Life and Physical Sciences Flashcards
6 cards from real CAEC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Life and Physical Sciences flashcards as text
A student places a beaker of water on a hot plate and observes that the water at the bottom of the beaker gets hot and rises, while the cooler water at the top sinks to take its place. This process continues, creating a circular movement of water. Which method of heat transfer is primarily demonstrated in this scenario?
Answer: Convection
Convection is the transfer of heat through the movement of fluids (liquids or gases). In this scenario, the water is heated, becomes less dense, and rises. The cooler, denser water sinks to take its place, creating a convection current which distributes heat throughout the beaker.
Which of the following correctly describes the primary function of mitochondria within a eukaryotic cell?
Answer: To generate most of the cell's supply of adenosine triphosphate (ATP) through cellular respiration.
The mitochondrion is known as the 'powerhouse' of the cell. Its main function is to perform cellular respiration, a process that breaks down nutrients and turns them into adenosine triphosphate (ATP), the main energy-carrying molecule used to power the cell's metabolic activities.
In a food web, an organism that breaks down dead organic material, returning essential nutrients to the soil, is known as a:
Answer: Decomposer
Decomposers, such as bacteria and fungi, play a critical role in ecosystems by breaking down dead plants and animals. This process recycles nutrients, making them available for producers (like plants) to use, thus sustaining the ecosystem.
A chemical solution with a pH of 3 is considered to be:
Answer: Acidic
The pH scale measures how acidic or basic a substance is. The scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 indicates acidity, and a pH greater than 7 indicates a base. Since the solution has a pH of 3, it is acidic.
A person pushes a 50 kg box across a frictionless surface with a constant force, causing it to accelerate at 2 m/s². According to Newton's Second Law of Motion (F=ma), what is the net force applied to the box?
Answer: 100 N
Newton's Second Law of Motion states that the force (F) acting on an object is equal to the mass (m) of the object multiplied by its acceleration (a). In this case, F = 50 kg × 2 m/s² = 100 N. The unit for force is Newtons (N).
Which human body system is primarily responsible for transporting oxygen, nutrients, and hormones to cells throughout the body and removing waste products like carbon dioxide?
Answer: Circulatory System
The circulatory system, which includes the heart, blood, and blood vessels (arteries, veins, capillaries), is responsible for pumping and circulating blood. This circulation process delivers essential substances like oxygen and nutrients to all body cells and removes metabolic wastes.