f2 worksheet 4.4

Form 2 Science – Unit 4.1 : Photosynthesis

Form 2 Notes & Worksheet Unit 4.4 prepared by Ms Sue

1. Photosynthesis is a process that occurs in ____________________________, in which

________________ is made and ________________ is produced from _____________ and

_____________________________ in the presence of _________________________ and

_______________________.

2. ______________________________ is used to convert carbon dioxide and water into

______________________________.

3. The equation below shows the process of photosynthesis:

4. Plants use the energy from glucose for processes such as _________________ and

maintaining _________________________.

5. Excess glucose is converted into ________________ in some plants. This is then

transported to ______________________________ such as stems, roots, tubers and seeds.

Many plants convert glucose into ___________________ for storage.

________________________ is used to convert into

chemical energy _________________ is produced out after

the process

_____________________

and _____________ are

the raw materials needed

_________________ absorbs the light

energy from the Sun



LIGHT

1. Light is necessary for photosynthesis to take place. It serves as the source of _____________

for the green plants.

2. Based on the diagram below, a leaf is taken from a potted plant which has been put under

the hot sun for 3 hours. The leaf is then tested with iodine. What is the RESULT of this

experiment? Draw it out.

CHLOROPHYLL

1. Chlorophyll is the _____________________________ found in the ________________ of plants.

2. It ____________________________________ from the Sun or from a suitable light source and

enables the plant to make food.

3. The role of chlorophyll in photosynthesis can be demonstrated using a

____________________________________.

a. In this type of leave, only certain parts are _______________. These parts contain

chlorophyll.

b. Examples :

___________________________

___________________________



4. A variegated leaf from a plant is removed. Then it is tested with iodine for the presence of

starch. Draw out the result.

CARBON DIOXIDE & WATER

1. Carbon dioxide and water are the _____________________________ needed for

photosynthesis.

2. Carbon dioxide enters the leaves through the _________________ while water enters

through the ____________.

3. Diagram below shows an experiment conducted to test that carbon dioxide is needed for

photosynthesis. Complete the diagram and answer the questions that follow.

Alcohol

Iodine solution

Contains chlorophyll

Does not contain

chlorophyll

Turns to

_____________ Remains

_____________

Potassium hydroxide



a. Before the experiment, the plants are kept in dark for two days. Why?

____________________________________________________________________________

b. What is the function of potassium hydroxide?

____________________________________________________________________________

c. Name another substance that can be used to replace the potassium hydroxide.

____________________________________________________________________________

d. Which bell jar gives a positive result?

____________________________________________________________________________

The Importance of photosynthesis

1. Photosynthesis is important to maintain the ______________________ of an ecosystem.

2. The importance and role of photosynthesis are:

a. supplies food to _______________________

b. Enables ____________________________ to make their own food.

c. Regulates and maintains _________________________ content in the atmosphere.

d. Increases __________________ content in the atmosphere; this gas is used by

organisms for ________________________ as well as in the process of

combustion, rusting and decomposition.

CARBON CYCLE

1. Carbon is an important element present in all living organisms as the _______________ in

all living organisms are made up of carbon compound such as ________________________,

_________ and ________________.

2. Carbon cycle is a continuous cycle of processes by which carbon, in the form of



___________________________, is removed and restored in the air to maintain a constant

level.

3. Complete the diagram below.

___________________produces carbon

dioxide as it releases energy from food

___________________uses carbon dioxide to

make food



OXYGEN CYCLE

1. Oxygen is needed by all living organisms for _______________________. In fact. Carbon

cycle and oxygen cycle is interconnected.

2. Complete the diagram below.

f2 worksheet 4.4

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