Pregnancy and Delivery

Today, Dr Tan showed us a video on Pregnancy and Delivery. The video was about a woman going through her pregnancy. The video shows us different stages of the baby in the mother's womb. It also tells us that when the baby is about to be delivered, the head will be facing downwards towards the womb. However, there are some cases where the baby's head is not facing down. This is dangerous during delivery as the baby might die of suffocation in the mother's cervix. Also, the arms of the baby might also dislocate when delivering the baby. In most cases, the doctor will advise the mother to opt for cesarean section instead for the safety of the baby. After watching the video, i now know the hardship our mothers went through in giving birth to us. Dr Tan also shared his experience when his wife went through labour.

Reproduction in Man

In this topic, we learn about the changes we go through during puberty and about our sex organs. In male, the sex organ is called the penis, while in females, the sex organ is called vagina. In males, the testis produce the male hormones and male gametes which are also sperms. These sperms contain the genes of the male. In females, the ovary produces the female hormones and female gametes which are also called eggs or ova. These ova contain the female genes.

We also learn about the menstrual cycle. This cycle is when the uterus lining breaks down and disintegrate forming blood. Also, by looking at the timeline of the menstrual cycle, we know when the female is fertile and when she is not.

Colours of light

The first time i heard of this was when i was in kindergarten.All i knew about it was that there were 7 colours in the rainbow. But after learning about this, i now know that the colours on the rainbow are not place by random. It is placed by how much they refract. Also, i learnt that if shine a certain colour onto a coloured surface, different colours will give u different results. But it is not like if u shine red it will give u red that kind. It is of a different pattern.

Optics

In this topic, we learnt about lenses. we learnt about the different lenses and what are their uses. We also learnt about reflection and refraction. These two are completely two different things. For reflection, it means the light rays reflecting on a surface. The angle of incident and angle of reflection will be the same. For refraction it means the light rays passing from a less dense medium to a denser medium. The angle of incident will not be the same as the angle of refraction. Critical angle is something that we learnt. It is when the angle of refraction is 90 degrees. Thus the angle of incident will be the critical angle. We also learn about total internal reflection. It is when the incident ray is in the less denser medium. When the angle of incident is bigger than the critical angle, total internal reflection occurs.

Acids Bases and Salts.

In this topic, we learnt about the PH level of different acids and alkaline. For acids, the PH level will be below 7, while for alkaline, the PH level will be above 7. If the PH level is 7, it means neutralism has happened and the substance is water. Alkaline are also called bases. When a acid react with bases, it produces a salt and water. The acids we use in our laboratory are diluted acids but that does not mean that they are not corrosive. It may still be dangerous if these acids come in contact with us. In a strong acid, almost all the molecules are ionized in water. For weak acids, it is the opposite. Almost all the molecules are not ionized with only a few ionized.

After learning this topic, i relised that acids can be used in many ways and not only in labs. The experiments in the science lab were also fun when we used to litmus paper to check for the PH level of the acid or base.

Periodic Table

We learnt about this in secondary 1 but it was not as detailed as in sec2. In this topic, we learnt about how this table was created, the atomic mass and number. We also learnt that the elements are classified by their characteristics. For example, in group 1, all the elements are alkaline. Alkaline elements are shiny. For the second group is the halogens. They are combine with metal to produce salts. The third one is The Noble Gases.

After this topic, i learnt more about elements.

reflection after term test 3

Before this test, i was very nervous as i was not good in physics as compared to biology. Thus i started revision refraction and other physics stuff very early. In the end, it turned out that my physics did better than my biology ): After this, i now know that revising for only 1 topic for a test that is going to test 2 topics will not be effective even though u are confident in the other. Even though i got a1 for this test, i feel that i was really lucky and i should revised more on biology also.

Ecology

When i first heard that we are going to do this subject, i thought it would be similar to the kind that we learnt in primary school which is about the food chain and about which animals are prey and which animals are predator. But after learning it, i realised there were more than what i learnt in the past. At first, i did not understand what was going on as i was not good in this. But after lots of revision and practise, i finally understood the whole thing. As i didnt do well in ecology in the class test, i will try to improve on it so as to be ready by EOYs