Seeds and Seeds
You must have seen many types of seeds. Some seeds are small and some are large. Seeds of mustard are small, while seed of coconut is quite large. Seeds come in different shapes. Some are round, some are flat and some appear like capsules. Some seeds are smooth while some are rough. Seeds come in many colours.
Germination of Seed
A seed contains a baby plant and some food for the baby plant. When a seed starts to change in a plant, the process is called germination of seed. A seed need proper temperature, water and air to germinate. Following are the steps of seed germination.
- A sprout comes out of the seed. The sprout looks like small hair which is white in colour.
- New leaves come out of sprout. This is the baby plant.
- The baby plant then grows further.
Seeds travel far and wide. This helps them to produce plants in new areas. Different seeds travel by different methods.
Fig: From left to right: Seeds of dandelion, maple, beggar tick and coconut
- Seeds of dandelion travel by floating on air. A seed of dandelion has fine cotton like hairs on top. These hairs help it in floating on air.
- Seeds of maple have wings on them. They fly in air with wings.
- Seeds of beggar tick have hooks all over. These hooks help the seed in sticking to fur of an animal. That is how a seed of beggar tick travels to different places.
- Some seeds are spread by birds and other animals. When a bird eats a fruit, it drops the seeds at different places.
- A seed of coconut floats on water. That is how, coconut seeds travel to different places.
- Some seeds are spread by humans. Once upon a time, potatoes were grown only in South America. Potatoes traveled to different countries along with traders. Now, potato is grown all over the world.
Chillies also came from South America. Cabbage came from Europe. Bhindi or okra came from Africa.
- Take some chana (gram) and three bowls.
- Put five grains of chana in each bowl.
- Fill the first bowl with water. Put a damp piece of cloth in second bowl. Keep only chana seeds in the third bowl.
- Observe after a week and note the changes in the bowls
|Bowl 1||Bowl 2||Bowl 3|
|Are the seeds getting air?||No||Yes||Yes|
|Are the seeds getting water?||Yes||yes||No|
|What changes did you see?||Size of seeds increased.||Size of seeds increased.||No change|
|Have the seeds sprouted?||No||Yes||No|
Conclusion: Both water and air are necessary for germination of seeds. A seed cannot germinate if any of the two is not available.
Question 1: What things are soaked before cooking in your house? Why?
Answer: Dal (Lentil), chana (chick pea), rice
Question 2: What things do you eat after sprouting? How are they sprouted? How much time does it take?
Answer: I eat chana and moong after sprouting. They are soaked in water overnight. After that, the seeds are kept in moist cloth. It takes about five to seven days for seeds to sprout.
Question 3: Has the doctor or someone you know ever told you to eat sprouts? Why?
Answer: Once a doctor told me to eat sprouts. He told that sprouts have many vitamins and they make us healthy.
Question 4: What is inside the seed?
Answer: A seed has a baby plant inside.
Question 5: How does a big plant grow from a tiny seed?
Answer: First of all, a seed germinates to give a baby plant. After that, the baby plant grows into a big plant.
Question 6: Do some plants grow without seeds?
Answer: Yes, there are many plants which grow without seeds. Some examples are, banana, rose, sugar cane, etc.
Question 7: Make lists of
(a) Seeds that are used as spices in your home.
Answer: Carom seeds, mustard, cumin, fenugreek, coriander, etc.
(b) Seeds of vegetables.
Answer: Pea, tomato, brinjal
(c) Seeds of fruits.
Answer: Mango, jackfruit, coconut, guava
(d) Light seeds (check by blowing them).
Answer: Azwain, carom seeds
(e) Seeds which are flat.
Answer: Sesame, maize, melon