                              1. Different amounts of auxins are found in different parts of the shoot when the tip is exposed to light. Auxin is mostly found in the shady parts of the shoots.
                                                                                                                                                1. Higher amount of auxin = increased length of cells
                                                                                                                                                  1. Therefore, an increased amount of cell length on the shady side causes for the shoot to curve towards the light
                                                                                                                                                    1. If tip is removed, will not grow
                                                                                                                                                    2. Uses
                                                                                                                                                      1. Used as a selective weed killer, which kill specific weeds and increase the crop yield
                                                                                                                                                        1. Root powder to increase root growth of cuttings
                                                                                                                                                          1. Delay fruit ripening to meet market demands
                                                                                                                                                            1. Control dormancy in seeds
                                                                                                                                                          2. Variation and inheritance
                                                                                                                                                            1. Inherited characteristics
                                                                                                                                                              1. Inherited characteristics can be dominant or recessive
                                                                                                                                                                1. They depend on dominant and recessive alleles
                                                                                                                                                                  1. Dominant alleles- expressed when present
                                                                                                                                                                    1. Recessive alleles- only in the absence of the dominant allele.
                                                                                                                                                                  2. Alleles- different versions of the same gene
                                                                                                                                                                  3. Chromosomes
                                                                                                                                                                    1. Human cells have 23 pairs.
                                                                                                                                                                      1. Female - XX
                                                                                                                                                                        1. Eggs only carry X chromosomes
                                                                                                                                                                        2. Male - XY
                                                                                                                                                                          1. Sperm carries either X or Y chromosomes
                                                                                                                                                                          2. Random chance - equal chance of the offspring being male or female
                                                                                                                                                                          3. Genetic variation
                                                                                                                                                                            1. Caused by
                                                                                                                                                                              1. Mutations - random changes in the genes or chromosomes
                                                                                                                                                                                1. Rearrangements of genes during the formation of gametes
                                                                                                                                                                                  1. Fertilisation - zygote with alleles from father and mother
                                                                                                                                                                                2. Monohybrid cross
                                                                                                                                                                                  1. Involves 1 pair of characteristics controlled by a single gene, one allele being dominant and the other being recessive
                                                                                                                                                                                    1. Homozygous - identical alleles
                                                                                                                                                                                      1. Heterozygous- having different alleles
                                                                                                                                                                                        1. Genotype - genetic make up
                                                                                                                                                                                          1. Phentoype - alleles are expressed
                                                                                                                                                                                          2. Inherited disorders
                                                                                                                                                                                            1. Caused by faulty alleles, mostly recessive
                                                                                                                                                                                              1. Possible to predict the probability of inheriting such disorders by interpreting genetic diagrams.

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