Growth and Development of Different Organisms
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Duncanrig Secondary School
S3 Biology Course
Growth and Development of Different
Organisms
Pupils’ Activity Booklet
Growth and Development of Different Organisms
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What you should know by the end of this unit:
Growth is defined as increase in size and mass during the development
an organism over a period of time. The growth of an organism follows an S-shaped curve, where growth is
slow at first, then fast then towards the end of life non– existent. Be able to identify the growth curve of an insect, annual plant, perennial
plant and human. Be able to explain the step-like appearance of an insects growth curve in
terms of shedding its hard exoskeleton and growth. Describe the life cycle of an insect. State that there are two phases of rapid growth in humans. These occur
during the first two years of life and during adolescence. State the importance of a balanced healthy diet to growth and
development. State the name of a variety of deficiency diseases in humans, their causes
and symptoms. State the effect of radiation on growth and development. State the effect of a variety of chemicals on growth and development of
organisms to include those in cigarette smoke, alcohol and lead.
Skills that you should be able to carry out by the end of this unit are:
Carry out research to link diet to deficiency disease.
Calculate averages and percentages.
Extract information from different sources.
Work as part of a group and take responsibility to support the work of the
group.
Write up experiments with an aim, method, results and conclusion.
Appreciate the importance of variables in an experiment and how to
improve the reliability of results.
Growth and Development of Different Organisms
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In this unit we will learn about the growth and development of different
organisms
Every organism has its own life cycle – a pattern of growth and change
that occurs over the organisms lifetime.
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In biology, growth is defined as increase in size and mass during the
development of an organism over a period of time. Growth is often
measured as an increase mass of organic material, excluding
water and is associated with cell division by mitosis.
All organisms grow, although the rate of growth varies over a lifetime.
Typically, growth in an organism follows an S-shaped curve, in which
growth is at first slow, then fast, then, towards the end of life, non-existent.
The S-shaped curve can be split in to 4 main growth phases.
Phase A-B shows a period of accelerating growth.
Phase B-C shows a period of steady rapid growth.
Phase C-D shows a period of decelerating growth.
Phase D-E shows a period of no growth. Different Growth Patterns
Copy the above graph into your jotter. Now add the information about
the four phases of growth onto your graph.
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Different types of organisms show variations in the basic growth curve.
The graph below shows the growth curve of an insect.
Insects e.g. locusts possess a hard inelastic outer skin called an
exoskeleton which prevents them from growing at a constant rate.
This skin must be periodically shed to allow growth to occur. A new
skin forms beneath the old one and when the latter is cast off during
moulting, the insect quickly inflates its body before the new skin
hardens. This produces an abrupt increase in body length giving the
graph its step-like appearance.
Collect a copy of resource sheet 1 from your teacher. Using the information about growth curves cut out and label the diagram showing the growth curve of an insect and glue it into your jotter.
Explain the step like appearance of the growth pattern of
an insect.
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Insects belong to a group of animals called arthropods. All arthropods have a
hard exoskeleton or cuticle, segmented bodies and jointed legs.
All but a few insects begin their lives as eggs (a few are born alive). Then from
the egg, a small immature insect emerges. Depending upon the group to which it
belongs, it will be either a larva or a nymph, but it may be called by various
names. For instance, the larvae of the familiar butterflies and moths are often
called caterpillars. Larvae of flies are called maggots, those of some beetles are
grubs, and juvenile mosquitoes are known as wrigglers. "Baby" bugs, which
closely resemble their parents in miniature, are just called nymphs.
As the immature larva or nymph feeds and grows. It enlarges by shedding its
rigid outer skin called an exoskeleton. Moulting can occur up to six times until
the insect finally reaches its adult size. The adults reproduce, the female lays her
eggs and the life cycle begins again.
Life cycle of a grass hopper
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Growth and development of Insects
Some insects have a more complex life cycle.
Butterflies undergo major developmental changes during growth. Like other
insects, eggs are laid which hatch into larvae called caterpillars. Caterpillars need
to eat and eat so they can grow quickly. When a caterpillar is born, they are
extremely small. When they start eating, they instantly start growing and
expanding. They grow by shedding the outgrown skin several times.
When they are finished growing and they have reached their full length/weight,
they form themselves into a pupa, also known as a chrysalis. From the outside
of the pupa, it looks as if the caterpillar may just be resting, but the inside is where
all of the action is. Inside of the chrysalis (pupa), the caterpillar is rapidly changing.
Within the chrysalis the old body parts of the caterpillar are undergoing a
remarkable transformation, called metamorphosis, to become the beautiful parts
that make up the butterfly that will emerge. Tissue, limbs and organs of the
caterpillar have all been changed. Finally the butterfly emerges from the chrysalis.
In the final stage of their lives the butterfly looks for a mate in order to
reproduce. The female will lay her eggs on a leaf and the life cycle begins again.
Collect a copy of the butterfly life cycle from your teacher.
Write a short summary detailing the main stages in the growth and development of a butterfly.
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An annual plant refers to a plant grown outdoors in the spring and summer
and surviving just for one growing season. All roots stems and leaves of
the plant die off annually. Only the dormant seed bridges the gap between
one growing season and the other.
In the growth curve of an annual plant (above), it can be seen at B there is
a decrease in mass. This is as a result of food stores being used up in the
seed during germination. However, soon green leaves develop,
photosynthesis begins and the plant gains mass. Towards the end of the
growing season the curve flattens out and declines as can be seen at point
C, as seeds are dispersed.
Collect a copy of resource sheet 1 from your teacher. Using the information about growth curves cut out and label the diagram
showing the growth curve of an annual plant. Describe what is happening at B and C, then glue it into your jotter.
annual plant.
Plant Growth Patterns
The graph below represents the growth curve of an
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Key Questions (Answer in sentences)
1. What is an annual plant?
2. Explain why there is a decrease in mass during seed germination.
3. What process occurs that allows the annual plant to gain mass?
4. What happens at the end of the life cycle to cause a decrease in
mass?
The graph below represents the growth curve of a
perennial plant.
Perennial plants grow year after year. The growth curve takes the form
of lots of s-shaped curves. Each year, spring and summer provide the best
growing conditions i.e. plenty of light and warmth for photosynthesis.
During winter, growth slows down and stops.
Collect a copy of resource sheet 1 from your teacher. Label the growth curve of a perennial plant. Explain why there are lots of s-shaped curves.
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Human Growth Pattern
The graphs below represents the growth curve for a human.
In humans there are 2 phases of rapid growth called growth spurts. The
first occurs in the first 2 years of life following birth (infancy) as can be
seen between points A-B on the graph above. The second occurs at puberty
(between points C-D on the graph) after a long period of steady growth.
A baby is about 20 inches long at birth (give or take an inch) and will
grow so at 2 years of age, the child will be about 35 inches tall. From 2
years until about 12 years of age, the child will grow at a steady rate of 2 to
2-1/2 inches a year. The growth spurt that goes along with adolescence
begins at about age 11 in girls and 13 in boys. This pubertal growth
spurt usually lasts 2 years and is accompanied by sexual development.
Growth stops between 16 and 18 years of age, when the growing
ends of the bones fuse. A person's adult height is determined by many
factors, including the heights of his or her parents, the age at which puberty
begins and the length and vigour of the pubertal growth spurt. An x-ray of
the hand or knee allows the doctor to assess the maturity of the bones
(bone age) and estimate how much growth potential remains.
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Collect a copy of resource sheet 1 from your teacher. Using the information about growth curves correctly label the growth curve of a human.
?
Key Questions (Answer in sentences)
1. At what age do the two growth spurts in humans occur?
2. What name is given to the second growth spurt?
3. What type of development occurs at this stage?
4. At what age do humans stop growing?
5. What factors determine a persons adult height?
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The food you eat and the life style you live play an important role in how
healthy you are, how you develop and your life expectancy.
A healthy body:
Food is needed by the body to:
1 provide it with fuel for energy ;
2 Supply it with building materials for growth and tissue repair;
3 Protect it against diseases.
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Importance of a balanced diet
The food and drink that a person normally consumes is called their diet. No
single food contains all of the chemicals needed by the body for good health. A
balanced mixture of foods from the different groups is needed to make up a
healthy diet. This should include at least five portions of fruit and vegetables
every day.
There are several deficiency diseases that can be prevented by eating a balanced
healthy diet.
Copy the table below into your jotter. Use the class resources to
research the link between diet and deficiency diseases. Use the
information to complete the table.
Vitamin Deficiency Disease Rich source of
Vitamin
A Night Blindness carrots
Scurvy (poor healing of wounds; soft bleeding gums)
D
B1
Mineral Result of serious deficiency of
mineral
Rich source of
mineral
Calcium
Milk
Anaemia (shortage of red blood cells)
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Importance of water
Water is critical to a number of functions in living organisms. It maintains
body temperature; plays a role in digestion; lubricates and cushions
organs; offers a moist environment to regions like the throat; transports
nutrients to the cells; and flushes toxins out of organs. It is also the final
product of respiration, in which the cells metabolize a viable source of
energy to power the activities of the body.
The Effect of radiation on Growth and Development of
Organisms
As well as diet having an influence on growth and development there are
many substances that organisms may be exposed to that can affect growth
and development.
Sometimes chromosomes can change if an organism is exposed to certain substances. These changes are called mutations and certain substances known as mutagenic agents can speed up the rate of mutations.
Mutagenic agents include radiation (X-rays, UV light from the sun) various chemicals and extreme temperatures.
Mutations can be harmful to organisms e.g. exposure to UV light from the sun increases the risk of skin cancer or they can be beneficial. In some crop plants extra sets of chromosomes gives the plant increased resistance to disease.
Write a paragraph in your jotter to summarise the information
above.
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The Effect of Chemicals on Growth and Development of
Organisms
Smoking and Health Risks
Smoking can affect the growth and development of organisms. Cigarette smoke contains carbon monoxide, nicotine and tar.
Nicotine is a mild stimulant found in tobacco plants, and can be smoked or chewed. Nicotine is an addictive drug which makes smokers crave cigarettes.
Carbon monoxide is a gas that has no taste or smell. However it is poisonous. In the blood stream is combines with the pigment present in red blood cells so that it can no longer pick up oxygen properly, therefore reducing the amount of oxygen available to the body through the bloodstream.
Tar contains many substances that can cause cancer.
Smoking during pregnancy slows down the growth of the unborn child.
The baby gets less oxygen than it needs because the mothers blood is polluted with carbon monoxide and is only carrying 90% of the oxygen that is should be taking to the baby.
Nicotine in the bloodstream reduces the amount of glucose that reaches the growing baby’s tissues.
On average babies born to mothers who smoke are lighter than those of non-smokers. Evidence also suggests that, on average, babies of nonsmokers grow up to be more intelligent than those of smokers.
1. Which gas present in cigarette smoke reduces the ability of the blood to
carry oxygen around the body?
2. What effect does nicotine have on the amount of glucose reaching a
growing baby’s tissues?
3. What effect does smoking while pregnant usually have on the on the birth
weight of a baby?
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The Effect of Chemicals on Growth and Development of
Organisms
Alcohol
Alcohol is also a poison to the body. Once
consumed it is absorbed from the stomach and
the gut and is carried around the body in the
blood stream. When it reaches the brain it
produces a stimulating effect on the nervous
system making people feel relaxed an
uninhibited.
Alcohol can be physiologically and psychologically addictive, with withdrawal
effects including delirium. Alcohol has a toxic effect on the liver, and also
effects the uptake of certain ions in the body.
In the short term excess alcohol leads to
Slower reaction times
Poorer muscle control and coordination
Poorer judgement
In the long term drinking alcohol to excess on a regular basis leads to
liver and brain damage.
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Alcohol
Excessive exposure to alcohol can cause damage an unborn baby at all stages of pregnancy. It can affect their development and lead to:
low birth weight
heart defects
learning and behavioural disorders
If alcohol severely damages the unborn baby’s brain, it may cause such problems as:
facial deformities
problems with physical and emotional development
poor memory or a short attention span
mental illnesses, such as alcohol or drug addiction
Key Questions (Answer in sentences)
1. By what means does alcohol get from the stomach to the brain and other
organs?
2. What effect does alcohol have on the drinker’s brain and liver?
3. List 3 effects alcohol has on the development of an unborn baby.
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The Effect of Chemicals on Growth and Development of
Organisms
Effects of Lead
Lead is a poison that can get into the air we breathe from car exhaust fumes
or into drinking water from lead pipes.
Lead can cause brain damage. The harmful effects of lead occur as a result
of its effect on an enzyme called catalase. This enzyme is responsible for the
breakdown of poisonous hydrogen peroxide which accumulates in the body
to oxygen and water.
Experiment 2:
Investigating the effect of lead on enzyme activity.
Collect the following apparatus
2 boiling tubes 2.5ml syringes wooden splint
test-tube rack 5% hydrogen peroxide solution fresh liver
scalpel 5% lead nitrate solution stop clock
distilled water balance goggles
10ml measuring cylinder
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Procedure
1. Set up the two boiling tubes as shown below and leave for 5
2. Add 5mls of hydrogen peroxide to each tube using a 10ml measuring
cylinder.
3. Observe each tube carefully to see what happens.
4. After a few minutes hold a glowing split inside the mouth of each
boiling tube. Observe what happens.
Now write a report on your experiment.
Remember to include:
An aim (what you were trying to find out)
The method (diagram included)
Your results (what you observed)
A conclusion
What was the purpose of tube B?