Grade 7 Science Term 1 Comprehensive Revision

Practice fill-in-the-blank flashcards covering the core concepts of Biology Units 5–6, Chemistry Units 7–8, and Physics Units 6–7 from Grade 7 Science.

The word equation for aerobic respiration is: glucose + oxygen $\rightarrow$ __________ (+ energy).

carbon dioxide + water

Aerobic respiration takes place inside the part of the cell called the __________.

mitochondria

Oxygen moves from the alveoli into the surrounding blood capillaries by the process of __________.

diffusion

The yellow liquid that makes up $55\%$ of human blood is called __________.

plasma

The human trachea is held open to allow air to pass freely by rings of __________.

cartilage

During anaerobic respiration in human muscle cells, glucose is converted into __________.

lactic acid

After a few weeks of living or training at high altitude, the human body adapts by producing more __________.

red blood cells

Proteins are complex molecules built up from $20$ different building blocks called __________.

amino acids

A dietary deficiency in __________ leads to scurvy, causing bleeding gums and peeling skin.

vitamin C

In cigarette smoke, the poisonous gas that attaches to haemoglobin and reduces oxygen transport is __________.

carbon monoxide

Skeletal muscles are attached to bones by tough, non-stretching cords called __________.

tendons

According to the Body Mass Index (BMI) categories, a BMI between $30$ and $39.9$ is classified as __________.

obese

In an antagonistic muscle pair at the elbow joint, bending the arm requires the biceps to contract while the __________ relaxes.

triceps

The sub-atomic particle in the nucleus that has a relative mass of $1$ and a relative charge of $0$ is the __________.

neutron

An electron has a relative charge of $-1$ and a relative mass of __________.

$$\frac{1}{2000}$$

Geiger and Marsden's gold foil experiment showed that atoms consist mostly of empty space with a tiny, positively charged central __________.

nucleus

Atoms of the same element that contain the same number of protons but different numbers of neutrons are called __________.

isotopes

The total count of protons and neutrons in the nucleus of an atom is defined as the __________ number.

nucleon

Unlike impure mixtures, a pure substance melts and boils at a sharp, fixed __________.

temperature

In a distillation setup, steam cools and condenses back into liquid pure water inside the __________.

condenser

A solution that contains the maximum possible mass of solute dissolved at a given temperature is said to be __________.

saturated

When chlorine reacts with organic compounds dissolved in untreated water, it can form chemical byproducts called __________.

THMs

On a distance–time graph, the gradient of the line represents the __________.

speed

The standard SI unit for pressure is equivalent to $1\,\text{N/m}^2$ and is named the __________.

pascal

According to the principle of moments, a balanced see-saw has clockwise moments equal to __________ moments.

anticlockwise

The point beyond which an extended spring will suffer permanent deformation and not return to its original length is the __________.

elastic limit

Liquid pressure acts in all directions and increases directly with __________.

depth

The law of reflection states that the angle of incidence equals the angle of reflection, both measured relative to the __________.

normal

When a light ray enters an optically denser medium such as glass from air, it slows down and bends __________ the normal.

towards

Inside an optical medium, total internal reflection occurs whenever the angle of incidence is greater than the __________.

critical angle

When white light is dispersed by a prism, __________ light is refracted the most because it travels slowest in glass.

violet

The three primary colours of light are red, green, and __________.

blue

A light year is a unit of astronomical measurement defined as the __________ travelled by light in one year.

distance