14 Questions
What is the term used to describe the passing of traits from one generation to the next?
Heredity
What type of variation is shown by characteristics such as height and body mass?
Continuous variation
What is the term used to describe the differences in features among individuals of a species?
Variations
What type of energy is stored inside a living thing, in a battery, in food, and in fuels?
Chemical energy
What is the relationship between the strength of vibration and sound energy?
The stronger the vibration, the more sound energy it gives out
What type of variation is usually affected only by DNA?
Discontinuous variation
What type of energy does an object possess due to its motion?
Kinetic energy
What is the unit of energy that is equivalent to 1000 joules?
Kilojoule
What is the law that states that energy cannot be created or destroyed, only converted from one form to another?
Law of Conservation of Energy
What is the percentage of oxygen in the air we breathe?
21%
What type of energy is stored in an object when it is raised to a higher position?
Potential energy
What is the term for the amount of energy an object has due to its motion and position?
Mechanical energy
What is the process by which light energy is converted into chemical energy?
Photosynthesis
What is the formula for calculating the efficiency of a device?
(Useful energy output ÷ Total energy input) x 100%
Study Notes
Heredity and Variations
- Heredity refers to the passing of traits or characteristics from one generation to the next.
- Traits are the features each generation inherits from their parents.
- Variations are the differences in features among individuals of a species.
- There are two types of variations: continuous and discontinuous.
Continuous Variation
- Shows a continuous range of differences.
- Features include height, body mass, hand span, and IQ.
- Affected by both DNA and environment.
- Presented using a histogram.
Discontinuous Variation
- Shows clear-cut differences.
- Features include ear lobes, tongue rollers, hairline, and blood group.
- Usually affected by DNA only.
- Presented using a bar chart.
Energy
- Sound energy is produced when an object vibrates.
- The strength of vibration is directly related to the sound energy produced.
- Types of energy include:
- Chemical energy: stored inside living things, batteries, food, and fuels.
- Light energy: obtained from sources like the sun or light bulbs.
- Thermal energy/heat: an object with a higher temperature than its surroundings will give out heat.
- Kinetic energy: moving objects have kinetic energy, related to speed and mass.
- Potential energy: stored energy when an object is raised to a higher position or stretched/compressed.
Units of Energy
- Joules (J): a unit of energy, e.g., a lamp uses 18000J in one hour.
- Kilojoules (kJ): 1 kJ = 1000 J.
- Calorie (cal): measures energy value of food.
- Kilocalories (kcal): 1 kcal = 1000 cal.
Energy Conversion
- Energy can be converted from one form to another, but cannot be created or destroyed (Law of Conservation of Energy).
- Examples of energy conversion: kinetic to potential, chemical to light, and more.
- Efficiency: (Useful energy output ÷ total energy input) x 100%.
Matter
- Matter is around us and has two properties: mass and occupies space.
- Things that are matter: solid, liquid, gas, air.
- Things that are not matter: energy, heat, sound, force, rainbow, gravity.
- Air is a type of matter that takes up space and has mass.
Air
- The atmosphere is the layer of air on Earth.
- Composition of air: Nitrogen (78%), Oxygen (21%), Carbon dioxide (0.03%), Noble gases (0.9%), Water vapour and other gases (0.07%).
- Gases in air have various uses.
Learn about heredity, the passing of traits from one generation to the next, and variations that occur in a species, including continuous and discontinuous variations.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
