Test: Fractions and Percentages - Year 5 MCQ

The theory of evolution by natural selection, proposed by Charles Darwin, is significant because it explains how species adapt and evolve over time through the process of natural selection. Organisms that are better adapted to their environment tend to survive and reproduce, passing on advantageous traits to future generations.

Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy, specifically glucose, using carbon dioxide and water. This process also produces oxygen as a byproduct, which is essential for the survival of most life forms on Earth.

Opportunity cost is a crucial concept in economics that refers to the value of the next best alternative that is given up when a choice is made. For instance, if a person decides to spend time studying instead of working, the opportunity cost is the income they could have earned during that time.

The greenhouse effect refers to the trapping of heat by greenhouse gases, such as carbon dioxide and methane, in the Earth's atmosphere. This natural process is essential for maintaining a habitable climate, but human activities have intensified it, leading to global warming.

Natural gas is not a type of renewable energy; it is a fossil fuel that contributes to greenhouse gas emissions. In contrast, wind energy, hydropower, and geothermal energy are sustainable sources that can be replenished naturally.

Solar energy is an example of a renewable energy source. It is derived from the sun's rays and can be harnessed using solar panels. Unlike fossil fuels, solar energy is sustainable and has a minimal environmental impact when used.

The scientific method serves as a systematic approach for investigating observations and answering questions. It involves steps such as making observations, forming a hypothesis, conducting experiments, and drawing conclusions based on empirical evidence. This method is vital for ensuring that research is conducted in an organized and unbiased manner.

The primary function of the immune system is to defend the body against pathogens, such as bacteria, viruses, and parasites. It detects and responds to foreign invaders, providing protection and helping to maintain overall health.

The primary goal of the United Nations (UN) is to promote international cooperation and maintain peace and security among nations. Founded in 1945, the UN works to address global challenges and foster dialogue between countries to prevent conflict.

One of the core characteristics of living organisms is their ability to reproduce. This can occur through various methods, including sexual and asexual reproduction, and is essential for the continuation of species. While not all living things move independently, all exhibit some form of reproduction.

The primary objective of peer review in the scientific community is to ensure the integrity and quality of research. By having experts evaluate a study before publication, the process helps to validate the results and methodology, maintaining high standards in scientific literature.

The Declaration of Independence is known for establishing the principles of freedom and democracy in the United States. Adopted on July 4, 1776, it asserts the rights of individuals and justifies the colonies' separation from British rule, emphasizing liberty and equality.

The main function of the circulatory system is to transport nutrients and oxygen to cells throughout the body while removing waste products such as carbon dioxide. This system is vital for maintaining homeostasis and supporting cellular processes.

The primary function of the respiratory system is to facilitate gas exchange, specifically the intake of oxygen and the expulsion of carbon dioxide. This process is vital for cellular respiration, which provides energy for the body’s functions.

Carbon is an essential element for the formation of proteins, as it forms the backbone of amino acids, the building blocks of proteins. Proteins are critical for numerous biological functions, including catalyzing metabolic reactions and providing structural support.

A significant consequence of deforestation is the increased levels of carbon dioxide in the atmosphere. Trees absorb carbon dioxide during photosynthesis, and their removal contributes to higher greenhouse gas concentrations, impacting climate change.

DNA (deoxyribonucleic acid) serves the primary role of storing genetic information in living organisms. It contains the instructions necessary for the development, functioning, and reproduction of all known life forms, thus playing a crucial role in heredity.

Cultural diffusion refers to the process through which cultural beliefs, practices, and items are spread from one culture to another. This can occur through various means, including trade, migration, or conquest, leading to a blending of cultural practices and ideas.

Biodiversity refers to all of the above: the number of species in a specific area, the variety of ecosystems present, and the genetic variation within those species. High biodiversity is crucial for ecosystem resilience and overall health of the environment.

A primary characteristic of democracy is the participation of citizens in decision-making processes, typically through voting in elections. Democracies are built on the principles of representation and accountability, allowing citizens to influence government and policy.