Something SHY

We know how copulation can result in pregnancy. However, in modern day society, many people are not only seeking for their pursuits and also the increasing cost of child raising in developing countries. As a result, birth control methods are introduced.There are 2 types of birth control methods, the temporary birth control and the permanent birth control. For temporary birth control, once its removed, a couple can get pregnant again. However, permanent birth control is irreversible. Such examples are vasectomy and tubal ligation. Vasectomy is the cutting and tying up of the sperm ducts to prevent sperms being ejaculated from the epididymis. Tubal ligation is the cutting and tying up of the fallopian tubes. In this way, no ovum can reach the uterus for implantation and no sperm can reach the ovum. The temporary methods includes rhythm, condom, withdrawal, Pill, diaphragm, IUD. Just to name a few. Being the most common, the condom. It is latex fitted over the penis of the man to hold the sperms after ejaculation. The diaphragm also acts in the same way, but being fitted on the cervix by a doctor. The IUD, being much rarer is "The intrauterine device (IUD) is a form of birth control; it is an object, placed in the uterus, to prevent pregnancy.[1] Among modern IUDs, the two types available are copper-containing devices, and a hormone-containing device that releases a progestogen." From WIKI.

Some expectations for Term 3

With the start of the new term tmr, I am looking forward the the science lesson. It's going to be whole new topic on biology, with a tinge of physice which I hope I can manage well this time. Again, I have set my target for my science test to be at 37 and or above. I have also devised a plan where I will revise the lessons learnt after each science lesson lesson! Hope this helps, The next time I post will be the results and reflections. Work Hard :)

CARBON CYCLE

Actually I've always believed that carbon, which can also exists as carbon dioxide is bad for the environment. Yes, its true but after my self-learning through ecology(P.S I did this during the hols), the carbon cycle is THE ROOT TO ALL LIFE. This simple cycle ensures that carbon dioxide in the air is always kept constant, not too much, nor too little. During photosynthesis, plants take in carbon dioxide and give out oxygen. The carbon dioxide is turned into complex materials such as sugars, amino acids and stores energy. When the plant is eaten by the autotrophs on the next tropic level, the energy stored in the carbon is passed on to it. The autotrophs releases carbon back to the atmosphere when they are respiring. The feces and animal waste also contains the ingested carbon. Decomposer such as fungi and bacteria feed on them. When the bacteria and fungi respires, carbon dioxide is again released into the atmosphere. When organisms die, decomposition occurs and the same process goes on. By chance, the dead organisms can become fossil fuels or coals. They store tremendous amounts of carbon energy and it is released via combustion. Large amounts of carbon dioxide are released back into the atmosphere. Luckily, the plants take in more carbon dioxide compared to its intake of oxygen and this prevents the level of carbon from getting to high. THE 3 PROCESS THAT IS ESSENTIAL FOR RELEASE OF CARBON IS RESPIRATION, COMBUSTION and DECOMPOSITION. The carbon cycle is important as it transfers energy from one organisms to another as energy are locked up in the carbon. It also ensures that there is enough carbon dioxide in the air for the plants to photosynthesis and ensures that ecosystem, food chain and webs are disrupted. YAY! So next time you are respiring, remember that U are part of the cycle TOO!

Female Reproductive System

The female reproductive system is a little more complex than that of the male's. This includes the menstrual cycle.

The female gonads are the ovaries. They produce female gametes which are known as eggs or ova. The ovaries contains thousands of eggs but only about 400- 500 become mature in a woman's life. The ovary stops releasing eggs when the woman reaches about 50. This is known as menopause. The ovaries also produce female hormones such as oestrogen and progesterone. The fallopian tubes/oviducts is where fertilization occurs. The uterus/ womb is where the fertilized embryo further develops into a baby. The cervix is expands during childbirth. The vagina is a passage linking the vulva to the cervix. A man's penis enters the vagina during sexual intercourse and deposit sperms there. The sperms can them swim up to the fallopian tube where fertilization occurs.
The Menstrual Cycle

The menstrual cycle usually lasts about 28 days. The first day of menstruation is also the first day of the menstrual cycle. Before we go into this we need to look at the maturation of the eggs in the ovaries. The ovaries contains thousands of eggs or also known as primary follicles. Each month, only one will become mature. The mature egg is known as Graafian Follicle. They will be released from the ovaries and this is known as ovulation.After ovulation, the graafian follicle develops into Corpus Luteum .On the first five days of the menstrual cycle, the uterus lining breaks down.The wastes and bloods are discharged from the uterus in the body through the vagina. The anterior pituitary glands secretes follicle stimulation hormones (FSH). The FSH stimulates the maturation of the hormones. It also stimulates the follicles to secrete oestrogen. From day 6 to 13, the oestrogen helps the uterine lining to recover and build up again. An excess of oestrogen will stop the secretion of FSH w=and prevents more follicles from maturing. The oestrogen makes the pituitary gland secrete LH. The LH allows the graffian follicle to become corpus luteum. The corpus luteum secretes progesterone which helps to maintain the uterus lining for a number of days. If no fertilization occurs, it gradually breaks down.

Reproduction in Humans -- SELF STUDY IN THE JUNE HOLS

When we reach the age of 12-15 we boys start to notice changes in our body. Our reproductive organs get larger. Today, I will be reflecting on what I had learnt about the male reproductive system.
We
We will start with the testes. The male reproductive system contains two ovules of testes. They produces sperms. The epididymis stores inactive sperms before they are released into the sperm duct. The sperm duct loops over the ureter and opens into the urethra. The Prostate glands, Cowper glands and seminal vesicles releases fluids that contains nutrients and mixes them with the sperms before it is released from the urethra in the penis. This fluid actually activates the sperms. The mixture of sperms and the fluid is called semen.

Anatomy of a Sperm



The head of the sperm contains the nucleus, cell membrane and the acrosome. The acrosome is important as it contains enzymes to break through the cell wall of the female egg cell. The mitochondria produces energy for the sperm to swim to swim towards the egg to fertilise it. The tail or also known as flagellum allows the sperm to swim to the egg cell.

Term 2 Class Test + Reflections

I scored 29 out of 37 in this term's class test. It's a A1, but.... its LOW. I found that I did not revise thoroughly enough. My weaker areas are in Light and chemical equations. Although I spent a lot of effort trying to comprehend and understand how to draw the ray diagrams, I still didn't do well. I also didn't go through the combustion equations and I lost one mark :( I feel that I have troubles answering the light questions and drawing ray diagrams. Majority of the class did very well so I think its time for me to push myself even harder so I could strive for the better in the Term 3 Science Test which is focusing on Biology. With the help of my friends which specializes in Biology, I hope i can score an 80++ in the next test. HERE I COME :)

I also devised a plan and a motto for myself:
Never GIVE UP :)

Quartz Watch

Many of us have heard about quartz crystals keeping time accurate but I was wondering what exactly do these quartz do to keep the watch to maintain its staggering precision?

LET'S START!
Video;
http://www.youtube.com/watch?v=1pM6uD8nePo

Quartz Basic:Quartz is the most common mineral found on Earth. They are transparent or can be known as "crystals" which your mom wears as jewellery since they are nice, attractive and shiny!

Before Quartz
The wind-up watch is an amazing piece of technology itself! It is part of a continuous research-and-development effort that started at the end of the 14th Century. Over the years, different innovations made wind-up watches smaller, thinner, more reliable, more accurate and even self-winding!

The components that you find in today's wind-up watches have been around for centuries:

1)A spring to provide the power
2)Some sort of oscillating mass to provide a timebase
3)Two or more hands
4)An enumerated dial on the face of the watch
5)Gears to slow down from the ticking rate of the oscillating mass and connect the mass and spring to the hands on the dial

Then came the quartz....

There was no problem with the choice of a timing element. The quartz crystal is possibly thousands of times better for timing than the tuning fork, and quartz crystals had been around for many thousands of years. Only the type and the frequency of the crystal needed to be chosen. The difficulty was in the selection of the integrated circuit technology that would function at sufficiently low power.

Quartz crystals have been in regular use for many years to give an accurate frequency for all radio transmitters, radio receivers and computers. Their accuracy comes from an amazing set of coincidences: Quartz -- which is silicon dioxide like most sand -- is unaffected by most solvents and remains crystalline to hundreds of degrees Fahrenheit. The property that makes it an electronic miracle is the fact that, when compressed or bent, it generates a charge or voltage on its surface.(this is why the clock is so accurate!) This is a fairly common phenomenon called the Piezoelectric effect. The electronics of the watch initially amplifies noise at the crystal frequency. This builds or regenerates into oscillation -- it starts the crystal ringing. The output of the watch crystal oscillator is then converted to pulses suitable for the digital circuits, which sends the clock ticking!

In Conclusion:
It works by using the piezoelectric effect: if a small voltage is applied to a specially prepared crystal of quartz it vibrates at a definite and almost constant frequency which can be used to power a tiny motor to turn the hands of the watch.

Read more: http://wiki.answers.com/Q/How_does_a_quartz_watch_work#ixzz1GODFJHzq