How to Build a Telescope

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In its essence, a telescope is an instrument that makes a far away object look closer. To do this, a telescope has a device that collects light from a distant object (objective lens or primary mirror) and brings that light (image) to a focus where a second device (eyepiece lens) magnifies the image and brings it to your eye. To make a simple telescope at home, you will need the following:

  • Two magnifying glasses – perhaps 1 – 1.5 inches (2.5-3 cm) diameter (it works best if one is larger than the other)
  • A cardboard tube – paper towel roll or gift-wrapping paper roll (it helps if it is long)
  • Duct tape
  • Scissors
  • A ruler, yard stick, or tape measure
  • Sheet of printed paper – newspaper or magazine will do

INSTRUCTIONS:

  1. Get the two magnifying glasses and a sheet of printed-paper.
  2. Hold one magnifying glass (the bigger one) between you and the paper. The image of the print will look blurry.
  3. Place the second magnifying glass between your eye and the first magnifying glass.
  4. Move the second glass forward or backward until the print comes into sharp focus. You will notice that the print appears larger and upside down.
  5. Have a friend measure the distance between the two magnifying glasses and write the distance down.
  6. Cut a slot in the cardboard tube near the front opening about an inch (2.5 cm) away. Do not cut all the way through the tube. The slot should be able to hold the large magnifying glass.
  7. Cut a second slot

In the tube the same distance from the first slot as your friend wrote down. This is where the second magnifying glass will go.

  1. Place the two magnifying glasses in their slots (big one at front, little one at back) and tape them in with the duct tape
  2. Leave about 0.5 – 1 inch (1 – 2 cm) of tube behind the small magnifying glass and cut off any excess tube remaining

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Binary fission – The Amoeba

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Amoebae are single-celled, crawling organisms often found in ponds. They have no definite shape and consist of flowing cytoplasm encased in a very flexible cell membrane. Amoebae have organelles (including one or more nuclei) and a contractile vacuole.

 

  1. Movement
  2. Amoebae move when cytoplasm flows out into a long extension of the cell; this crawling, flowing motion is called psuedopodia.
  3. Habitat
  4. Most amoebae live in pond water, moist soil or the ocean; some species are parasitic, living inside the body of another organism.
  5. Diet
  6. Amoebae ingest food through phagocytosis (the process whereby a cell engulfs a piece of food and ingests it). Basically tiny predators, they feed mainly on other microorganisms.
  7. Osmoregulation
  8. Amoebae that live in freshwater ponds must deal with water constantly rushing into the cell. Organelles called contractile vacuoles constantly fill with excess water, and pump it out of the cell. Without a contractile vacuole, the amoeba would explode in a freshwater environment.
  9. Size
  10. Although they are fairly large cells, most amoebas are too small to see with the naked eye; however, some species grow to grape size.

REPRODUCTION:
Binary Fission in amoeba:
Most single celled organisms use the method of binary fission for cell division and reproduction. These include paramoecium, bacterium, and finally amoeba. In this paragraph we will be focusing on amoeba’s cell division which is also its method of reproduction. In binary fission the amoeba consists of one parent which forms the 2 daughter cells. First, the amoeba cell undergoes nuclear division and replicates into two nuclei. The two nuclei divide and move to opposite directions in the parent cell. The cell then produces protiens and nutrients in preperation for binary fission. In the stage of binary fission, the cell divides and forms 2 daughter cells. This process generally occurs when environmental conditions are most favourable. That is, when there is enough food, water, and a favourable temperature.

Bibliography:

http://en.wikipedia.org/wiki/Fission_(biology)

http://www.scienceclarified.com/Al-As/Amoeba.html

http://www.enchantedlearning.com/paint/subjects/protists/amoeba.shtml