Fertilisation and germination Flashcards
What do we call it when the nucleus of a pollen grain and ovule fuse together?
Fertilisation.
Describe how fertilisation, in flowering plants, leads to the formation of a fruit containing seeds.
Pollen grain lands on stigma. Tube grows from pollen grain down through style. The pollen nucleus moves down the tube. The pollen nucleus joins with the ovule nucleus (fertilisation). A fruit containing seeds will then form.
Which part of a flowering plant turns into a fruit after fertilisation has happened?
The ovary.
Which part of a flowering plant turns into the seeds after fertilisation has happened?
Ovules.
Which 3 parts do all seeds have?
A seed coat. An embryo. A food store (starch).
What is the function of the seed coat of a seed?
It protects the seed.
What is the function of the food store of a seed?
It provides food to the plant embryo before it starts to do photosynthesis.
What do we call it when a seed first starts to grow?
Germination.
What does a seed need to germinate?
Water, Warmth, Oxygen.
Why does a seed need water to germinate?
It makes the seed swell up, breaks the seed coat and allows the embryo to start growing.
Why does a seed need warmth to germinate?
Warmth speeds up the chemical reactions happening in the seed.
Why does a seed need oxygen to germinate?
To allow the seed to do respiration (produce energy).
Describe the steps involved when a seed starts to germinate and grow.
The seed rapidly absorbs water which causes seed coat to split. The roots grow down and the shoot grows up. The first leaves start to appear so the plant makes its own food via photosynthesis. More leaves start to appear and the plant uses photosynthesis to meet all of its energy demands.
