Science Form 3

Question 1

What is photosynthesis?

Answer 1

The process by which plants make their own food

Question 2

In photosynthesis, what are three factors plants use?

Answer 2

Water which they get from soil
Carbon dioxide, which they get from air
Energy which they get from sunlight

Question 3

What is chlorophyll?

Answer 3

A green pigment found inside the cells of leaves

Question 4

What does chlorophyll capture?

Answer 4

Sunlight

Question 5

What is the energy from sunlight used for?

Answer 5

It is used to make a chemical reaction with water and carbon dioxide

Question 6

What are the two new substances from the chemical reaction?

Answer 6

Glucose and oxygen (glucose/ food for plant) (oxygen/ diffuses form stomata)

Question 7

What is the word equation for photosynthesis?

Answer 7

Water + carbon dioxide ——> glucose+ oxygen

Question 8

Where does photosynthesis takes place?

Answer 8

In the chloroplast

Question 9

What is stomata?

Answer 9

Small holes in the foreskin of a leaf which allows gases to diffuse in and out of the leaf.

Question 10

What are the minerals we need for Plant growth?

Answer 10

Nitrogen, phosphorus , potassium, magnesium

Question 11

What is nitrogen needed for and what can a lack of it cause?

Answer 11

1.For making proteins.
2.Leads to stunted growth and yellowing

Question 12

What is phosphorus needed for and what can a lack of it cause?

Answer 12

1. For making roots.
2. Excessive greening and poor root growth.

Question 13

What is potassium needed for and what can a lack of it cause?

Answer 13

1. For making flowers and fruits.
2. Yellow leaves with dead spots.

Question 14

What is magnesium needed for and what can a lack of it cause?

Answer 14

1. To make chlorophyll.
2. Veins look green but leaf tissue looks yellow

Question 15

Where is glucose stored?

Answer 15

As a starch in leaves

Question 16

What is the equation for respiration?

Answer 16

Glucose + oxygen ——> carbon dioxide + water

Question 17

What is the carbon cycle?

Answer 17

The carbon cycle shows how carbon changes form when moving in an ecosystem

Question 18

What is combustion?

Answer 18

Burning fossil fuels

Question 19

What is respiration?

Answer 19

Processed by which animals breakdown nutrients to release energy

Question 20

What is feeding?

Answer 20

Ingestion of food and nutrients

Question 21

What does decomposition?

Answer 21

Decay of dead animals or plants

Question 22

What is an atomic number?

Answer 22

Tells you how many protons and elements contains

Question 23

What is a mass number?

Answer 23

How many protons and neutrons each element has in total

Question 24

How do you find the number of electrons?

Answer 24

You minus the mass number with the atomic number

Question 26

What does inert mean?

Answer 26

It means it’s unreactive

Question 27

What happens if an element loses an electron?

Answer 27

The elements will become positive Ex: Cl

Question 28

What happens if an element gains an electron?

Answer 28

It will become negative Ex: Cl-

Question 29

What is an ionic compound?

Answer 29

When a metal reacts with a nonmetal

Question 30

What is a pathway of water?

Answer 30

Soil - root hair cell- xylem- leaves

Question 31

What is a xylem and what does it do?

Answer 31

2.Transport water and minerals from the roots to the leaves. 1. It is situated in the stem.

Question 32

What is present in a diagram of a root cell?

Answer 32

Nucleus cytoplasm cell membrane cell wall, and vacuole containing cell sap

Question 33

What is transpiration?

Answer 33

It is the process by which the plant will loose water vapor through the leaves to cool itself

Question 34

How does water vapor diffuse out of the stomata?

Answer 34

Water is heated and changes to water vapor and evaporates through the pores(stomata)

Question 35

What is a covalent bond?

Answer 35

A link formed when atoms share electrons to form a molecule

Question 36

What is intra molecular forces?

Answer 36

Strong covalent bond forces. (Within the molecule)

Question 37

What are intermolecular forces?

Answer 37

Outside and a weak force

Question 38

What are macromolecules?

Answer 38

Large structure, e.g. diamond

Question 39

What is lattice?

Answer 39

Well, organized molecules, e.g. sodium chloride crystals

Question 40

What are ionic substances, melting, and boiling points?

Answer 40

Ionic substances have very high melting boiling points. (This is because there are very strong electrostatic forces holding ions together.)

Question 41

What are covalent substances, melting, boiling points?

Answer 41

Covalent substances made from simple molecules, have low melting points and boiling points because although the forces holding the molecules together are strong the forces between the molecular forces are weak.