Plants make their own food using sunlight. What is this process called?

Respiration Fermentation Photosynthesis Transpiration

During photosynthesis, what form of energy do plants convert into chemical energy?

Thermal energy from the soil Light (radiant) energy from the Sun Sound energy from the environment Electrical energy from lightning

Why do animals need to eat food?

To add mass to their bodies so they become heavier To obtain chemical energy stored in food molecules, which powers all life processes To absorb sunlight indirectly through the food chain To cool down their bodies by releasing cold energy

Cellular respiration is the process by which cells release energy from glucose. What are the main products of aerobic cellular respiration?

Glucose and sunlight Oxygen and protein Carbon dioxide, water, and energy (used to make ATP) Nitrogen gas and heat only

When you exercise vigorously, you feel warmer and you breathe faster. Which statement best explains both of these observations?

Your body is creating new energy from nothing because you need it Muscles are respiring faster, converting more chemical energy into kinetic energy and thermal energy, and needing more oxygen Your blood is heating up because it moves faster during exercise You breathe faster to blow out excess energy that builds up in your blood

In a simple food chain — grass → rabbit → fox — where did the energy in the fox ultimately come from?

The soil, which provides nutrients that contain energy The rabbit, which generates its own energy internally The Sun — via the grass that captured its light energy through photosynthesis The air, which is full of oxygen that contains energy

At each step in a food chain, some energy is 'lost'. Where does this energy go?

It disappears — it is destroyed in the process of digestion It is stored in the soil for use by plants later It is released as thermal energy (heat) that disperses into the environment It is reflected back into space as light

ATP (adenosine triphosphate) is described as the 'energy currency' of the cell. What does this mean?

It is the same as cash — living organisms buy energy from the environment It is the molecule that carries and delivers energy to wherever it is needed inside the cell It stores energy permanently until an organism dies It is the oxygen molecule used in respiration

A wolf eats a deer that ate grass. Which correctly summarises the original energy source and the chain of transformations?

Chemical energy (grass) → thermal energy (deer) → kinetic energy (wolf) Solar (radiant) energy → chemical energy (grass) → chemical energy (deer) → kinetic + thermal energy (wolf) Nuclear energy (Sun) → chemical energy (grass) → kinetic energy (deer and wolf) Thermal energy (Sun) → chemical energy (grass) → electrical energy (wolf's nervous system)

Why can't a food chain have hundreds of links — why do real food chains stop at four or five?

Because animals run out of space to live in after a few links Because organisms at the top of the chain are too large to have predators Because energy is lost as heat at each step, so after a few links there is too little energy left to support another predator Because sunlight is only strong enough to power three or four reactions before it is used up