Pollination

• Pollination: transfer of pollen grains from the male part of the plant (anther of stamen) to the female part of the plant (stigma).
• Agents of pollination: insects, birds, mammals, water and wind
• Insect pollinated plants: sweetly scented

  Wind pollinated plants: no scent
• Insect pollinated plants: large colourful petals

  Wind pollinated plants: dull petals
• Insect pollinated plants: nectaries

  Wind pollinated plants: no nectaries
• Insect pollinated plants: moderate amount of pollen

  Wind pollinated plants: huge amount of pollen
• Insect pollinated plants: pollen is spiky/sticky

  Wind pollinated plants: pollen is round and smooth
• Insect pollinated plants: anther & stigma inside flower

  Wind pollinated plants: anther & stigma hangs out
• Insect pollinated plants: stick stigma

  Wind pollinated plants: stigma hairy
• Insect pollinated plants have flowers with stripes which act as guide-lines for insects
• Pollen tube: pollen grain lands on stigma and creates a tunnel down the style, through the micropyle, to the ovules.
• What kind of seed is this the structure of?

  Non-endospermic

  
• Formation of a seed: the zygote divides many times by mitosis to form and embryo. The cotyledon is the food store. The testa stops drying out of embryo.
• Wind and animal dispersal are used by plants to colonise new areas; done because new areas have less competition for light, space and nutrients, so seeds are more likely to develop.
• The dandelion is an example of a wind dispersed seed

  
• The sycamore is an example of a wind dispersed seed

  
• The apple is an example of an animal dispersed seed

  
• The bur is an example of an animal dispersed seed