2.8. Sowing seeds

• Biologie
• Middelbare school
• vmbo t, mavo, havo
• Leerjaar 1

LESSON 16

• Quiz?
• Repeat 2.6. + 2.7.
• 2.8. Sowing the seeds
• Do your homework

What is pollination?

Represents situation 3 no pollination, self-pollination or cross-pollination?

1. no pollination
2. self-pollination
3. cross-pollination

What is fertilisation?

Which is part of a seed?

1. flower
2. embryo
3. pollen
4. fruit

Which is part of a fruit?

1. flower
2. seed
3. pollen
4. leaf

Label part 9

Label part 3

Label part 7

2.8. SOWING THE SEEDS

• After a plant has been pollinated and then fertilised, it send its seeds into the world. 

2.8. SOWING THE SEEDS

• After a plant has been pollinated and then fertilised, it send its seeds into the world. 
• Plants have developed ways to make sure that their seeds are transported a good distance away from them. 

2.8. SOWING THE SEEDS

• After a plant has been pollinated and then fertilised, it send its seeds into the world. 
• Plants have developed ways to make sure that their seeds are transported a good distance away from them. 
• This is called seed dispersal (zaadverspreiding). 

Seeds can be dispersed in different ways. Can you think of a way?

2.8. SOWING THE SEEDS

There are 4 different ways:

1. Dispersal by animals
2. Dispersal by wind
3. Dispersal by water
4. Dispersal by explosion 

1. Dispersal by animals

• Birds and other animals eat the fruits of a plant, the seeds are not digested but excreted in their droppings elsewhere. 

1. Dispersal by animals

• Birds and other animals eat the fruits of a plant, the seeds are not digested but excreted in their droppings elsewhere. 
• Edible seeds without fleshy fruit (acorns/hazulnuts) are collected by animals and buried in the soil. 

1. Dispersal by animals

• Birds and other animals eat the fruits of a plant, the seeds are not digested but excreted in their droppings elsewhere. 
• Edible seeds without fleshy fruit (acorns/hazulnuts) are collected by animals and buried in the soil. 
• There are also seeds which act like hitchhikers. These seeds have hooks on them and cling to the fur of animals that brush against them. 

2. Dispersal by wind

Pepper-pot type

The ovaries grow into hollow containers with one or more openings. The containers are shaken by the wind, scattering the seeds through the openings, dispersing them all aournd the immediate area. 

2. Dispersal by wind

Parachute type

The seeds have feathery hairs that look work like parachutes. This helps the seeds catch the wind and float away. 

2. Dispersal by wind

Winged type

Wing-like outgrowths on the fruit make it spin as it falls away from the parent plant. This spinning slows its fall so that the wind can carry it some distance away. 

3. Dispersal by water

• Some seeds fall into water and get dispersed a second time.

3. Dispersal by water

• Some seeds fall into water and get dispersed a second time.
• Some plants grow near or in water and let their seeds fall into the water.  

4. Explosive dispersal

• Some plants disperse their seeds by ejecting them with great force. 

4. Explosive dispersal

• Some plants disperse their seeds by ejecting them with great force. 
• As a pod dries, tensions grow in its walls. As the two halves of the pod suddenly split open, they throw the seeds out in an explosive manner. 

HOMEWORK

Friday 4 February

Complete the Google Form '2.8. Sowing the seeds' on Google Classroom