Fertilisation questions

• What controls the growth of the pollen tube down into the ovule?

  The tube nucleus
• What's the opening of the ovule called in which the nuclei enter?

  The microphyll
• What are the two products of double fertilisation?

  A zygote and an endosperm
• What happens to the integuments in the ovule?

  They will dry up and form the testa of the seed. This is the coat of the seed.
• How is the fruit formed?

  The ovary will swell and produce the fruit after double fertilisation. The role of the fruit is to protect the seed.
• What is the seed?

  It's the embryo plant and the food reserve surrounded by a protective coat.
• What are the parts that make up the seed?

  The radicle-becomes the root, plumule-becomes the shoot and the cotyledons-the seed leaves
• How many cotyledons do monocots have?

  One
• How many cotyledons dicots have?

  Two
• Whats's an endospermic seed and give an example?

  A seed that still has it's endosperm and stores it's food here, an example is maize
• What's a non-endospermic seed and give an example?

  A seed that has absorbed it's endosperm and now stores it's food in it's cotyledons. An example of this is a broad bean.
• Why is dormancy important for plants?

  It allows the plant to wait for favourable conditions to grow which increases it's chances of survival. It also gives the seed time to be dispersed.
• What is the importance of seed and fruit dispersal?

  It ensures the seed is far away from the parent plant to avoid competition with the parent plant.
• Germination and factors required

  The rapid regrowth of the embryo plant following a period of dormancy. Factors required are water, oxygen and a suitable temperature
• What's the part of the embryo plant thats above the cotyledons and above the plumule?

  The epicotyl
• What's the part of the below the cotyledons and above the radicle?

  Hypocotyl
• Hypogeal Germination

  Cotyledons stay below ground. Radicle grows down into the soil and the epicotyl grows pulling the hooked plumule above the ground.
• Epigeal Germination

  Cotyledons are raised above the ground. Radicle grows down into the soil and hypogeal forms a hook pulling the cotyledons above ground
• What is dormancy in seeds?

  A period of reduced metabolic activity where the seed undergoes no growth