Year 8 Science Digital Flashcard

Front

Which part of the cell controls its activities?

Back

Nucleus

Answer explanation

The nucleus is the control center of the cell, regulating its activities by storing genetic information and coordinating cell functions such as growth, metabolism, and reproduction.

Front

Which cell structure is found only in plant cells?

Back

Cell wall

Answer explanation

The cell wall is a structure found only in plant cells, providing support and protection. In contrast, the nucleus, cell membrane, and mitochondria are present in both plant and animal cells.

Front

Which unit is used to measure force?

Back

Newtons

Answer explanation

Force is measured in Newtons, which is the standard unit in the International System of Units (SI). Grams and kilograms measure mass, while litres measure volume, making Newtons the correct choice for force.

Front

Which of the following is a non-contact force? Friction, Air resistance, Gravity, Tension

Back

Gravity

Answer explanation

Gravity is a non-contact force that acts at a distance, pulling objects toward each other without physical contact. In contrast, friction, air resistance, and tension require contact between surfaces or objects.

Front

Where does fertilisation usually take place in humans?

Back

Fallopian tube

Answer explanation

Fertilisation in humans typically occurs in the Fallopian tube, where the sperm meets the egg after ovulation. The ovary produces the egg, but fertilisation itself happens in the Fallopian tube before the embryo moves to the uterus.

Front

Which of these is a male reproductive cell? Egg, Sperm, Embryo, Zygote

Back

Sperm

Answer explanation

The male reproductive cell is the sperm, which is responsible for fertilizing the female egg. The egg is the female reproductive cell, while the embryo and zygote are stages of development after fertilization.

Front

What do you call a substance that dissolves in a liquid?

Back

Solute

Answer explanation

A substance that dissolves in a liquid is called a solute. The liquid that does the dissolving is known as the solvent, while the combination of solute and solvent forms a solution.

Front

Which method is best for separating salt from salt water?

Back

Evaporation

Answer explanation

Evaporation is the best method for separating salt from salt water because it allows the water to turn into vapor, leaving the salt behind as a solid. Filtering and sieving do not effectively separate dissolved substances, and magnetism is not applicable.

Front

Which planet is closest to the Sun?

Back

Venus

Answer explanation

Venus is the second planet from the Sun, while Earth is the third. Therefore, Venus is closer to the Sun than Earth.

Front

What force keeps the planets in orbit around the Sun?

Back

Gravity

Answer explanation

The force that keeps the planets in orbit around the Sun is gravity. It is the attractive force between the Sun and the planets that maintains their orbits, preventing them from drifting away into space.