Seahorse reproduction

Is a seahorse a mammal or a fish? How does a seahorse reproduce?


The seahorse is a fish. Unlike most fish, it does not have scales. It has rectangular bony plates that cover its body. Seahorses do not have teeth and swallow their food whole with powerful suction through their snout. To hide from their predators, they grow long skin appendages so that they can blend in better among the algae and seaweeds.


Seahorse reproduction is unusual as the male is the one that becomes pregnant. During mating, the male and the female entwine their tails and the female connects a tube called an ovipositor to the male's pouch. After the eggs are moved into the male's pouch, the male will fertilise them. The fertilised eggs will hatch in the male's pouch.


The males are pregnant for several weeks before giving birth. When they prepare to give birth, the males undergo muscular contortions that last for about ten minutes. They will bend forward and backward. Then the brood leaves the male's pouch, one after another.




Watch this video that shows the male seahorse giving birth...

Watch another video that is downloaded from the Internet...

Voyage Night Festival 2011

Where can you take your child to today and on Tuesday when they do not need to go to school? Well, you can visit some museums in Singapore free. 

I attended the Night Festival organised by the National Museum of Singapore on 27 August (Saturday).   There were special events at the National Museum of Singapore, Singapore Art Museum, the Peranakan Museum and others. We took advantage of the free admission and visited the Peranakan Museum and the National Museum of Singapore. 

(A) Night Ride at Peranakan Museum

There were many families at the Peranakan Museum, a favourite among children. We learnt more about the Peranakans through the exhibits. There is one exhibit, the Sarong Kebaya exhibit, that captures the interest of many girls. Many of us were enthralled by the sand art performance by Ms Stacey Lee. The sand art performance was amazing! I recorded part of the performance.

Visitors to the Peranakan Museum could also watch a Chinese shadow puppet show or create sand and paper crafts.

(B) National Museum of Singapore

I viewed an exhibit, "Transforming Landscapes, Improving Lives: 50 years of Economic Development". The Economic Development Board (EDB) celebrates its 50th anniversary this year. Hence I thought it is timely for us to understand and reflect on our economic development through this exhibition.


If you are a photography lover, you would love the Abbas, 45 years in Photography exhibition. This exhibition showcases black and white photographs based on theme such as war, day-to-day life and religion. 


If you have missed the event, you can still visit most museums free within the month of August. On 2 September (Friday) and 3 September (Saturday), you can visit the National Museum of Singapore, Singapore Art Museum free from 6 p.m. to 2 a.m.


~ Serena's Greenhouse

Good Read - Charlotte's Web

Children will love this memorable story of Wilbur, a little pig who becomes famous with the help of his clever arachnid friend, Charlotte. Fern begs her father, Mr Arable, to raise Wilbur who struggles to survive. The Arables manage to nurse Wilbur to health. Wilbur moves to Zuckerman Farm where he learns the true meaning of friendship from the wise spider, Charlotte. When Charlotte and the rest find out that Wilbur is well fed for a reason, they are determined to foil Mr Zuckerman's plans. Determined to save her friend, Charlotte spins a web that reads "Some Pig", convincing Mr Zuckerman that Wilbur is no ordinary animal and should be saved. With the help of Charlotte and other friends, Wilbur wins a prize in the County Fair. 


This is a classic and beloved novel from E.B. White. It has won a few awards such as the Newbery Honour Book Award (1953) and Massachusetts Children's Book Award (1984). It touches on the themes of friendship and loyalty. It reminds kids that friends come in all shapes and sizes. Personally, I find the story very heart-warming and touching, especially the part where Wilbur finds out that Charlotte is dying. 


~ Serena's Greenhouse

Cool Science Gadget: Hand Boiler

During a Science lesson, one of my lovely pupils, Theresa, brought along a hand boiler. The class was excited. They found it cool.

Steps:

1. Hold the bottom bulb of the hand boiler in your hands and squeeze it.


2. Observe what happens.

Observation:

When you hold the bottom bulb of the hand boiler in your hands and squeeze it, you will see the liquid bubbling and it will go up to the top bulb.

Watch a video...

Challenge:

How do you get the liquid back to the bottom bulb of the boiler without turning it over?

Solution:

Hold the top bulb in your hands Or

Wait for the air in the bottom bulb to cool off

How does the hand boiler work?

Teacher Serena's Explanation:

The liquid in the hand boiler has a low boiling point. When we hold the bottom bulb in our hands, heat from our hands is transferred to the bulb and to the liquid and vapour above it. The vapour that sits above the liquid gains heat and expands. This additional warmth causes more liquid to evaporate.

This Science toy demonstrates the relationship between temperature and pressure. The hand boiler is a closed container. Therefore, as temperature goes up, the molecules of gas in the container move faster and this causes pressure to increase. As the pressure increases in the lower bulb, the liquid will be pushed up the tube into the top bulb. When the level of the liquid in the bottom tube falls below the end of the tube, vapour can travel up the tube and rise through the liquid, giving the appearance of boiling.

Conversely, as the air in one of the chambers cools off, the molecules of gas slow down, lowering the pressure. The liquid will move from an area of high pressure to an area of lower pressure.

~ Serena's Greenhouse

Science Misconceptions on States of Water

When we boil water, we see "white clouds" coming out of the spout of the kettle. What are the white clouds?

Misconception:
The "white clouds" are steam.

Correct concept:
The "white clouds" are condensed water droplets. They are formed when the steam meets the cooler air in the surroundings, lose heat and condense to form water droplets.
The "white clouds" are not steam. Steam is in the gaseous state and cannot be seen.

~ Serena's Greenhouse

Learning Prefixes

It is important for children to understand how a prefix or suffix can alter the meaning of a word. After they have gained a basic understanding, they can then connect new words to those words that they have learnt and that share a common prefix. 

Examples of common prefixes

Prefix                Meaning                                 Examples
un not; reversal of untrue, uncover

re                   again, back                                return, review

in                   in, into                                       insert
                      not                                             inedible

de                   opposite                                   defrost, dehydrate

sub                under                                        submarine

trans              across                                       transport, transmit

mis                   wrongly                                misjudge, misfire

~ Serena's Greenhouse

Video on Acids and Bases

What is the PH scale? Learn about acids and bases. Find out how they are measured and classified.

Click on the Heading to view the movie. At the end of the short movie, you can take an interactive quiz to see what you've learned.

Science Misconceptions on Respiration

Misconception (1):
Breathing is the same as respiration.

Right concept: 
Breathing is the exchange of gases between the air and our bodies. On the other hand, respiration is the process by which oxygen is used to break down food to provide our body with energy.

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Misconception (2):
Plants carry out respiration only at night.

Right concept: 

Plants carry out respiration all the time, even when they are photosynthesising.

~ Serena's Greenhouse

Science Misconceptions

Is breathing the same as respiration? Can we use the terms "respire" and "breathe" interchangeably?

Children have certain misconceptions about Science. As educators and parents, it is useful to know these misconceptions so that we can lead the kids in the discussion on these misconceptions. We can also gear our lessons or discussions towards clarifying these misconceptions.

I will be sharing some of these common misconceptions in this blog. You may want to test them out on your kid and see if he or she has these misconceptions too.

Good Read: The Giving Tree

Personally, I like this simple story and have shared this story with some of my pupils before. This story is about a relationship between a young boy and a tree. The tree loves the boy so much that she gives him everything that he asks, even to the point of allowing him to cut her down so that he can build a boat to sail away. When the boy becomes an old man, he returns and the tree tells him that she has nothing left to give him. The old man says that he just needs a place to sit down and rest. The tree which is now a stump obliges.

Readers have reacted to this book differently. Is the boy too selfish? Is the tree self-sacrificing? The interpretation is up to the reader as I do not think that the author meant to prescribe a moral lesson.

~ Serena's Greenhouse

Hitch a ride!

Symbiosis between zebra and oxpecker

Have you seen a bird perched on a zebra and wondered why the zebra is carrying it around?

The oxpecker hitches a ride from the zebra. In return, the oxpecker picks ticks and other insects from the zebra's body. The zebra benefits from this partnership as it manages to get rid of blood-sucking insects from its body. The oxpecker benefits from this partnership as it gets its food.

~ Serena's Greenhouse

Another PSLE Oral Exam Video

Here's another video on the PSLE Oral Exam prepared by Catholic High School (downloaded from Youtube).

PSLE Oral Exam Video

Watch the following video by Griffiths Primary School (downloaded from Youtube) to better prepare yourself for the PSLE Oral Exam.

PSLE Oral Examination Tips and Techniques - More Commonly Mispronounced Words

Here are more commonly mispronounced words. Have fun practising pronouncing these words before the PSLE Oral Examination.

market                  mahr-kit

mischievous         mis-chuh-vuhs

opportunity          op-er-tyoon-ni-tee

purchase              pur-chuhs

presentation         prez-uhn-tey-shuhn

restaurant             res-ter-uhnt

society                 suh-sahy-i-tee

souvenir              soo-vuh-neer

sword                  sawrd, sohrd

vehicle                vee-i-kuhl

won (past tense of win)   one

~ Serena's Greenhouse

PSLE Oral Exam Tips and Techniques - Commonly Mispronounced Words

How do you pronounce the word "athlete"? Is it a two-syllable or three-syllable word?

The PSLE Oral Examination is just round the corner. Here are some commonly mispronounced words. Spend some time looking through the list and pronouncing the words. When you are in doubt, use the phonetic symbols in dictionaries to learn the pronunciation. Alternatively, you can use an online dictionary to listen to the correct pronunciation.

Hint: Read the words with the appropriate stress

Examples of commonly mispronounced words:


apparatus           ap-uh-rat-uhs

calendar             kal-uhn-der

comfortable       kuhmf-tuh-buhl
chaos                 key-os
character           kar-ik-ter
children             chil-druhn

colleague          kol-eeg

demonstrate      dem-uhn-streyt

develop             dih-vel-uhp
film                   film   (not phi-lim)


All the best for the PSLE Oral Examination!

~ Serena's Greenhouse