Fichas
Biology Unit 1
Fichas del conjunto (110)
- 1How are carbohydrates and fats used by the human body?Carbohydrates and fats are
used by the human body to
release energy. - 2How are proteins used by the human body?Proteins are used by the
human body to build cells. - 3How are mineral ions and vitamins used by the human body?Mineral ions and vitamins
are needed in small amounts
for healthy functioning of the
body. - 4What is meant when a person is malnourished?A person is malnourished is
they have an unbalanced
diet. - 5What can happen if a person is malnourished?If a person is malnourished, they
can become overweight or
underweight. They may also
develop deficiency diseases or
conditions such as Type 2
diabetes. - 6What happens to a person’s body mass if they take in less energy from their food than their body needs?If a person takes in less
energy from their food than
their body needs, their body
mass will decrease. - 7How does exercise affect the amount of energy that the body needs?Exercise increases the
amount of energy that the
body needs? - 8What is meant by a person’s metabolic rate.The metabolic rate is the rate
of all the chemical reactions
in the cells in the body. - 9How is a person’s metabolic rate affected by the amount of muscle that they have?Muscle tissue has a higher
metabolic rate than fat tissue.
So a more muscular person will
have a higher metabolic rate
than a less muscular person. - 10How is our body affected by inherited factors?Inherited factors affect our
metabolic rate (some people
have a genetically high metabolic
rate). Inherited factors can also
affect our cholesterol level - 11What is the effect of exercise on our health?People who exercise are
usually healthier than people
who take little exercise. - 12What did Semmelweis discover about preventing disease?Semmelweis worked at a hospital where women gave birth. Many women died of infections. Semmelweis realised that doctors often handled dead bodies before treating patients and were spreading infection. He suggested that they regularly wash their hands. This reduced the number of infections.
- 13What is meant by the word pathogen? Give two examples.Pathogens are microorganisms that cause
infectious disease. Examples are bacteria and viruses. - 14What is the key difference between bacteria and viruses in how they reproduce?Bacteria can reproduce on their own. Viruses can only reproduce when they are
inside living cells. - 15How do bacteria and viruses make us ill?Bacteria and viruses can make us ill by releasing toxins.
Viruses can also make us ill by damaging the cells in which they reproduce. - 16State three ways in which white blood cells defend us against pathogens.White blood cells defend against pathogens by:
• Ingesting pathogens (taking them in and destroying them).
• Producing antibodies which destroy
specific pathogens.
• Producing antitoxins which prevent toxins from harming us. - 17Which three diseases does the MMR vaccine protect us against?The MMR vaccine protects us from measles, mumps and rubella.
- 18How does vaccination protect us from disease?Vaccines contain small amounts of dead,
or inactive forms of a pathogen. They
trigger the body to produce antibodies. If
the person is infected by the pathogen in
the future, the body can now make
antibodies more rapidly and protect us
from infection. - 19How can the use of vaccines protect people who have not been vaccinated.If enough people have been vaccinated, then the spread of a pathogen is reduced. This helps protect people who have
not been vaccinated. - 20What do medicines such as painkillers do?Medicines such as painkillers
can help to relieve the
symptoms of a disease but do
not kill pathogens. - 21What do antibiotics such as penicillin do?Antibiotics are medicines which kill bacteria.
THEY DO NOT KILL VIRUSES. - 22Why do antibiotics not kill viruses?Antibiotics cannot kill viruses
because viruses live and
reproduce inside cells. - 23How are bacteria becoming resistant to antibiotics?Bacteria sometimes mutate and become
resistant. If we overuse antibiotics (or
use them when they cannot work e.g. for
viruses), then these resistant bacteria
have an advantage and resistance
spreads. This is called natural selection. - 24How can we prevent resistant bacteria (such as MRSA) from developing?To prevent resistant bacteria (such as
MRSA) from developing we must:
• Only use antibiotics when necessary
and use the correct antibiotic to kill a
specific bacterium.
• Never use antibiotics against viruses as
antibiotics do not kill viruses. - 25Why is mutation of pathogens a problem?When a pathogen mutates, existing antibiotics and vaccinations may not work against the new strain. This can allow the new strain to spread.
- 26Describe how natural selection leads to resistant strains of pathogens developing when antibiotics are used? (HIGHER TIER).• Mutation leads to a resistant strain developing.
• Antibiotics kill non-resistant pathogens.
• Resistant pathogens survive and reproduce so the population of the resistant strain increases. - 27Why do we need to develop new antibiotics?As bacteria become resistant to current antibiotics, we need to develop new antibiotics to treat bacterial diseases.
- 28Describe the stages of culturing a microorganism (very common question).• Sterilise petri dishes and culture growth medium
• Sterilise inoculating loops by passing through a flame.
• Tape the lid of Petri dishes shut to prevent microorganisms from the air contaminating the culture. - 29Why is it important that schools and colleges do not culture microorganisms at temperatures higher than 25C?If we culture microorganisms at 25C or lower then this reduces the chance of culturing pathogens that may be harmful to humans.
- 30Why are microorganisms used in industry cultured at temperatures higher than 25C?In industry, we want to grow microorganisms rapidly so we use temperatures higher than 25C.
- 31What do scientists call changes in the environment that we sense e.g. light, sound etc.Changes in the environment that we sense are called stimuli.
- 32What do we call cells that detect stimuli? Give examples.Cells that detect stimuli are called receptors. Examples include:
• eye - detect light
• ears - detect sound
• tongue and nose detect chemicals for taste and smell.
• skin - detect touch, pressure, pain and temperature - 33What is meant by a reflex? What is the advantage of reflexes?Reflexes are rapid, involuntary reactions. The benefit is that they can protect us from danger.
- 34State the stages in a reflex.• The stimulus is detected by a receptor.
• Electrical impulses pass along a sensory neurone.
• The impulse passes across a synapse (a chemical is released) to a relay neurone.
• The impulse passes across a synapse to a motor neurone.
• The impulse reaches the effector (eg a muscle or gland) and the response happens. - 35What is meant by an effector. State two examples?An effector brings about a response
• Muscles contract
• Glands secrete chemicals - 36State three ways that water can leave the body.Water can leave the body by:
• the lungs in breathing out
• the skin in sweating to keep cool
• the kidneys producing urine - 37State two ways that ions e.g. the sodium ion are released from the body.Ions are released by:
• The skin in sweating
• The kidneys when urine is
produced - 38Why is it important that the body temperature is controlled?The body temperature must
be controlled so that it is at the
temperature that enzymes
work best. - 39What are hormones?Hormones are chemicals
released by glands. They are
transported in the blood to the
organs that they control (the
target organs). - 40Why must the blood sugar levels be controlled?Blood sugar levels must be
controlled to provide cells with
a constant supply of energy. - 41State two glands which release hormones controlling a woman’s menstrual cycle.Hormones controlling a
woman’s menstrual cycle are
released by the ovaries and
the pituitary gland. - 42Describe the stages of the menstrual cycle.• Follicle stimulating hormone (FSH) released by the pituitary gland causes an egg to mature in the ovaries and triggers the ovaries to release oestrogen.
• Luteinising hormone (LH) triggers the release of the mature egg.
• Oestrogen from the ovaries inhibits the further production of FSH from the pituitary gland. - 43Describe how hormones can be used as an oral contraceptive.Oral contraceptives can
contain oestrogen and
progesterone. This prevents
eggs from being matured in
the ovaries. - 44Describe the problems with early contraceptive pills and how these were solved in modern versions.Early contraceptive pills contained
high doses of oestrogen and
caused side-effects. Modern pills
contain much lower doses of
oestrogen or progesterone only.
These have fewer side effects. - 45Describe how hormones can be used as fertility drugs.FSH and LH are used to stimulate
eggs to mature in a woman. The
eggs are collected and fertilised
with sperm from the father. The
embryos are inserted into the
mother’s uterus (womb) to develop - 46Describe how plant shoots are sensitive to light and gravity.Plant shoots grow towards
light (positive phototropism)
and away from gravity
(negative gravitropism). - 47What is the name given to the plant hormones that control growth towards light and gravity?Plant hormones are called
auxins. - 48Describe how plant roots are sensitive to moisture and gravity.Plant roots grow towards
moisture and towards
gravity. - 49What is meant by the words “phototropism” and “gravitropism”?Phototropism means growth in
response to light (eg shoots grow
towards light). Gravitropism
means growth in response to
gravity (eg shoots grow away from
gravity). - 50Describe how auxins are used in shoots to grow towards light.In shoots, auxins trigger cell
division. There is a higher level of
auxin on the darker side of a shoot,
so this side grows faster than the
light side. This causes the shoot to
grow towards light. - 51Describe how auxins are used in roots to grow towards gravityIn roots, auxins inhibit cell
division. There is a higher level of
auxin at the bottom side of a root.
This side grows slower than the
top, so the root grows downwards
(towards gravity). - 52How are plant hormones used by gardeners?Plant hormones are used by
gardeners to kill weeds and to
encourage roots to grow on
plants. - 53What is the first stage in the testing of new drugs?New drugs are first tested on
cells, tissues and animals. This
is to make sure that they work,
that they are not toxic and to
determine the best dose. - 54When drugs are first tested on humans, they are given in very low doses. Explain why.When drugs are first tested on
humans, they are given in very low
doses to check that they are safe.
Once we know they are safe,
further human trials determine the
best dose. - 55What is meant by a placebo?A placebo is a tablet or
injection which looks exactly
like a treatment but has no
active drug. - 56What is meant by a doubleblind drug trial?In a double-blind drug trial,
neither the patient nor the
doctors know which patient is
receiving the active drug and
which patient is receiving the
placebo. - 57What are statins used for?Statins are used to lower the
risk of heart and circulatory
diseases. - 58What was thalidomide originally developed for?Thalidomide was first
developed as a sleeping pill.
It was then found to reduce
morning sickness in
pregnant women. - 59What was the problem with thalidomide?Thalidomide had never been
tested on pregnant women (or
pregnant animals). Many babies
born to mothers who had taken
thalidomide were born with limb
abnormalities. - 60What is thalidomide used to treat now?Now thalidomide is used to
treat leprosy. - 61State two legal recreational drugs?Two legal recreational drugs
are alcohol and nicotine. - 62State three illegal recreational drugs.Three illegal recreational
drugs are ecstasy, cannabis
and heroin. - 63Why are ecstasy, cannabis and heroine harmful to the human body?Ecstasy, cannabis and heroin
may have harmful effects on
the heart and circulatory
system. - 64Why do people smoke cannabis and what are the negative side-effects?Cannabis makes people feel
relaxed and happy. It can cause
serious mental illness. People
who use cannabis sometimes move
onto more severe illegal drugs (eg
heroin). - 65Why do legal drugs (both prescribed and recreational) have a greater impact on health than illegal drugs?Legal drugs (prescribed and
recreational) have a greater
impact on health than illegal
drugs because far more
people use them. - 66What is the definition of a drug?Drugs change the chemical
processes taking place in
peoples’ bodies. - 67State two highly addictive drugs.Two highly addictive drugs
are heroin and cocaine. - 68If a person is addicted to a drug, what can happen if they stop taking it.If a person who is addicted to
a drug stops taking it, they can
suffer withdrawal symptoms. - 69State two examples of performance-enhancing drugs and describe what they do.Stimulants increase the heart
rate.
Anabolic steroids increase
muscle growth. - 70State four factors that plants compete for with other plants.Plants compete with other
plants for light, space, water
and nutrients from the soil. - 71State three factors that animals compete for.Animals compete for food,
mates and territory. - 72What do we call organisms that live in very extreme environments?Organisms that live in very
extreme environments are
called extremophiles. This
can include living at high
temperatures, pH etc. - 73Describe how camels are adapted to living in the dry conditions of the desert.Camels store fat in their hump. This can be respired, releasing water. By concentrating fat (which is an insulator) in one place, this allows heat to escape from other parts of the body. Camels can
tolerate increases in their body temperature,
without sweating. Large feet reduce the pressure on the sand, preventing camels from sinking in.
Camels have large eyelashes and can close their nostrils to prevent sand entering. - 74Describe how polar bears are adapted to living in the cold conditions of the Arctic.Adaptations to prevent heat loss:
• Thick layer of fat which acts as an insulator
• Large body = small surface area
• Thick fur
• Small ears = small surface area
• Fur on soles of feet for insulation
Other adaptations
• White fur = camouflage - harder for prey to see them - 75What can we say about the surface area of animals living in hot or cold conditions?Animals living in hot conditions
have a large surface area (eg
bigger ears) to increase heat loss.
Animals living in cold conditions
have a small surface area (eg
small ears) to reduce heat loss. - 76Describe how plants such as a cactus are adapted to living in dry conditions.Cacti have no leaves to reduce the
surface area that they can lose water
from. The stem of a cactus is used to
store water for use during very dry
conditions. Cacti have an extensive root
system to absorb as much water from the soil as possible. - 77State three ways that organisms can be adapted to deter predators.Adaptations to deter predators
include
• thorns
• poisons
• warning colours - 78State three changes in the environment that can affect animals and plants.Changes in the environment include:
• Change in a competitor
• Rainfall levels
• Temperature - 79Describe how lichens can be used as air-pollution indicators.Lichens are sensitive to air
pollution such as sulphur
dioxide. High levels of lichens
tell us that there is a low level
of air pollution. - 80Describe how invertebrate animals (animals without a backbone) can be used as indicators of dissolved oxygen in water.Some invertebrates required very high
levels of dissolved oxygen (eg mayfly
nymphs). If we see these e.g. in a river
then that tells us that there are high levels of oxygen in the water. Other organisms (such as Tubifex worms) indicate low levels of dissolved oxygen - 81Describe how energy passes into food chains.Plants absorb sunlight and convert
the light energy to chemical
energy in photosynthesis. This
chemical energy is stored e.g. in
glucose or starch. - 82What is meant by biomass?Biomass is the mass of living
material at each stage of a
food chain - 83Why does the biomass decrease at each stage of a food chain?Some material and energy is lost in
waste material released by
organisms. Energy is also wasted as
organisms respire (eg for movement).
Eventually this energy is transferred to
the surroundings. - 84State three conditions that increase the rate of decay of waste materials.Decay is carried out by
microorganisms. Microorganisms are
more active under the following
conditions:
• warm
• moist
• aerobic (oxygen present). - 85How does the process of decay allow plants to grow faster?When material is decayed, the
elements are recycled back
into the environment. Plants
can use these elements for
growth. - 86Describe the stages of the carbon cycle.• Plants and algae carry out photosynthesis, removing CO2 from
the atmosphere and storing the carbon as carbohydrates, fats and proteins.
• When plants respire, the carbon can be returned as CO2
• Animals get their carbon by eating plants (or other animals).
Some of the carbon is released as CO2 when animals respire.
• Animals release waste products. Microorganisms feed on this
and respire, releasing CO2.
• When plants and animals die, microorganisms feed on their
bodies and respire. The remaining carbon is released as CO2.
• Combustion of wood and fossil fuels release CO2 into the
atmosphere. - 87What is meant by the word gametes?Gametes are sex cells
(sperm and egg in humans,
pollen and egg in plants). - 88Why do plants and animals share similar characteristics as their parents?Plants and animals receive
genes from their parents
which is why they are similar
to their parents. - 89What do we find in the nucleus of cells?In the nucleus of cells, we find
chromosomes which are made
of DNA. - 90What is a gene?A gene is a section of a
chromosome that controls the
development of a
characteristic. - 91Why are organisms of the same species different?Organisms can have different
genetics or have been exposed to
different conditions (the
environment) or a mixture of both. - 92What is meant by sexual reproduction?In sexual reproduction, male and
female gametes join (fuse). The
offspring show variation because
they receive genetic information
from two different parents. - 93What is meant by asexual reproduction?In asexual reproduction there
is only one parent and no
joining of gametes. The
offspring are genetically
identical clones. - 94How can new plants be produced quickly?New plants can be produced
quickly by taking cuttings. The
new plants are genetically
identical to the original plant. - 95Describe how plant cloning can be carried out.In plant cloning, a small
group of cells is taken from the
original plant. These are
treated with hormones and
develop into a new plant. - 96Describe how animals can be cloned by embryo transplants.In embryo transplant, a developing
embryo is split into two before the
cells become specialised. The two
balls of cells (embryos) are
transplanted into host mothers and
develop into two clones. - 97Describe the stages of animal cell cloning.First the nucleus is removed from an unfertilised egg cell and the nucleus is thrown away. An adult body cell (eg skin cell) is taken from the adult to be cloned and the nucleus is removed. This nucleus is inserted into the empty egg cell. An electric shock triggers the cell to divide into an embryo. This is transferred into the womb of a female and develops
into a clone of the original adult who provided the skin cell. - 98Describe what happens during genetic engineering.First we identify a gene which is
desirable (eg in humans). The gene
is “cut out” of the chromosome of a
cell. This is done using enzymes.
The gene is then transferred into
the cells of other organisms - 99What do scientists call crops which have had genes transferred into them from different organisms?Crops which have received
genes from other organisms
are called genetically
modified crops (GM-crops). - 100Why are genetically modified crops produced?Genetically modified crops can be
made to be resistant to attack by
insects or resistant to herbicides
(weed killers). GM crops usually
show increased yield of crop. - 101What concerns do some people have about GM crops?Some people worry that GM
crops might be harmful to wild
flowers and insects as well
as human health. - 102What was proposed by Darwin in his theory of evolution by natural selection?Darwin proposed that all
species have evolved from
simpler life forms that first
developed more than three
billion years ago. - 103State three reasons why Darwin’s theory of evolution by natural selection was only slowly accepted.• Darwin challenged peoples’ belief
that God created all the plants and
animals on Earth.
• There was insufficient evidence
• How genetics operates was not
known until several decades later. - 104What was Lamarck’s theory on how organisms evolve? Why is this wrong?Lamarck proposed that when an rganism
uses a feature (eg a muscle) that feature
develops (eg gets bigger). This developed
feature is then passed onto the offspring (for example muscular parents producing
muscular children). We know that this is not possible in most cases of inheritance. - 105How can the similarities and differences between organisms give us clues about their evolutionary links?Organisms that have similar
features are likely to be
evolutionarily related (eg humans,
chimpanzees, orang-utans and
gorillas are closely related as they
share similar features). - 106Describe how evolution by natural selection takes place.• Organisms within a species show genetic variation.
• If an organism has an advantageous
feature, it is more likely to survive and
reproduce.
• The genes which confer the beneficial
feature are then passed on to the next
generation. - 107What can cause rapid changes in a species?When mutations produce a
new form of a gene, a species
can rapidly change if the
environment changes. - 108What is glucose used for in plants?S.P.a.R.C.S
Starch.Proteins.Respiration.Cellulose.Seeds - 109What are glucose and nitrates used for in plants?GrandmaNapsAtParties
Glucose + Nitrates -> Amino Acids + Proteins - 110What are proteins used for?PCASH
Proteins ->
Catalysts (Enzymes)
Antibodies
Structure
Hormones