Khamis, 8 Disember 2011

Plants Reproduce

Plants reproduce to ensure the survival of their species. They reproduce in many different ways.

1. Plants reproduce from seed.
    For example, a papaya plant.





The flowers will become fruits that contain seeds in them. When these seeds are planted, they will grow into seedlings and then into young plants.
Tomata, sun flower, balsam and shorea are reproduce from seeds.


                               sun flower     
                                  balsam plant


2. Some plants reprodece from spores. Ferns and mushrooms prodece millions of tiny spores. These spores can be easily carried away by the wind. They can grow into young plants under the right conditions.



When spores land on a moist place where there is food, they will germinate to produce a new plant.

                   bread with mould

3. Bryophyllum and begonia plants reproduce from leaves.



4. Tapioca, hibiscus and rose plants reproduce from stem cuttings.




5. Ginger, potato and onion plants reproduce from underground stems.




   On the surface of such underground stems, there are buds. Such buds can grow into new plants.The picture below shows the potato with buds.

potato with buds

6. Banana, pineapple and bamboo plants reproduce from sucker.

                                           banana tree  



Isnin, 5 Disember 2011

A Complete Change

A Complete Change

A Complete Change
Many young animals do not look like their parents. They undergo changes before they look like their parents. Can you name the animals?

The Life Cycle of A Butterfly
As advanced insects, butterflies and moths have a "complete" life cycle. This means that there are four separate stages, each of which looks completely different and serves a different purpose in the life of the insect.
1.     Egg   - The egg is a tiny, round, oval, or cylindrical object, usually with fine ribs and other microscopic structures. The female attaches the egg to leaves, stems, or other objects, usually on or near the intended caterpillar food.

2.     Caterpillar  - The caterpillar (or larva) is the long, worm-like stage of the butterfly or moth. It often has an interesting pattern of stripes or patches, and it may have spine-like hairs. It is the feeding and growth stage. As it grows, it sheds its skin four or more times so as to enclose its rapidly growing body.

3.       Pupa - The chrysalis (or pupa) is the transformation stage within which the caterpillar tissues are broken down and the adult insect's structures are formed. The chrysalis of most species is brown or green and blends into the background. Many species overwinter in this stage.

4.       Butterfly - The adult (or imago) is colorful butterfly or moth usually seen. It is the reproductive and mobile stage for the species. The adults undergo courtship, mating, and egg-laying. The adult butterfly or moth is also the stage that migrates or colonizes new habitats. The butterfly pictured here is a Monarch, which is fairly large in size. The Monarch's wingspan is 3 3/8 - 4 7/8 inches (8.6 - 12.4 cm).

What are the stages of the frog's life cycle?

Eggs:  Frogs lay thousands of eggs that do not have shells.  They are
covered with a jelly-like substance that helps protect them from being
eaten by creatures in the water.  The eggs stick together to form frog-
spawn that floats to the top of the water.  A few days later the tadpoles
hatch out.

TadpolesTadpoles have a head, tail and body.  They live under water
and breathe through their gills.  They eat algae and other tiny water
plants as they swim.  After about a month, a bulge appears at the
base of their tail where their hind legs will grow.  They also begin
to grow lungs for breathing.

Tadpoles to Froglets:  After seven weeks their hind legs begin to grow.  After nine weeks, front lets grow and their tails are almost gone.  After about twelve weeks the tadpoles can swim to the surface of the water and breathe in air
Adult Frogs:  After about three months, the tadpoles have become young frogs.  They can live in or out of water and eat insects or worms. 


Animals Live In Group

Animals Live In Group
1.       Why do some animals live in groups?
l  Some animals live in groups for protection
l  Some animals live in groups in order to search for food
2.       Some animals live together for protection
l  Fish swim together in schools to warn each other of approaching danger.
l  Baboons move together in a troop
l  Gazelles live together in a group called a harem
3.       Some animals live in specialized groups called colonies.
i)                     In a colony each animal has a specific job.
ii)                   Animals in a colony communicate in a unique way
iii)                 Bees live in a colony called a hive.
iv)                 A hive has one queen bee.
v)                  The worker bees search for pollen
vi)                 Honeybees communicate the location of food by doing a dance.

4.       What do you know about animal groups?
What do you call…
          a group of kangaroos?           
          a group of foxes?        
          a group of monkeys?

5.       What animals live in family groups?
          Animals that live in family groups are Lions, Dolphins, Orcas, Wolves, Buffalo, Elephants, Hyena, Primates, monkeys, most lemurs, apes (except orang-utans), wolves, dingoes, African wild dogs, lions, hyenas, most deer and antelope species, horses, rats, buffalo, bison, ants, bees, termites and numerous species of bird and fish.

Science Year 6 : Food Preservation

Food Spoilage

1. Food can spoil after a certain period of time.
2. Spoilt food will change in texture and taste.
3. One can get food poisoning by eating spoilt food.
    a) Food poisoning can lead to stomach upset, diarrhea and vomiting.
    b) Serious food poisoning may cause death.
4. Foods which are spoilt can be identified by observing, touching, smelling and tasting.
5. Spoilt food has one or more of the following characteristics.
    a) Unpleasant smell
    b) Unpleasant taste
    c) Changed colour
    d) Changed texture
    e) Mouldy

Food Preservation
1.    Food preservation is a process that makes food last longer.
2.    Food preservation can prevent or slow down the action of bacteria or fungi on
    the food.
3.    There are many methods to preserve food.
    *   Drying
    *   Boiling
    *   Cooling
    *   Vaccum packing
    *   Pickling
    *   Freezing
    *   Bottling & Canning
    *   Salting
    *   Smoking
    *   Pasteurising
    *   Waxing

1. Food can also be preserved with salt. This process is called salting.
2. Salting can be done in two ways as shown below.
    a) Adding a lot of salt to the food.
    b) Soaking the food in a salt solution.
3. Bacteria and fungi cannot grow in salty conditions. Hence, salted foods last longer.
4. Examples of food that can be preserved by salting are fish, meat,   

    eggs, vegetable and fruits.
5. Salting will change the taste, colour and destroy food nutrition.

1. Pasteurising is a process in which milk is heated at 63 °C for 30 minutes or heated  
    at 72 °C fo 15 seconds and followed by rapid cooling to below 10 °C.
2. The pasteurised milk can then be refrigerated to last a few days.
3. Friut juice can also be preserved in this way.
4. This method of preservation retains the natural flavour of milk. Nutriens like vitamins

    are not destroyed.

Canning/ Bottling
1. Some foods can be canned and bottled. The canning and bottling of food allows the food to be kept for a very long time.
2. These methods of preservation involve:
    a) heating of the food to a very high temperature - can kill bacteria and fungi
    b) keeping foods in airtight cans or bottles - to prevent the entry of air that may    
        contain bacteria and fungi
3. Therefore, canned or bottled foods can be kept for a long time in months or years.
4. Examples of food that can be perserved by canning or bottling are shown below.
·         fish
·         meat
·         beans
·         corn
·         mushroom
·         chicken
·         pineapple
·         condensed milk
·         jam
·         soft drink
·         soy sauce
·         syrup
·         tomato sauce
·         fruit juice

1.   Boiled foods may last longer than unboiled foods.
2. When food is boiled, all bacteria and fungi will be killed.

1. We can dry food to remove water from the food.
2. Without water in food, bacteria and fungi cannot grow. This can make the food last  
3. Drying foods can be done as follows.
a) Drying the food under hot sun
b) Heating food to a high temperature
4. The disadvantage of this method is that the food becomes less nutritious because
    some nutrition may be lost during the process.