Biology - B1 Flashcards
What increases blood pressure?
- smoking
- a high alcohol intake
- a diet rich in saturated fats
- salt
What can high blood pressure do?
- it can damage the brain and also the kidneys
What is the definition of being fit and healthy?
- fit: the ability to do exercise
- healthy: being free from disease
What can the EAR be used to calculate?
- your protein requirements
What can your protein requirements depend on?
- age
- pregnancy
- lactation
What can the BMI be used to do?
- to indicate being over or under weight
What will a balanced diet vary according to?
- age
- gender
- activity
- religion
- personal choice
What can reduce the risk in cancer?
- positive changes to your lifestyle
What is a mosquito and what does it carry?
- it is a vector
- it carries malaria
What is plasmodium?
- it is the pathogen that causes malaria
- it is a parasite and humans are its host
What does immunisation do?
- it protects against certain diseases by using harmless pathogens
What are drugs classified as? Order from most harmful
- class a
- class b
- class c
What do depressant and stimulant drugs affect?
- the nervous system by affecting the transmission across synapses
What can high levels of alcohol cause?
- cirrhosis of the liver
What is homeostasis?
- it is maintaining a constant internal environment
What are the two readings of blood pressure and what are they measured in?
- diastolic pressure
- systolic pressure
- mmHg
What do automatic systems in the body do?
- they keep water, temperature and carbon dioxide levels constant
What does the hormone insulin do?
- it controls blood sugar levels and it converts excess blood glucose into glucogen
What do vasodilation and vasoconstriction do?
- they control heat transfer from the body
What are auxins a group of and why do they cause?
- they are a group of plant hormones
- they cause shoot curvature by cell elongation
What is phototropism and geotropism?
- phototropism: response to light
- geotropism: response to gravity
What are auxins involved in?
- both phototropism and geotropism
What are some commercial uses plant hormones have?
- selective weedkiller
- rooting powder
- control or fruit ripening
In which part of the eyes are light rays refracted?
- in the conea of the lens
How does the eye accommodate?
- by altering the shape of the lens
Which has a wider field view but poorer judement? Binocular or monocular vision?
- monocular vision
Where does the nerve impulse travel?
- it travels along the axon of a neurone
What does a neurotransmitter do and why?
- it diffuses across a synapse
- so the nerve impulse can pass to the next neurone
What does a spinal reflex involve?
- a receptor, sensory, relay, motor neurones and an effective
What are alleles?
- different versions of the same genes
How is sex determined by?
- sex chromosomes
What are the chromosomes in male and female (egg and sperm)?
- female: XX
- male: XY
How many chromosomes are there in a human body cell?
-23 pairs
How are inherited disorders caused?
- by faulty alleles
When are dominant and recessive alleles expressed?
- dominant: expressed if present
- recessive: expressed in the absence of a dominant allele
What is the difference between being homozygous and heterozygous?
- homozygous: having two identical alleles
- heterozygous: having two different alleles
Are most fault alleles dominant or recessive?
- recessive
