microscope

1. MICROSCOPE
• Two properties:
1. Magnification: the ability of the microscope
to increase the size of the image of an object
formed on the retina of the eye.
2. It can be represented as:
MP =Size of retinal image formed with the microscope ( size of image)
Size of retinal image formed with unaided normal eye (size of specimen)
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2. TGES BIOLOGY IBDP
Resolving power
• The ability of a microscope or any magnifying instrument to
separate or distinguish between two closely placed points.
• This depends on the wave length and the light gathering
capacity of the objective lens- numerical aperture.

3. Light microscope:
The source of
illumination is light.
Electron microscope:
The source of illumination
is electron beam.

4. Compound microscope
Compound microscope is a combination
of two simple microscopes.
Compound microscope has two
lenses.

5. Electron microscope

6. Insect pollination
Petal – colourful, scented. Attracts insects to
the flower

7. Insect pollination
Anther – contains pollen sacs, in which are the
pollen grains (male gametes)

8. Insect pollination
Filament – holds the anther so that insects
will brush against it and collect pollen

9. Insect pollination
Together, the anther and the filament make
up the stamen, the male part of the flower

10. Insect pollination
Stigma – sticky, collects the pollen from
insects visiting the flower.

11. Insect pollination
Style – the pollen tube grows through this on
its way to the ovary

12. Insect pollination
Ovary – contains the ovules, the female parts
of the flower

13. Insect pollination
Ovule – this will develop into the seed when
the egg cell (female gamete) is fertilised

14. Insect pollination
Together, the stigma, style and ovary make up
the carpel, the female reproductive structure
in the flower