Pollination. - experiment to study seed dispersal

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Pappus Biology Coursework

PAPPUS BIOLOGY

COURSEWORK

YEAR 11

BY SHERYAR MAJID

Introduction and Planning

Pollination is the process of moving the pollen grain from the anther of a stamen to the stigma of a carpel. There are a few flowers that can self-pollinate all on their own, but this limits them to inbreeding. Most species rely upon some kind of pollination vector (as in wind and water) to accomplish pollination.

Animals:

Also known as the “smart bomb” or “magic bullet” vector, animals are probably the best and most commonly used means of pollination. The animal can do a number of things to accomplish pollination. It can:

Eat it, and then drop it

Eat it and then excrete it

Give it to their young, or another animal who will drop it or excrete it

Pick it up unknowingly and then drop it somewhere

Pick it up unknowingly and then drop it in the stigma

Animals are very effective because they can:

Remember where the flower is

Get to the flower without depending on others

Locate and sense the flowers easily through touch, sight, and smell

These are the three main reasons as to why animals are called the “magic bullet”, and “smart bomb.”

Apparatus:

        

For the practical: -

1 retort stand

2 clamps

1-meter stick

1 seed (if you are confident that you will not break any)

1 stopwatch

        

For recording the results: -

Lined paper

Graph paper

1 pair of scissors

1 calculator

Ruler

Pencil

Method:

1. Set up the apparatus for the practical

(Place boss on desktop,

Attach 1 clamp to the boss,

Attach the other clamp to the first

Clamp,

Attach meter stick towards second

Clamp)

2. Draw outline of the pappus onto

the graph paper. Measure the radius

with  ruler, and the work out the area

with a calculator

3. Drop seed form the top of the

meter stick.

4. Time how long it takes for

the pappus to reach the desktop

5. Repeat  numbers 3 and 4

five times

6. Cut a quarter of the pappus (as

 shown on the right)

Join now!

7. Repeat numbers 2 to 5.

8. Repeat 6, making sure the pappus will

look like the diagram on the right once

you have cut a quarter of it each time

9.  Record results

Fair Test:

In order to make this experiment a fair test, you will have to:

1. Make sure that you only use ONE seed, otherwise the reading will be faulty if you use a different seed during the experiment

2. Drop the seed at the same point from the meter stick.

From the diagram on the right, you ...

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