Biology - Unit 1

Question 1

CELL THEORY

Answer 1

• All living things are composed of cells and cell products
• New cells are formed by the division of pre-existing cells
• Cells contain inherited information, which is used for instructions for growth, development, and functioning.

Question 2

PROKARYOTIC CELLS

Answer 2

• Plant and Animal Cells
• Has a nucleus
• Has a membrane- bound organelle
• Multi-cellular organism

Question 3

EUKARYOTIC CELL

Answer 3

• Bacteria Cell
• Has no nucleus
• Has no membrane-bound organelle
• Single-cellular organism

Question 4

LIGHT MICROSCOPE

Answer 4

• Uses visible light to observe small objects
• Uses reflection
• Positive - Allows to observe sub-cellular objects
• Limitations - Lower magnification (x500) and resolution (x200)

Question 5

ELECTRON MICROSCOPE

Answer 5

• Uses beam of electrons in a vacuum with a wavelength less than 1nm to visualize the specimen
• Uses diffraction
• Positive - Has high magnification (x50000) and resolution (-0.1nm)
• Limitations - Destroys the sample
• Higher resolution due to the smaller wavleengths of electrons.

Question 6

MAGNIFICATION FORMULA

Answer 6

Size of image DIVIDE Actual Size x 100