Science Review: Forces, Simple Machines, Scientific Investigations, and Cell Biology

Comprehensive vocabulary flashcards generated from lecture notes on forces, gravity, simple machines, scientific investigation variables, microscope components, cell biology, cellular respiration, photosynthesis, and biological organization.

Force

A push, pull or twist that can change an object's shape (squashing or stretching), direction, or motion (speeding up, slowing down, or stopping).

Contact Force

A force where objects must touch, such as friction, buoyancy, or push/pull.

Non-Contact Force

A force where objects don't need to touch, such as gravity, magnetism, or static electricity.

Balanced Forces

Equal forces acting in opposite directions resulting in a net force of $0\,\text{N}$, where motion does not change.

Unbalanced Forces

Forces that are not equal, resulting in a net force that is not $0\,\text{N}$, which can cause an object to speed up, slow down, or change direction.

Static Electricity

A non-contact force where objects become electrically charged as electrons move between them, causing like charges to repel and opposite charges to attract.

Mass

The amount of matter in an object, measured in kilograms ($\text{kg}$), which stays the same wherever you go.

Weight

The force of gravity acting on an object, measured in newtons ($\text{N}$), which can change on different planets.

Weight Formula

The mathematical formula $F = mg$, where $F$ is weight force in newtons ($\text{N}$), $m$ is mass in kilograms ($\text{kg}$), and $g$ is gravitational acceleration in newtons per kilogram ($\text{N/kg}$).

Gravitational Acceleration on Earth

The gravitational acceleration constant $g$ on Earth, which equals $9.8\,\text{N/kg}$.

Magnetic Field

The area around a magnet where magnetic forces act.

Simple Machine

A device that makes work easier by changing the size or direction of a force.

The 6 Simple Machines

The six standard mechanical devices: Lever, Inclined plane, Wedge, Screw, Wheel & axle, and Pulley (remembered by LIWSWP: Little Iguanas Want Some Water Please).

Independent Variable

The factor or variable that you change in a scientific investigation ("I change it").

Dependent Variable

The variable that you measure to collect data in a scientific investigation ("D=Data").

Controlled Variables

The variables you keep the same in a scientific investigation to make it a fair test.

Aim

A statement that says what you are investigating in a scientific experiment.

Trend

A statement that describes what happens to the results in a scientific experiment or graph.

Cell Theory

The three main biological principles: 1. All living things are made of cells, 2. Cells are the basic unit of life, 3. All cells come from pre-existing cells.

Total Magnification Formula

The rule for microscope magnification: $\text{Total magnification} = \text{eyepiece} \times \text{objective lens}$.

Coarse Focus

The microscope part used for large focus adjustment.

Fine Focus

The microscope part used for small focus adjustment.

Nucleus

The organelle that controls the cell and contains DNA.

Cytoplasm

The jelly-like substance in a cell where many chemical reactions happen.

Cell Membrane

The structure that controls what enters and leaves the cell.

Cell Wall

A structure found in plant cells that provides support and strength.

Chloroplast

The organelle in plant cells and some protists where photosynthesis happens.

Vacuole

An organelle that stores water and other substances; plant cells have a large central vacuole, while animal cells usually have small vacuoles.

Mitochondria

The organelle where cellular respiration occurs and energy is released.

Unicellular Organism

An organism made of only one cell, such as bacteria or amoeba.

Multicellular Organism

An organism made of many cells, such as humans, trees, or dogs.

Cellular Respiration

The process in mitochondria that releases energy for cells, represented by the word equation: $\text{Glucose} + \text{Oxygen} \rightarrow \text{Carbon dioxide} + \text{Water} + \text{Energy}$.

Photosynthesis

The process in chloroplasts where plants use light energy to make glucose, represented by the word equation: $\text{Carbon dioxide} + \text{Water} \rightarrow \text{Glucose} + \text{Oxygen}$.

Specialised Cell

A cell that has a particular structure that helps it perform a specific job, such as a muscle cell or skin cell.

Levels of Organisation

The structural order of multicellular organisms: $\text{Cells} \rightarrow \text{Tissues} \rightarrow \text{Organs} \rightarrow \text{Organ systems} \rightarrow \text{Organism}$ (remembered by: Cats Take Our Old Orange).