Term 3 summary.

In term 3, I learned about unicellular and multi cellular organisms.. All living things are made of one or more cells. Living things with just one cell are called unicellular organisms. Examples of which are amoeba, Paramecium and yeast. Most living things are multi cellular and are bade up of more than one cell and are called multi cellular organisms.


I also learned about animal cells. Animal cells have cell membranes, vacuoles, cytoplasms, nucleus and chromosomes. Chromosomes are found in the nucleus and are made of DNA and proteins, and they contain genes which are passed down from generation to generation..

I also learnt about plant cells. Plant cells have a cellulose cell wall, a cell membrane, vacuoles, cytoplasm, nucleus and chloroplasts. Cellulose is a compound containing carbon, hydrogon and oxygen and is a type of fibre.

I also learned about the different shapes and functions of different cells like guard cells, nerve cells and red blood cells. In multicellular organisms, cells of the same type group together to perform the same job called tissues, for example nerve tissue, muscle tissue, and epithelial tissue. On the other hand, there are plant tissue such as vascular tissue, dermal tissue and ground tissue. Different tissues are usually grouped together to form an organ.

I also learned about osmosis. A water molecule is not very large. It consists of very smalls atoms. When osmosis occurs, a water molecule passes through a semi permeable membrane, leaving the water pure with other impurities left behind because they are too big to pass through the semi permeable membrane. I also learned the difference between an isotonic solution, hypotonic solution and a hypertonic solution, and the different effects of osmosis on the three solutions.


I also learned about how enzymes play a part in digestion, and the difference between chemical and physical digestion. I learned 4 different enzymes- Amylase, Maltase, Protease and Lipase. I also learned about the difference about the alimentary canal and the digestive system. I also learned the use of Pancreas juices and bile.


I also learned more about photosyntheses. Photosynthesis is the process by which plants use carbon dioxide use carbon dioxide, water and light trapped by chlorophyll to make food in the form of glucose, with oxygen given off. Photosynthesis takes place in chloroplasts and chlorophyll appears green because of green pigments in the chlorophyll. I also learned how to test for starch using iodine solution.


I also learned about respiration. There are 2 types of respiration, Aerobic and Anaerobic respiration. Aerobic respiration is the process whereby glucose is broken down in the presence of oxygen with the large release of energy in cells. Water and carbon dioxide are released as waster products.

Tissue respiration is the process where glucose is broken down in cells. A large amount of energy is released to perform different activities. Breathing is the process of bringing oxygen from the surrounding environments into the body. It also removes oxygen and carbon dioxide form the body. Most organisms respire aerobically. Energy is used for growth, muscle contractions, digestion and cell division.

The human respiratory system consists of the nose, nasal cavity, pharynx, trachea, bronchus, bronchioles, alveoli, diaphragm and lungs. Air enters and exits two external nostrils. Breathing is the physical process by which respiratory gases are exchanged with the surroundings. In inhalation/Inspiration, air is taken in from the surroundings while in exhalation/expiration, air is given out from the body. In inhaled air, there is more oxygen, less carbon dioxide and less water vapour than compared to exhaled air.


Overall, i enjoyed term 3 science as i learned a lot of new stuff about photosyntheses and respiration and osmosis. I hope that the rest of my science journey is as interesting as this years science topics.