Download Question How quickly do bacteria reproduce in ideal conditions? B2

B2 – Keeping Healthy
Q1
Question
How quickly do bacteria reproduce in
ideal conditions?
Answer:
Every 20 minutes.
B2 – Keeping Healthy
Q2
Question
If you start with 1 bacterium that
reproduces every 20 minutes, how
many bacteria will you have after 5
hours?
Answer:
32768
B2 – Keeping Healthy
B2 – Keeping Healthy
Q3
Question
Give three examples of the body’s first
line of defence?
Answer:
Skin
Tears
Stomach acid
Earwax
Mucus
Q4
Question
What is the function of the immune
system?
Answer:
To deal with any infectious
microorganisms that enter the body.
B2 – Keeping Healthy
Q5
Question
What are the roles of the two types of
white blood cell?
Answer:
One type engulfs and digests any
‘foreign’ material.
The other type produces antibodies
against specific microorganisms.
B2 – Keeping Healthy
Q7
Question
What is an antibody?
Answer:
Proteins that are specific to a
particular antigen. They are produced
by white blood cells.
B2 – Keeping Healthy
Q6
Question
What is an antigen?
Answer:
A chemical marker on a cell surface.
Antibodies will attach to them if they
are the right shape.
B2 – Keeping Healthy
Q8
Question
What do antibodies do?
Answer:
• They bind to pathogens and
damage or destroy them.
• They coat pathogens, clumping
them together so that they are
easily ingested.
• They bind to and neutralise
viruses or toxins.
B2 – Keeping Healthy
Q9
Question
Explain why you are immune to most
diseases that you have already had.
Answer:
Some white blood cells stay in the blood
after the original infection has cleared.
These memory cells can reproduce quickly if
the same antigen is encountered again. This
means that the microorganism is killed off
before you become ill.
B2 – Keeping Healthy
Q11
Question
What is herd immunity?
Answer:
It is a form of immunity that occurs
when the vaccination of a significant
portion of a population (or herd)
provides a measure of protection for
individuals who have not developed
immunity.
B2 – Keeping Healthy
Q10
Question
What is a vaccine?
Answer:
It contains dead or inactive
microorganisms. These act as
antigens. When injected into the body,
they stimulate white blood cells to
produce antibodies against the
pathogen.
B2 – Keeping Healthy
Q12
Question
Why are vaccines not risk free for
everyone?
Answer:
Some people may have serious side
effects.
Genetic differences mean that people
react differently.
B2 – Keeping Healthy
Q13
Question
Why do people need to get a flu
vaccination each year, but some
diseases only require a single
vaccination?
Answer:
The flu virus DNA mutates rapidly –
this means that it changes its antigens
and is no longer recognised by the
antibodies.
B2 – Keeping Healthy
Q14
Question
What is an antimicrobial?
Answer:
A chemical that can inhibit the growth
of microorganisms or kill them,
without damaging your own body
cells.
B2 – Keeping Healthy
B2 – Keeping Healthy
Q15
Q16
Question
What is an antibiotic?
Question
What is antibiotic resistance?
Answer:
A chemical that kills bacteria.
Answer:
Antibiotic resistance is when bacteria
are no longer killed by an antibiotic.
B2 – Keeping Healthy
Q17
B2 – Keeping Healthy
Q18
Question
Explain why antibiotics should not be
prescribed for someone with flu.
Question
Why are patients advised to finish a
course of antibiotics even if they start
to feel better?
Answer:
Antibiotics do not kill viruses and so
they would not work.
Answer:
Not finishing the course can increase
the risk of antibiotic resistant bacteria
emerging.
B2 – Keeping Healthy
B2 – Keeping Healthy
Q19
Question
Describe how new drugs are usually
tested before being prescribed for
human use.
Answer:
They are tested on human cells, then
live mammals (e.g. rats), then on
human volunteers.
Q20
Question
What is a placebo? Explain why they are
sometimes not used in drug trials.
Answer:
A placebo is a fake treatment. In trials
where patients are seriously ill, it would be
unethical to use a placebo as it would
prevent the patient from getting the
potential benefits of the new drug.
B2 – Keeping Healthy
Q21
B2 – Keeping Healthy
Q22
Question
What is meant by blind, double-blind and
open-label clinical trials?
Answer:
Blind – the patient doesn’t know if they
have the placebo or the drug.
Double-blind – neither the patient or the
doctor/scientist know who has the placebo.
Open-label – everyone is aware of the
treatment that has been received.
Question
The heart is a double pump, explain
what this means.
Answer:
The right side pumps deoxygenated
blood to the lungs, the left side pumps
oxygenated blood around the body.
B2 – Keeping Healthy
B2 – Keeping Healthy
Q23
Q24
Question
How is the structure of an artery
adapted to its function?
Question
How is the structure of a vein adapted
to its function?
Answer:
Arteries have thick, elastic walls to
enable them to withstand high
pressure.
Answer:
Veins have a large lumen to enable
blood to flow more easily; they also
have valves to ensure that blood flows
in the right direction.
B2 – Keeping Healthy
B2 – Keeping Healthy
Q25
Q26
Question
What is heart rate and how could you
measure it?
Question
When a blood pressure reading is
taken, what do the two values actually
measure?
Answer:
Heart rate is the number of times your
heart beats in one minute – it can be
calculated by taking your pulse rate as the
pulse is caused by blood being pumped
through by a heart beat.
Answer:
The higher reading is the pressure of
blood when the heart contracts, the
lower value is the pressure of the
blood when the heart relaxes.
B2 – Keeping Healthy
B2 – Keeping Healthy
Q27
Q28
Question
Describe one way in which high blood
pressure can lead to heart disease.
Question
Give three examples of lifestyle factors
that can cause heart disease.
Answer:
High blood pressure can damage the
lining of an artery.
Answer:
Poor diet
Smoking
Stress
Excess alcohol
Lack of exercise
B2 – Keeping Healthy
B2 – Keeping Healthy
Q29
Q30
Question
Explain how epidemiological studies
can be used to identify the risk factors
for heart disease.
Question
What is homeostasis?
Answer:
By studying groups of people it is
possible to look for similarities in
lifestyles that may be linked to heart
disease.
Answer:
The maintenance of a constant internal
environment.
B2 – Keeping Healthy
B2 – Keeping Healthy
Q31
Question
Name the three main components of
the body’s automatic control system.
Answer:
Receptor
Processing centre
Effector
Q32
Question
Give two ways that water is gained by
the body and two ways in which it is
lost.
Answer:
Gained: food, drink, respiration
Lost: sweating, breathing, in faeces
and urine.
B2 – Keeping Healthy
B2 – Keeping Healthy
Q33
Q34
Question
What factors can increase the
concentration of urine produced by the
kidneys?
Question
Which gland releases ADH?
Answer:
External temperature
Exercise
Intake of fluid and salts
Answer:
The pituitary gland.
B2 – Keeping Healthy
B2 – Keeping Healthy
Q35
Q36
Question
If there is an increase in water content
in the blood, will more or less ADH be
released?
Question
What effect does alcohol have on urine
production, why?
Answer:
Less.
Answer:
It inhibits ADH production, so the
kidneys reabsorb less water. Urine is
more dilute.