This is class 107's biology blog. Please refrain from using inappropriate terms. Instead, use proper ENGLISH.

Tuesday, January 26, 2010

Eyes Without a Face: Stem Cell Research

1. Case Study: Students to read an article ‘Eyes without a Face – Stem cell research and corneal implants’, and prepare a group consultation (5-6 students per group) involving discussion of the following topics and the possible conclusion to the case:

a. Stem cell function: differentiate adult and embryonic

b. Corneal-limbus stem cells — their function and use in transplants

c. Amniotic membrane use in cornea transplantation

d. Cornea transplant success and failure

e. Concerns with stem cell use in cornea transplants

2. Students will conduct online research to find out the possible outcome of the case study. Groups are to post their findings and conclusion in the Health Science blog & each student is to reflect the learning point from the other group.

Friday, January 22, 2010

DNA Assignment

Create a Keynote presentation to demonstrate understanding of DNA and its applications in benefiting human life (maximum 5 slides).


Slide 1: History of DNA research

Slide 2 & 3: Basic DNA structures

Slide 4 & 5: Uses in technology (applications) E.g., Genetic engineering, Forensics, DNA nanotechnology, etc.

Deadline: 26th Jan, Tuesday (by 8am)

1. Include all your group members' names in Keynote slide 1
2. Update your 3 IPW articles by 25th Jan, Monday (12pm)

5 Kingdoms of Living Things

Please visit the website for information on the 5 kingdoms of living things.

1. Kingdom Monera
2. Kingdom Protista
3. Kingdom Fungi
4. Kingdom Plantae
5. Kingdom Animalia

Wednesday, January 20, 2010

DNA Extraction at HOME!

Episode 1: Introduction to DNA

Episode 2: Extracting Strawberry DNA at HOME!

Mr. Low

Sunday, January 17, 2010

Microscope: Use and Care

Please watch this video before Tuesday (19 Jan 2010) practical lesson at the Biology Lab (Level 1).

Mr. Low

Interactive Websites for Learning (Animal & Plant Cell)

1. CELLS alive! represents 30 years of capturing film and computer-enhanced images of living cells andorganisms for education and medical research.

CELLS alive! Interactive Animal and Plant Cell:

2. is a web site for educational learning and having fun at the same time.

Interactive Game on Cell Organelles:

Mr. Low

Friday, January 15, 2010

IPW Homework Deadline

iProject Instructions

1. Please kindly access all iProject documents (My Preliminary Ideas Form, Sample PI & Literature Review Form) from this link: This will be the Official iProject website. Bookmark!
Note: Login before accessing the site.

2. Kindly send your completed documents (e.g., 1 PI Form & 3 Review Forms) to iProject class 107 sharing folder by next Monday
(18 Jan), 12pm. You have already learnt how to execute this task during your previous ICT lesson on Wed (e.g., drag & put in the sharing folder).


Tuesday, January 12, 2010

Root Hair Cell

Picture of a root hair cell in the soil ^

There are 5 organelles found in a root hair cell. They are the: nucleus, cytoplasm, plasma membrane, cell wall and vacuole. The root hair cell has a large surface area but is a delicate structure which can live up to 2 to 3 weeks. New root hair cells are formed at the top of the root to enable root hair coverage to be same. Root hair cells varies in length and diameter, from 5 - 17 micrometers in diameter and from 80 to 1500 micrometers in length. The root hair cells enable water to be absorbed by the plant through a thin root-like structure protruding out of the cell.

The nucleus contains chromatin material, consisting of the DNA of the cell which is important inherited by the daughter cells. The cell wall is a strong surface, surrounding the plasma membrane, which protects the cell and give it its shape. It also prevents too much expansion when water enters the cell. The plasma membrane controls the movement of substance into and out of the cell and is used for cell identification. The vacuole helps in isolating materials that pose as a threat to the cell and also helps in exporting waste products from the cell. The cytoplasm consists of cytosol and the cellular organelles, except the nucleus. The cytosol is made up of water, salts and organic molecules and many enzymes that speed up reactions. It is important as it suspends the cell organelles within it.

Picture 1:
Picture 2:
Information gathered from: ; ; ;

Done by: Lim Hao Yang, Neo Wei Hong, Wen Yue, Elgin Patt and Sean Phua

Specialised Cells Research

1. Students (in groups) to research on one of the following cells (e.g., root hair cell, green leaf cell, human muscle cell and human red blood cell).

2. Each student is to reflect the Learning Points of the other cell type (e.g., red blood cell group to reflect on root hair cell group). Please input your Learning Points in the comments by tonight (12 Jan 2010), 2359.

Area of focus:

a. What are the organelles found in the cell?

b. List the structural features of the cell.

c. What are the functions of these organelles?

d. Why are these functions of the organelles important to the living cell?

Green Plant Cells

What are the organelles found in the cell?
Ans: vacuole, cell wall, plasmondesma, chloroplasts, nucleus, cell membrane

List the structural features of the cells.
Ans: Plant cells have a special structure called cell wall that help it support itself and give its shape. The cell also contain chloroplast that help it make food by absorbing sunlight, with carbon dioxide (CO2) and water, a simple sugar called glucose is made.

What are the functions of these organelles?
Ans:cell membrane - the thin layer of protein and fat that surrounds the cell, but is inside the cell wall. The cell membrane is semipermeable, allowing some substances to pass into the cell and blocking others.
cell wall - a thick, rigid membrane that surrounds a plant cell. This layer of cellulose fiber gives the cell most of its support and structure. The cell wall also bonds with other cell walls to form the structure of the plant.
chlorophyll - chlorophyll is a molecule that can use light energy from sunlight to turn water and carbon dioxide gas into sugar and oxygen. (this process is called photosynthesis). Chlorophyll is magnesium based and is usually green.
chloroplast - an elongated or disc-shaped organelle containing chlorophyll. Photosynthesis (in which energy from sunlight is converted into chemical energy - food) takes place in the chloroplasts.
nucleus - spherical body containing many organelles, including the nucleolus. The nucleus controls many of the functions of the cell (by controlling protein synthesis) and contains DNA (in chromosomes). The nucleus is surrounded by the nuclear membrane
vacuole - a large, membrane-bound space within a plant cell that is filled with fluid. Most plant cells have a single vacuole that takes up much of the cell. It helps maintain the shape of the cell.
Plasmodesmata (singular: plasmodesma) are microscopic channels which traverse the cell walls of plant cells
Why are the functions of organelles important to the living cell?

Ans:The organelles work together to help the cell grow and reproduce.

With special thanks to : &

The names of the people who helped: hong kai xuan, elgin low, darius low, sun jie min, yeo jun jie, marcus au

Red Blood Cells

1.What the organelles found in the cell?
The organelles found in the red blood cell are the cytoplasm, which is rich in haemoglobin, a complex, metalloprotein and the cell membrane.
Red Blood Cells

2.List the structural features of the cells.
Without the nucleus in the red blood cell, it can carry more oxygen to other parts of the human body. It would not need the nucleus as the red blood cell flows through the blood, and not move on its own.

3.What are the functions of these organelles?
They aid by holding the oxygen carried in the red blood cell.

4. Why are these functions of the organelles important to the living cell?
The haemogoblin in the cytoplasm helps to bind the oxygen and release them throughout the body. Due to this, we would not have any difficulty breathing or suffocate to death.


Source: in-the-bloo/

Human muscle cells

2. List the structural features of the human muscle cells.

Muscle is composed of thousands of muscle fibers, each composed of a single muscle cell. A muscle cell contains a series of ultramicroscopic filaments called myofibrils. Each myofibril is a muscle cell that contains units called sarcomeres. Sarcomeres contain thick microfilaments composed of the protein myosin. Sarcomeres also contain thin microfilaments composed of the protein actin. The actin and myosin filaments are arranged parallel to one another, with the myosin filaments' molecular “heads” protruding toward the actin filaments. In skeletal muscle, the overlapping actin and myosin filaments give the muscle fiber a banded, or striated, appearance. Hence the muscle is striated muscle.

The human body has three major types of muscle. The striated muscle is given its name because of its fibers' overlapping actin and myosin filaments, giving it a banded appearance . This muscle is found in the limbs and is also called skeletal muscle. It operates under voluntary control and so is additionally known as voluntary muscle.

The second muscle type is smooth muscle, which has few actin and myosin filaments; therefore, it has few striations. Smooth muscle is found in the linings of the blood vessels, along the gastrointestinal tract, in the respiratory tract, and in the urinary bladder. Because it operates without voluntary control, it is sometimes called involuntary muscle.

The third muscle type is cardiac muscle, which is found in the heart. It has striations because it has multiple actin and myosin filaments, but it is involuntary muscle. The actin and myosin filaments in cardiac muscle exist as intertwined branches that form a conducting network for nerve impulses.

Skeletal muscle is further divided into several subtypes:

  • slow oxidative, slow twitch, or "red" muscle is dense with capillaries and is rich in mitochondria and myoglobin, giving the muscle tissue its characteristic red color. It can carry more oxygen and sustain aerobic activity.
  • fast twitch muscle, has three major kinds that are, in order of increasing contractile speed:
    • type IIq, which,like slow muscle, is aerobic, rich in mitochondria and capillaries and appears red.
    • Type IIx (also known as type IId), which is less dense in mitochondria and myoglobin. This is the fastest muscle type in humans. It can contract more quickly and with a greater amount of force than oxidative muscle, but can sustain only short, anaerobic bursts of activity before muscle contraction becomes painful (often incorrectly attributed to a build-up of lactic acid). N.B. in some books and articles this muscle in humans was, confusingly, called type IIB.
    • Type IIb, which is anaerobic, glycolytic, "white" muscle that is even less dense in mitochondria and myoglobin. In small animals like rodents this is the major fast muscle type, explaining the pale color of their flesh.

The History of Cell Theory

An interesting article on the Historical Perspective of Cell Theory.

Reading material:

Mr. Low

Monday, January 11, 2010

3 questions that you will find interesting with regards to Health Science

Question 4

4. What are the categories of cells you can find from the reading?
Please put your answers in the comments.

Question 3

3. How are the components in the cells identified after the development of Cell Theory and what are the components identified?
Please put your answers in the comments.

Question 2

2. Who are the 3 scientists that led to the development of Cell Theory?
Please put your answers in the comments.

Question 1

1. How does the Cell Theory explain the relationship between living things and cells?
Please put your answers in the comments.

Key Understanding of Cells

Please put your answers in the comments. Thank you.