Science 5 Flashcards
What is the primary gas found in Earth’s atmosphere?
Nitrogen is the primary gas found in Earth’s atmosphere, making up about 78%.
Define ‘ecosystem’.
An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system.
What is the function of mitochondria in a cell?
Mitochondria are known as the powerhouses of the cell, generating most of the cell’s supply of adenosine triphosphate (ATP), used as a source of chemical energy.
How do earthquakes occur?
Earthquakes occur due to the movement of tectonic plates beneath the Earth’s surface.
What are renewable energy sources? Give two examples.
Renewable energy sources are those that can be replenished naturally. Examples include solar energy and wind energy.
Explain the difference between speed and velocity.
Speed is the rate at which an object covers distance, whereas velocity is speed in a given direction.
What is the purpose of the ozone layer?
The ozone layer absorbs and scatters the majority of the sun’s ultraviolet radiation, protecting life on Earth from harmful UV rays.
Describe what a vaccine does in the human body.
A vaccine stimulates the body’s immune system to recognize the agent as a threat, destroy it, and remember it, so the immune system can more easily recognize and destroy any of these microorganisms that it encounters later.
What are the three states of matter?
The three states of matter are solid, liquid, and gas.
How is a rainbow formed?
A rainbow is formed when sunlight is refracted, or bent, and then scattered off water droplets from rain in the atmosphere.
What is a chemical reaction?
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.
What are the primary components of DNA?
The primary components of DNA are four types of nitrogen bases: adenine (A), cytosine (C), guanine (G), and thymine (T).
Explain the role of decomposers in an ecosystem.
Decomposers break down dead or decaying organisms, and in doing so, they carry out the natural process of decomposition.
What is the difference between a hypothesis and a theory?
A hypothesis is a proposed explanation for a phenomenon, while a theory is a thoroughly tested and confirmed explanation for a phenomenon.
Define ‘acid rain’ and its effects.
Acid rain is rain with higher levels of acid than normal, often caused by pollution. It can harm forests, soils, and aquatic life in rivers and lakes.
