Chapter 4
Tell the definition of sensitivity and movement for both living things.
sensitivity : living organisms are sensitive to changes going on around them.
Movement : living organisms can move and response to the environment.
How is Centrifugation done
Centrifugation is used to separate substances with different densities.
In centrifugation, a mixture is spun at high speed, causing denser substances to settle at the bottom of a container.
How Do Particles Behave When Sound is Generated?
When an object vibrates, it pushes against nearby air particles. These particles bump into other nearby particles, creating a chain reaction.
What does ammeter do in a cell?
Tell the scientific name for a horse and a donkey plus tell the name of their offspring.
Mules: The offspring of a male donkey and a
female horse
donkey : Equus africanus asinus
horse :Equus ferus caballus
❖ Why Use Indicators?
1. Identify Acids and Bases: By changing color, indicators show us if a solution is acidic, basic, or neutral.
2. Conduct Experiments: In scientific experiments, indicators help in observing chemical reactions and understanding the results.
What is the use of ultrasound in medicine?
Doctors use a special kind of echo called ultrasound to see inside the human body.
It works similarly to sonar but uses very high-frequency sound waves.
What are the advantages of circuit diagram compared with pictures
Circuit diagrams are easier to draw.
The components have standard symbols
Wires are drawn with straight lines, which is easy to interpret.
What is a identification key?
➢ Identification keys are tools used to help identify and classify organisms
or objects.
➢ They provide a series of choices that lead to the correct identification of a
species or item.
➢ Scientists, especially biologists, use identification keys to classify plants
and animals.
➢ Hikers and nature enthusiasts use them to identify plants and animals
they encounter in the wild.
What is the melting point of copper?
1085 degree Celsius
How many years ago pangea was present?
225 million years ago
Role of electrons
Electrons are negatively charged particles.
➢ They move from the negative to the positive terminal. This is opposite to the direction of the current flow
➢ This movement creates an electric current.
➢ The flow of electrons in a circuit is called current.
Tell the fullform of DNA and RNA.
DNA - Deoxyribonucleic acid
RNA - Ribonucleic acid
Tin : White Metal
Bronze : Reddish brown not as bright as brass
What is a volcano?
A volcano is an opening in the Earth's crust where molten rock, ash, and gases can escape. Volcanoes form when magma from the Earth's interior pushes through the surface. They can erupt explosively or flow gently.
What happens to a circuit when you add a cell (battery) to it?
When you add a cell (battery) to a series circuit:
■ The total voltage increases.
■ Lights become brighter because more electrical energy is available.
Reasons for Breeding Between Different Species
➢ Availability of mates: If there are not enough mates available of their species.
➢ Environmental changes: In some cases, animals may adapt to new environments where different species are present.
Tell the Hazard Warning Labels
Explosive, Flammable, Oxidising, Corrosive, Toxic, Hazardous to the environment, Health Hazard, Serious Health Hazard
150 million years ago, which 2 continents were there?
Laurasia, Gondawana
Name 4 reactions with water
1. Potassium and Water: Potassium reacts explosively with water, producing potassium hydroxide and hydrogen gas.
2. Sodium and Water: Sodium reacts with water, creating sodium hydroxide and hydrogen gas.
3. Calcium and Water: Calcium reacts with water to form calcium hydroxide and hydrogen gas.
4. Magnesium and Water: Magnesium reacts with water to form magnesium hydroxide and hydrogen gas.