paper 2

• what name is given to all of the organisms in the same habitat?

  a community
• scientists think two birds belong to diffrent species. What evidence is used to support this?

  they cannot bread together to give fertile offsping
• what term describes the adjustment of focus from the distant object to the near object?

  accommodation
• what happens to the shape of the lense when focusing on a near object?

  it becomes thicker
• The eyes can function in dimly-lit areas,

  The iris contains mucles,

  Describe how mucles in the iris help the person to see clearly when moving from a dimly light area to a brighly lit area.

  Muscles in the iris contract, reducing the pupil size and allowing less light to enter.
• suggest one example of growing tomato plants that are genetically identical.

  they grow at the same rate / can be harvested at the same time.
• scientists can grow genetically identical tomato plants using tissue culture, what is tissue culture?

  a group of cells grown into a new organism
• a famer wants to produce a new variety of chicken that is good for both meat production (variety A) and egg production (variety B).

  describe how selective breeding of chicken varietys A and B can produce a new variety of chicken.

  breed the best of variety A and B together, select offsping with the highest egg numbers and the heavest, breed there offsping together and repeat over several generations.
• Milk contains lipids. lipids are broken down when milk decays. Explain why the pH changes quicker when the temprature is higher.

  enzymes are more active, lipids are broken down quicker so fatty acids are produces quicker (that decreases/changes pH)