Science at key stage 3 (Year 7)
Unit 7A: Cells
Section 9: b. How are new cells made?
|
|
Objectives |
| Children should learn: |
- that cells have nuclei containing the information that is transferred from one generation to the next
- that in plants, pollen and ovule are specialised cells which enable information to be transferred from one generation to the next
- that at fertilisation, nuclei from pollen and ovule fuse to make a new and unique individual
|
Activities |
|
Outcomes |
|
Children: |
- Ask pupils what they remember about pollination and sexual reproduction in plants. Extend their ideas about pollen and ovule by establishing that these are the male and female reproductive cells of plants, and help them to observe pollen and ovules under the microscope at low magnification. Describe the process of fertilisation in plants as the transmission of information within a nucleus of the pollen grain to the ovule, and the combination of the nuclei of ovule and pollen grain to form a new cell. Prepare slides of pollen grains,
eg from lilies, in 10% sugar solution and help pupils to observe the growth of pollen tubes. Establish that the new cell grows to form a seed, making new cells by division.
|
|
- explain the process of fertilisation in flowering plants as the transfer of information within nuclei from parents to offspring
- distinguish between the processes of pollination and fertilisation in flowering plants
- make drawings to illustrate the sequence of events during fertilisation in plants
|
|
Points to note |
- Pupils should be familiar with sexual reproduction in plants and with flower structure from work at key stage 2.
- Details of fertilisation in flowering plants are not required at this stage. Fertilisation in plants and animals will be revisited in unit 9A 'Inheritance and selection' and fertilisation in humans is described in unit 7B 'Reproduction'.
- Pollen and ovules are easily observed in any simple flower with large stamens and ovaries,
eg wallflower, daffodil, godetia, nasturtium, tulip. A range of flowers from the same species will provide pollen at different stages of maturity.
|
|
|
This unit is divided into sections. Each section contains a sequence of
activities with related objectives and outcomes. You can view this unit by
moving through the sections or print/download the whole unit.
|
|
|
