AQA GCSE Trilogy Physics and Biology: Energy and Photosynthesis Retrieval Practice

Practice retrieval flashcards covering AQA Trilogy GCSE Physics P1 (Energy Stores, Transfers, Conservation, Work Done, Power, Efficiency, Specific Heat Capacity) and Biology (Photosynthesis Reaction, Limiting Factors, Leaf Anatomy, Inverse Square Law).

In physics, a __________ is defined as an object or group of objects.

system

The law of conservation of energy states that energy can be transferred usefully, stored, or dissipated, but cannot be __________.

created or destroyed

When energy in a system is described as 'wasted', it means only some energy is usefully transferred, with the rest lost to the surroundings as __________.

heat

Two common methods used to reduce unwanted energy transfers are __________ to reduce heat loss and lubrication to reduce friction.

insulation

Lubrication reduces unwanted energy transfers in mechanical systems by reducing __________.

friction

The energy store associated with a moving object, such as a car, is __________ energy.

kinetic

Food, chemical batteries, and fuels are all examples of objects that store __________ potential energy.

chemical

A stretched or compressed spring is an example of an object storing __________ potential energy.

elastic

The four pathways by which energy can be transferred are heating, electrical current, radiation, and __________.

mechanical forces

Another name for 'work done' in physics is __________.

energy transferred

One Joule of energy is defined as the work done when a force of one newton causes a displacement of __________.

$$1\,\text{m}$$

In the kinetic energy formula $E_k = \frac{1}{2}mv^2$, the speed or velocity ($v$) is measured in __________.

$$\text{m/s}$$

In the gravitational potential energy formula $E_p = mgh$, gravitational field strength ($g$) is measured in __________.

$\text{N/kg}$ or $\text{m/s}^2$

In the specific heat capacity equation $\Delta E = mc\Delta\theta$, the unit for specific heat capacity ($c$) is __________.

$$\text{J}/(\text{kg}\,{^\circ}\text{C})$$

Power is defined as the rate at which energy is transferred, or the rate at which __________.

work is done

One Watt is defined as an energy transfer of __________.

$$1\,\text{joule per second}$$

Efficiency is calculated as useful power output divided by __________.

total power input

The value for efficiency has no units and is expressed as a __________.

decimal or %

The word equation for photosynthesis is carbon dioxide + water $\rightarrow$ __________ + oxygen.

glucose

Carbon dioxide enters the plant for photosynthesis through the __________ from the surrounding air.

stomata

Water required for photosynthesis is taken up through the __________ in the soil.

roots

The sub-cellular structures inside plant cells that carry out photosynthesis are the __________.

chloroplasts

Photosynthesis is classified as an endothermic reaction because it __________ from the surroundings.

takes in energy

The three main limiting factors affecting the rate of photosynthesis are light intensity, temperature, and __________.

carbon dioxide

The other limiting factor that follows the exact same curve shape as light intensity on the rate of photosynthesis graph shown is __________.

carbon dioxide

Unlike light intensity and carbon dioxide, the temperature graph does not plateau; its rate rapidly declines after reaching an optimum because the enzymes __________.

denature

According to the inverse square law ($\text{Light intensity} \propto \frac{1}{\text{distance}^2}$), if the distance between a plant and the light source is doubled, the light intensity is __________.

quartered

Plants use the glucose produced during photosynthesis for respiration, to produce starch for storage, and to make __________ for cell walls.

cellulose

In a leaf, the epidermal tissues are adapted for photosynthesis by being __________ to let light pass through.

transparent

The palisade mesophyll layer of a leaf is specialized for photosynthesis because it contains __________.

lots of chloroplasts

The spongy mesophyll layer in a leaf contains __________ to allow gases to diffuse in and out of cells.

air spaces

The opening and closing of stomata are controlled by specialized cells called __________.

guard cells

In commercial greenhouses and agriculture, controlling limiting factors allows growers to maximise __________ efficiently.

crop yield