GRADE SIX SCIENCE

Hello Boys and Girls, Have you been revising? When will you be having your End of Term tests? Work hard at getting your best results and do have a great week!

For the last few weeks we have been looking at parts of the plant. We are still examining the flower. Let’s go back a bit and find out how much you know about the parts of the flower. What is pollination? Name two types of pollination. State three agents of pollination.

Look at the table below which serves to remind you of the differences between wind and insect pollinated flowers. Compare the table with those seen last week. Did you get any added knowledge? We also looked at fertilisation. We found that fertilisation follows pollination. After pollination has occurred, the male cell then has to reach the female cell for fertilisation to take place. How really does this happen? First a pollen grain falls on the stigma of the flower and swells then develops a pollen tube. The pollen tube then grows all the way down the style then through the wall of the ovary. When in the ovary the male and female cells meet and a zygote is formed. This process is known as fertilisation. After fertilisation, each ovule develops into a seed. The ovary wall develops into the fruit. We know that the fruit contains seeds. A fruit contains one or more seeds; the number depends on the number of ovules in the ovary that were fertilised. Very often the shape and structure of many fruits are very similar to the original ovary. After fertilisation the fruit may develop. The parts of the flower that are no longer needed, wither (dry out) and drop off. (Can you think of anything in nature that gets rid of what it no longer uses?) The ovule (or ovules) develop(s) into the seed(s) and the ovary becomes the fruit. Sometimes the receptacle or cup may form part of the fruit. Thus pollination and fertilisation lead to fruit formation. Let us look at fruits and seeds for a short while. Fruits are very good for you. Discuss with your friend the ways in which fruits are good for you. If you observe, you will find that there are many types of fruits. Some are soft and fleshy. Most of the fruits that we like to eat, such a papaw, mango and pear, are soft and fleshy. Can you name any other soft, fleshy fruits? Many fruits are hard and dry. One such fruit that we eat is the ground nut or peanut. Think of a few more examples. Compare them with a friend or two. Collect pictures of fruits of all kinds, paste them in your scrap book and label them. Fruits may also be of different shapes and sizes. When ripe they are usually different in colour. They tend to change in colour (and sometimes texture) when ripe or mature. The skins of fruit often change in colour when ripe. A fruit has an outer covering or skin which may be thin, thick, smooth, rough, hairy or thorny. Observe a few different types of fruits then complete the table which follows.

Put a tick in the appropriate column. Until next week, be good Boys and Girls and eat lots of fruits. Do keep revising.