Transcript Plant Anatomy

Plant Anatomy
Flower: Is for reproduction.
- It has the plant’s sexual organs
Stem: Supports the plant and carries water
and nutrients
Leaves: Receive sunlight and CO2
- Releases water and O2
Roots: Hold the plant in the ground
- Absorbs water and nutrients
1. Stamen: Male parts of a flower
- Anther (with pollen) and the filament
2. Carpels/ Pistal: Female parts of flower
- Stigma, style and ovary (female sex cells)
3. Petals: Generally brightly coloured and
attach insects.
4. Sepals: Are green/ leaf like and protect the
flower. They are found below the petals.
Pollination
1.
2.
Self Pollination: pollen transfers from
stamen to stigma on same plant
Cross Pollination: Pollen transfers from
stamen on one plant to stigma of another.
Insect Pollination: Bright coloured petals,
scented flowers, sticky stigma, only makes a
small amount of pollen
Wind Pollination: usually small, dull petals,
no scent, long filaments (so pollen can blow
away), stigmas are “feathery”
Characteristics of insect-pollinated flowers:
1.Flowers are usually large, brightly-colored and
scented to attract insects. If the flowers are small they
may group together.
2.Nectar is often present to attract insects.
3.Pollen is abundant. Pollen grains are large, sticky and
heavy, usually with rough surfaces so that they can
readily cling onto the insects bodies.
4.Stamens may be stiff.
5.Stigmas are usually not feathery and do no protrude.
They are sticky so that pollen grains settling on them are
not easily displaced.
6.Nectar guides may be seen on the petals (lines on
flowers).
Characteristics of wind-pollinated flowers:
1.Flowers are usually small, dull-colored and scentless
and thus not attractive to insects.
2.Usually no nector.
3.Pollen is abundant as wastage is higher. Pollen grains are
small, dry, smooth and light so that they are buoyant and
easily blown about by air currents.
4.Stamens usually have long, slender filaments that sway in
the slightest wind and pollen grains are hence shaken out
from the anthers.
5.Stigmas protrude and are large and feathery so that
they provide a large surface area to catch pollen floating in
the air.
Fertilization
Definition: The joining of sex cells
Pollen grains germinate on the stigma, growing
down the style to reach an ovule.
Fertilised ovules develop into seeds.
The carpel enlarges to form the flesh of the
fruit and to protect the ovary
After fertilization the petals and stamens
wither and die.
Seed Dispersal
Seeds are dispersed in many different ways:
 Wind
 Explosion
 Water
 Animals
 Birds
 Scatter
Germination

Seeds need specific:
-
Temperature
Air conditions (oxygen)
Enough water
-
Seeds will lie dormant until everything is
perfect for them
Plant Growth
For photosynthesis
1. Sunlight
2. Water
3. Temperature
4. CO2
Essential Minerals
1. Nitrates (yellow older leaves if missing)
2. Phosphates (Purple leaves if missing)
3. Potassium (yellow leaves and dead bits)