OCR Gateway GCSE - Biology B1

OCR Gateway GCSE - Biology B1

1. Diet and excercise

   • Blood pressure can be measured two ways: Systolic and Diastolic in mmHg
   • Smoking can being overweight can affect your blood pressure making it higher
   • High blood pressure can lead to strokes and can damage the kidneys
   • Fitness is your ability to do physical activities compared to health which is how free of diseases you are etc...
   • Your EAR is used to calculate how much protein you need
   • BMI used to determine whether you are under, over or average weight

2. Drugs and disease

   • Immunisation protects against certain diseases by using harmless dead pathogens
   • How much a drug can harm you goes in up class (C-A)
   • Depressants and stimulants affect the transmissions crossing synapses.
   • Mosquitos are a vector that carry malaria
   • Plasmodium is the pathogen that causes Malaria

3. Homeostatis and plant hormones

   • Homeostatis is maintaining a constant internal environment
   • Vasolidation (widening) and vasoconstriction (tightnening) regulate the temperature of the body
   • Plant hormones can be very useful in commercial uses e.g selective weedkiller
   • Auxins are involved in Phototropism and geotropism
   • Insulin controls levels of sugar within the body. It converts excess blood sugar into glucose.

4. The nervous system

   • Light rays are refracted as they pass through the cornea and lens
   • The eye shape accommodates by altering the shape of the lens
   • Long sightedness and short sightedness are caused by the eyeball or lens being the wrong shape
   • Monocular vision has less depth perception but a greater FOV
   • Nerve impulses travel along the axon of a neurone
   • A neurotransmitter substance differs across a synapse, so the nerve impulse can pass to the next neurone
   • A spinal reflex involves a receptor, sensory relay and motor neurons and an effector.

5. Variation and inheritance

   • Alleles are different versions of the same gene
   • Sex is determined by the chromosomes either XX or XY
   • Human body cells have 23 pairs of chromosomes
   • Inherited disorders are caused by faulty alleles
   • Dominant alleles are expressed if present, recessive alleles are expressed in the absence of a dominant allele.
   • Most faulty alleles are recessive