yr7 bio/phys

Nucleus

Organelle that controls cell activities and contains genetic information.

Cell membrane

Structure that controls which substances enter and exit a cell.

Mitochondria

Organelles that release energy through the process of respiration.

Cytoplasm

Jelly-like substance where the chemical reactions of a cell take place.

Cell wall

Rigid outer layer in plant and bacterial cells that supports and protects the cell.

Chloroplasts

Organelles in plant cells that absorb sunlight to produce glucose through photosynthesis.

Vacuole

Storage space within plant cells.

Bacterial DNA

Large, coiled loop of genetic material in the cytoplasm of a bacterium that controls cell functions.

Plasmid

Small loop of DNA in bacteria that provides resistance to substances such as antibiotics.

Flagellum

Tail-like structure that enables movement in some bacteria.

Tissue

Group of similar cells working together to perform a specific function.

Diffusion

Random movement of particles from an area of high concentration to an area of low concentration.

Nutrients

Substances required by organisms to survive and grow, such as carbohydrates, proteins, fats, vitamins, and minerals.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs.

Vertebrate

Animal that possesses a backbone.

Mammals

Warm-blooded vertebrates that have hair or fur, give birth to live young, and produce milk to feed their offspring.

Producer

Organism (usually a green plant) that synthesizes its own food.

Apex predator

Animal at the top of a food chain with no natural predators.

Competition

Interaction between organisms struggling for limited resources like food, water, territory, or mates.

Adaptation

Trait or characteristic that enables an organism to survive in its specific environment.

Photosynthesis word equation

$$\text{Carbon dioxide} + \text{water} \xrightarrow{\text{light/chlorophyll}} \text{glucose} + \text{oxygen}$$

Energy

Property measured in $\text{Joules}\ (\text{J})$ that cannot be created or destroyed, only transferred.

Power

Rate at which energy is transferred, measured in $\text{Watts}\ (\text{W})$.

Force

Push or pull exerted on an object, measured in $\text{Newtons}\ (\text{N})$.

Newtonmeter

Piece of equipment used to measure force.

Friction

Contact force between two surfaces opposing motion that can increase thermal energy.

Drag (air resistance)

Force that opposes the motion of an object traveling through the air.

Balanced forces

Condition where opposing forces are equal, resulting in a constant speed or a stationary state.

Moment

Turning effect of a force.

Extension

Increase in an object's length caused by pulling forces.

Compression

Decrease in an object's length caused by squashing forces.

Elastic behavior

Ability of an object to return to its original shape once deforming forces are removed.

Inelastic behavior

Tendency of an object to remain deformed and not return to its original shape after forces are removed.

Streamlined

Shape designed to reduce air resistance or drag.

Chemical energy store

Energy stored in food, fuels (such as coal, oil, gas), or batteries.

Kinetic energy store

Energy stored in moving objects.

Gravitational potential energy store

Energy stored due to an object's height above the ground.

Thermal energy store

Energy stored due to an object's temperature.

Formula for magnification

$$\text{Magnification} = \frac{\text{Image size}}{\text{Actual size}}$$

Formula for actual size

$$\text{Actual size} = \frac{\text{Image size}}{\text{Magnification}}$$

Formula for power

$$\text{Power} = \frac{\text{Energy transferred}}{\text{Time}}$$

Formula for Body Mass Index (BMI)

$$\text{BMI} = \frac{\text{Mass}}{(\text{Height})^2}$$

Units for weight and mass

Weight is measured in $\text{Newtons}\ (\text{N})$; mass is measured in $\text{kilograms}\ (\text{kg})$ or $\text{grams}\ (\text{g})$.

Independent variable

Variable that is intentionally changed or manipulated by the investigator.

Control variable

Variable kept constant during an experiment to ensure a fair test.

Proportional relationship on a graph

Relationship represented by a straight line passing through the origin $(0,0)$.

Microscope practical steps

1. Place the slide on the stage. 2. Select the lowest power objective lens. 3. Look through the eyepiece. 4. Use the coarse focus wheel to locate the specimen, then the fine focus wheel to refine image clarity.

Measuring energy in food steps

1. Measure the starting temperature of a set volume of water in $^{\circ}\text{C}$. 2. Secure a $1\,\text{g}$ food sample on a needle. 3. Light the food sample and hold it directly under a test tube of water. 4. Record the final temperature of the water and calculate the change.

Friction investigation steps

1. Place a block on a ramp. 2. Gradually incline the ramp until the block begins to slide. 3. Measure the height of the ramp in $\text{cm}$. 4. Repeat with different surface materials to compare levels of friction.