Monday, 25 February 2008
Sunday, 17 February 2008
Binary Fission - Another kind of cell reproduction
The video below gives a detailed description of the cell division process. You need not remember the details and the names of the various processes. You only need to know the general idea of how a cell divides.
Saturday, 16 February 2008
DNA Workshop @ Science Centre
Having experienced being a scientist extracting DNA from the E Coli bacteria, I'm sure all of you have lots to say. Think about what you have learnt, discovered and enjoyed. Write your feelings and experiences down in this blog!
3o% similar to yeast,
40% simiar to a worm,
50% similar to a banana,
60% similar to a fruitfly,
90% similar to a mouse
and
99.9% similar to an ape!
Information & picture taken at the workshop.
This the bacteria DNA which Hui Ning has extracted. Can you see it?
Here are the photographs taken at the workshop. Enjoy!
How alike are we to these living things?
Our DNA is
3o% similar to yeast,
40% simiar to a worm,
50% similar to a banana,
60% similar to a fruitfly,
90% similar to a mouse
and
99.9% similar to an ape!
Information & picture taken at the workshop.
This the bacteria DNA which Hui Ning has extracted. Can you see it?
Here are the photographs taken at the workshop. Enjoy!
Saturday, 9 February 2008
Maths - The Order of Operations
Here's a game which you can play & at the same time get better with the BoDMAS Rule.
Funbrain.com's Operation Order Algebra Game
Order of Operations - Mystery Picture Game 1
Order of Operations - Mystery Picture Game 2
Order of Operations - Mystery Picture Game 3
An online worksheet for you to try: Online Order of Operations
Funbrain.com's Operation Order Algebra Game
Order of Operations - Mystery Picture Game 1
Order of Operations - Mystery Picture Game 2
Order of Operations - Mystery Picture Game 3
An online worksheet for you to try: Online Order of Operations
Saturday, 2 February 2008
Other microscopic organisms
Below are videos of some microscopic organisms. Some of their pictures can be found in the Activity Book.
Daphnia - microscopic crustaceans belonging to the order Cladocera. Also known as water fleas, they populate the quiet waters of lakes and ponds throughout the world. Most species are found in freshwater habitats, but a few occur in marine environments.
Daphnia - microscopic crustaceans belonging to the order Cladocera. Also known as water fleas, they populate the quiet waters of lakes and ponds throughout the world. Most species are found in freshwater habitats, but a few occur in marine environments.
The Unit of Life - Yeast Budding
Watch the video to see how yeast, a single-cell organism, reproduce. This method of reproduction is budding.
Friday, 1 February 2008
Single-celled organisms - Protozoans
These one-celled organisms belong to the Kingdom Protista, which includes algae and lower fungi. Although most species of protozoans are invisible to the naked eye, they dominate the Earth's environment, occurring everywhere and in an amazing diversity of forms and functions.
Watch these videos to see how these organisms behave which we normally cannot see just with our eyes!
Paramecium - a slipper-shaped ciliate which is commonly found in freshwater ponds around the world.
Amoeba - a primitive organism characterized by its flowing movements, extending cytoplasm outward to form pseudopodia (false feet); this type of movement is considered to be the most primitive form of animal locomotion. Pseudopodia are also used for feeding. In response to chemical stimuli from smaller organisms, pseudopodia are induced to envelop the organism, at the same time forming a vacuole (cavity). Digestive enzymes are secreted into the cavity and the nutrients diffuse from the vacuole into the cytoplasm. Undigested food and wastes are eliminated through the ectoplasm. The ectoplasm also performs respiration, absorbing oxygen from the water and eliminating carbon dioxide. Amoebas reproduce asexually by binary fission.
Another video clip of amoeba
Euglena - a member of the protozoan order Euglenida, a remarkable group of single-celled creatures, many of which exhibit characteristics of both plants and animals. Like many protozoans, it is free-living, using a whiplike flagellum to move about. Euglena is one of the euglenoid genera that contain chlorophyll, allowing them to create their own food through photosynthesis. Euglena live in a variety of aquatic habitats, both freshwater and marine.
Some species that don't have a rigid cellulose wall have a flexible pellicle (envelope) that allows them to change their shapes. Food is absorbed directly through the cell surface or produced by photosynthesis; then it is stored as a complex carbohydrate. Euglena reproduce asexually, by longitudinal cell division; they are not know to reproduce sexually. Several species produce resting cysts that can withstand drying. Euglena live in fresh and brackish water habitats rich in organic matter. Some species develop tremendous populations as green or red "blooms" in ponds or lakes. Several colorless species are used to study cell growth and metabolism at high temperatures.
Closterium - a desmid, a microscopic green algae that occurs in all types of freshwater habitats. Desmids are typically one-celled, though sometimes filamentous or colonial, and are divided symmetrically into semicells connected at a central point. Closterium is characterized by a sickle shape and sometimes contains gypsum crystals.
Frustulia - one of 16,000 species of diatoms, one of the many groups of organisms that make up the algae. Diatoms are photosynthetic, but have rigid cell walls reinforced with silicon rather than cellulose. They can be found in all aquatic environments and, although they're unicellular, often live in large colonies.
Watch these videos to see how these organisms behave which we normally cannot see just with our eyes!
Paramecium - a slipper-shaped ciliate which is commonly found in freshwater ponds around the world.
Amoeba - a primitive organism characterized by its flowing movements, extending cytoplasm outward to form pseudopodia (false feet); this type of movement is considered to be the most primitive form of animal locomotion. Pseudopodia are also used for feeding. In response to chemical stimuli from smaller organisms, pseudopodia are induced to envelop the organism, at the same time forming a vacuole (cavity). Digestive enzymes are secreted into the cavity and the nutrients diffuse from the vacuole into the cytoplasm. Undigested food and wastes are eliminated through the ectoplasm. The ectoplasm also performs respiration, absorbing oxygen from the water and eliminating carbon dioxide. Amoebas reproduce asexually by binary fission.
Another video clip of amoeba
Euglena - a member of the protozoan order Euglenida, a remarkable group of single-celled creatures, many of which exhibit characteristics of both plants and animals. Like many protozoans, it is free-living, using a whiplike flagellum to move about. Euglena is one of the euglenoid genera that contain chlorophyll, allowing them to create their own food through photosynthesis. Euglena live in a variety of aquatic habitats, both freshwater and marine.
Some species that don't have a rigid cellulose wall have a flexible pellicle (envelope) that allows them to change their shapes. Food is absorbed directly through the cell surface or produced by photosynthesis; then it is stored as a complex carbohydrate. Euglena reproduce asexually, by longitudinal cell division; they are not know to reproduce sexually. Several species produce resting cysts that can withstand drying. Euglena live in fresh and brackish water habitats rich in organic matter. Some species develop tremendous populations as green or red "blooms" in ponds or lakes. Several colorless species are used to study cell growth and metabolism at high temperatures.
Closterium - a desmid, a microscopic green algae that occurs in all types of freshwater habitats. Desmids are typically one-celled, though sometimes filamentous or colonial, and are divided symmetrically into semicells connected at a central point. Closterium is characterized by a sickle shape and sometimes contains gypsum crystals.
Frustulia - one of 16,000 species of diatoms, one of the many groups of organisms that make up the algae. Diatoms are photosynthetic, but have rigid cell walls reinforced with silicon rather than cellulose. They can be found in all aquatic environments and, although they're unicellular, often live in large colonies.
Discussion: Things made from materials that were once alive have cells too.
Do you agree with the statement above? Give evidence to support your argument. You may do some research before putting your comments.
Remember to identify yourself.
Remember to identify yourself.
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