PSLB | Cycles | Notes 2
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Primary Lower Block Cycles: Life Cycles Introduction to Notes 2
The worker bees clean the brood cells during the first few days of their adult lives.
They must also dispose of dead bees and larva in places away from the beehive.
They then become nurse bees who feed and care for the young.
From the 7th day, they tend to the queen bee whose only job is to lay eggs.
Wax-producing worker bees will need to eat 8kg of honey to produce 1kg of beeswax.
The beeswax produced appears through tiny pores in the bee’s abdomen and will need to be chewed on by the bees before it becomes soft enough to be used to repair and build more honeycomb cells.
We know children like comics! Using that to our advantage, we introduce complicated concepts in a fun way.
PSLB | Cycles | Notes 2
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Later, the young worker bees pack and store pollen and nectar brought home by the older foraging bees so that they can be used as food for the rest of the colony.
They also help to keep the hive cool by fanning it with their wings using water brought home by the water-carrying bees.
* The above pictorial representations of the honey bees are for the purpose of providing information about their activities only. Please find realistic illustrations of the bees on the next page.
The guard bees station themselves near the entrance to the hive and stand guard, letting only family members into the hive.
The worker bees finally ‘graduate’ from being house bees after 21 days. They are now foraging bees and will leave the hive to gather pollen and nectar.
PSLB | Cycles | Notes 2
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In today’s lesson, you will learn to:
describe the four-stage life cycle of a/an:
ladybird beetle
mosquito
butterfly
ant
queen bee worker bee drone bee
Different Types of Honey Bees
There are three types of honey bees.
The queen bee’s only job is to lay eggs. There is only one queen bee in each honey bee colony.
The second type of honey bees are the male drones and their job is to mate with queen bees from other colonies. There may be several hundred drones in a colony.
The worker bees are the third type of honey bees. All the worker bees in a colony are female and they are responsible for all the tasks in a beehive except laying eggs. The worker bees perform several jobs one after another during their lifetime. The youngest worker bees take care of the young and the queen. They then become housekeepers and storekeepers. The older worker bees become the guards to the hive and finally, the oldest worker bees become gatherers which bring nectar and pollen back from outside the hive. There are about 20 000 to 80 000 worker bees in a colony.
PSLB | Cycles | Notes 2
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RECAPITULATION A cycle is a pattern that repeats itself continuously.
A life cycle is a pattern that repeats the stages of development in the lives of the
living things.
Metamorphosis refers to the big changes in the form and habits of an animal from
birth to adult.
Animals which undergo complete metamorphosis have young that look very
different from the adult.
Example: Insects that undergo a four-stage life cycle: butterfly, ladybird beetle
Animals which undergo incomplete metamorphosis have young that look similar
to the adult.
Example: Insects that undergo a three-stage life cycle: grasshopper, cockroach
Primary Lower Block Cycles: Life Cycles Notes 2
adult
egg
larva 4 stages in the life cycle of an
insect
pupa
adult
3 stages in the life cycle of an
insect
egg
nymph
PSLB | Cycles | Notes 2
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FOUR-STAGE LIFE CYCLES CASE STUDY A
Life cycle of a ladybird BEETLE
The female ladybird beetle lays its eggs on the underside of leaves.
The eggs resemble tiny yellow jellybeans.
The larva feeds on aphids, mites and even other ladybird beetle eggs.
It grows rapidly and when its body grows too big for its skin, a new skin grows
beneath the old one.
The process by which the old skin is shed is known as moulting.
The insect attaches itself to a leaf during the pupal stage.
During this stage, the pupa does not feed and there is very little movement. However,
the adult structures develop within it.
The adult beetle emerges after about a week.
The cycle repeats when the female ladybird beetle reproduces.
larva
3 weeks to a month
pupa
About 1 week
About 1 week
egg
adult beetle (2 – 3 months)
The tiny yellow eggs are laid on the underside of leaves.
1
The larva feeds and grows rapidly.
2
The pupa does not feed while its adult structures develop.
3
The adult ladybird beetle emerges after a week.
4
Visuals help our students to grasp the concepts quickly.
PSLB | Cycles | Notes 2
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we cannot be showing you the best.
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PSLB | Cycles | Notes 2
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Do drop by our centre to view the full set of materials.
PSLB | Cycles | Notes 2
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The monarch butterfly
The Monarch Butterfly is also known as “Milkweed Butterfly”. The Monarch butterfly only lays its eggs on the milkweed plant because its caterpillar only eats
the leaves from the milkweed plant. The Monarch butterfly is poisonous and distasteful to birds and mammals. It is thought that the bright colours of the larva and adult function as warning colours.
CASE STUDY D
Life cycle of OTHER INSECTS
Number of stages Organisms
3-stage life cycle
Cricket – lays eggs in warm damp soil
Dragonfly – lays eggs in water
4-stage life cycle
Bee – lays eggs within the cells in the hive
Mealworm beetle – lays eggs on leaves
cricket nymph
mealworm beetle larva
PSLB | Cycles | Notes 2
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The Silkworm A silkworm is the caterpillar of the silkworm moth of the mulberry tree. They were domesticated from the wild silkworms about 2000 years ago! They are bred for the
production of raw silk. In the pupa phase, the silkworms enclose themselves in cocoons made up of raw silk produced by their salivary glands. The silkworm pupae are then boiled and killed. If the moths were allowed to emerge from the cocoon, the silk will be destroyed as the moths produce enzymes that will damage the silk.
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PSLB | Cycles | Notes 2
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Summary 1. A butterfly’s egg will hatch into a l____________ which is also known as a
c_____________________.
2. A l____________ will develop into a p____________ before it turns into an adult.
3. A mosquito l____________ is also known as a w____________.
4. A mosquito w_______________ breathes through a b___________________
t____________.
5. The process whereby the old skin is replaced by the new skin is known as
m___________________.
6. During the p____________ stage of an insect, it does not feed at all while the adult
structures are developing within it.
Summarising the chapter helps our students to recap what has been taught during the lesson!
PSLB | Cycles | Practice 2
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Primary Lower Block Cycles: Life Cycles Practice 2
Our notes are complemented by a comprehensive Practice paper.
A typical practice will have 15 multiple-choice questions and 5 open-ended questions for our students to attempt. This is then followed by an ‘ACE’ question to further enhance the understanding of our students. This proprietary technique is uniquely found at JustEdu and has helped numerous students to break down and analyse the question before attempting. Furthermore, this same technique can be used to answer multiple-choice questions as well. An example of an ‘ACE’ question is given next:
PSLB | Cycles | Practice 2
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Use the ACE Question Answering Technique to answer the question below.
Karine placed an egg of an insect together with some food and water into a sealed container that had some holes in its lid. After some time, she observed that the young that had hatched from the egg did not feed or drink for a period of about a week. However, the insect could still develop into a healthy adult. (a) Give an example of an insect that Karine could have kept in her tank.
(b) Explain your answer in part (a).
Circle the important information in the question above. Study the question and write down in the space below the information that you can obtain from the question.
Topic: ________________________________________________________________ (a) and (b) Concepts:
The young of an insect does not _______________ or drink during the
_______________ stage.
The _____________-stage life cycle of an insect includes the egg, _______________,
_______________ and adult stages.
Insects such as the _______________, ______________ and _______________
undergo a four-stage life cycle.
(b) Key points: _________________________________________________________
_________________________________________________________
STEP 1: ANALYSE THE QUESTION
STEP 2: CONCEPT ANCHORING
PSLB | Cycles | Practice 2
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Link the requirements in the question with the keywords listed above. You may use arrows or a simple concept map to help you.
Answers:
(a) Give an example of an insect that Karine could have kept in her tank.
___________________________________________________________________ (b) Explain your answer in part (a).
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
STEP 3: ESTABLISH RELATIONSHIPS AND LINKAGES
PSLB | Cycles | Practice 2
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Use the ACE Question Answering Technique to answer the question below.
Karine placed an egg of an insect together with some food and water into a sealed container that had some holes in its lid. After some time, she observed that the young that had hatched from the egg did not feed or drink for a period of about a week. However, the insect could still develop into a healthy adult. (a) Give an example of an insect that Karine could have kept in her tank.
(b) Explain your answer in part (a).
The insect young was provided with air, food and water.
Topic: ________________________________________________________________ (a) and (b) Concepts:
The young of an insect does not _______________ or drink during the
_______________ stage.
The _____________-stage life cycle of an insect includes the egg, _______________,
_______________ and adult stages.
Insects such as the ________________________, ______________ and
_______________ undergo a four-stage life cycle.
(b) Key points: _________________________________________________________
_________________________________________________________
STEP 1: ANALYSE THE QUESTION
STEP 2: CONCEPT ANCHORING
Answers
Life Cycles
feed
pupa
four larva
pupa
ladybird beetle
housefly
butterfly
Four stage life cycle, young in the pupa stage
does not feed or drink.
PSLB | Cycles | Practice 2
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Link the requirements in the question with the keywords listed above. You may use arrows or a simple concept map to help you.
Answers:
(a) Give an example of an insect that Karine could have kept in her tank.
___________________________________________________________________ (b) Explain your answer in part (a).
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
STEP 3: ESTABLISH RELATIONSHIPS AND LINKAGES
The pupa does not feed or drink in this stage
Four-stage life cycle of an insect
Includes
butterfly / housefly / ladybird beetle
example
Egg stage
Larva stage
Pupa stage
Adult stage
Butterfly / housefly / ladybird beetle (any one)
The butterfly / housefly / ladybird beetle undergoes a four-stage life cycle which includes a pupa stage. The insect does not feed or drink during the pupa stage.
Answers
PSLB | Cycles | Concept Map (for student’s reference only)
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Animals
4 stages
Butterfly
Housefly
Mosquito
Egg
Larva Adult
Pupa
3 stages
Chicken
Cockroach Grasshopper
A pattern that repeats itself to show the stages of development of a living thing
Egg
Young Adult
Flowering Plants
3 stages
Tomatoes
Seed
Young plant
Adult plant
Life Cycles
Primary Lower Block | Cycles: Life Cycles | Concept Map
At the end of each topic, students are equipped with a concept map and a list of keywords and phrases to reinforce the key concepts of the topic.
PSLB | Cycles | Concept Map (for student’s reference only)
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List of Keywords and phrases
growth
incubation
larva
nymph
outer covering of an animal is replaced through the process of moulting
pupa
reproduction
seed leaves
vegetative propagation
warmth, oxygen and water are needed for germination
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