-When the pollen grain lands on the Stigma, it travels down the pollen tube and enters the ovule.
-When the pollen grain fertilises with the ovule;
- Zygote will form and later the Zygotes will later divide and turn into an embryo.
- Seed coat called the Testa will form outside of the ovule.
- Cotyledons form inside the ovary, the Cotyledons store food for the seedlings.
- The wall of the ovary thickens because it starts to store foods such as protein, sugars etc. and starts to form a fruit.
Sunday, April 24, 2011
Sunday, April 3, 2011
(I)GCSE Topic 3.3 b) Wind Pollination
-Transfer of the pollen grain from the Anther to the Stigma through air, carried by the wind.
-Light weight pollen grains with a feature which allows them to move through the air more efficiently.
-Anthers will hang well clear over the basic flower structure so that they are exposed to the wind.
-Stigma have really large surface areas with a feature-like structure to catch the pollen grains as they pass through the air on the wind.
-No coulor, no scent, no nectaries needed to attract insects because they are wind pollinated.
-Light weight pollen grains with a feature which allows them to move through the air more efficiently.
-Anthers will hang well clear over the basic flower structure so that they are exposed to the wind.
-Stigma have really large surface areas with a feature-like structure to catch the pollen grains as they pass through the air on the wind.
-No coulor, no scent, no nectaries needed to attract insects because they are wind pollinated.
(I)GCSE Topic 3.3 a) Insect-Pollination
-In the process of pollination, there has to be a transfer of pollen grains from the anthers of a flower to the stigma of another.
-Pollen is a small structure of the plant which contains the male neuclei.
-The transfer of Insect Pollination takes place by Insects. And so it is neccessary for the insect to be attracted by the first flower and have a reason to go into the second flower.
-The pollen of one plant going into another is called 'Cross Polination'.
-Things attracting the Insects: coloured petals, Scents, Value to the insect for going to the plant is food which is fructose/nectaties.
-Stamen is the male part of the plant which produces the pollen granes. The anther and the fillament form the stamen.
-The female part of the plant contains Stigme, Style, Ovary. This whole structure is called the CARPOL.
-Pollen is a small structure of the plant which contains the male neuclei.
-The transfer of Insect Pollination takes place by Insects. And so it is neccessary for the insect to be attracted by the first flower and have a reason to go into the second flower.
-The pollen of one plant going into another is called 'Cross Polination'.
-Things attracting the Insects: coloured petals, Scents, Value to the insect for going to the plant is food which is fructose/nectaties.
-Stamen is the male part of the plant which produces the pollen granes. The anther and the fillament form the stamen.
-The female part of the plant contains Stigme, Style, Ovary. This whole structure is called the CARPOL.
Sunday, March 27, 2011
(I)GCSE Topic 2.80 Geotropism
'GEO'tropism refers o gravity and 'TROPISM' refers to growth response to gravity.
(I)GCSE Topic 2.79 Plants Respond to Stimuli
-Stimuli = changes in the environment e.g. temperature changes, light changes.
-Plants have receptors which can detect these stimulis. The response to this is often growth of the plants.
-Growth in response to Stimulis is called Tropism. Tropism involving light is called Phototropism. Tropism involving gravity is called Geotropism.
-Connection between Receptor and Response usually take the form of plants hormones.
-Plants have receptors which can detect these stimulis. The response to this is often growth of the plants.
-Growth in response to Stimulis is called Tropism. Tropism involving light is called Phototropism. Tropism involving gravity is called Geotropism.
-Connection between Receptor and Response usually take the form of plants hormones.
Subscribe to:
Posts (Atom)