life science

What is the Scientific Method?

A systematic approach used by scientists to investigate observations and answer questions. It involves observing, asking questions, forming hypotheses, experimenting, analyzing data, and drawing conclusions.

List the main steps of the Scientific Method.

1. Observation
2. Question
3. Hypothesis
4. Experiment
5. Analysis
6. Conclusion

What is a cell?

The basic structural and functional unit of all known organisms. All living things, like humans, plants, bacteria, and fungi, are made of cells.

Why are cells typically small?

Cells must remain small to maintain a large enough surface area-to-volume ratio, which allows for efficient exchange of nutrients, waste, and gases with their environment.

What is the Scientific Method?

A systematic approach used by scientists to investigate observations and answer questions. It involves observing, asking questions, forming hypotheses, experimenting, analyzing data, and drawing conclusions.

List the main steps of the Scientific Method.

1. Observation
2. Question
3. Hypothesis
4. Experiment
5. Analysis
6. Conclusion

What is a cell?

The basic structural and functional unit of all known organisms. All living things, like humans, plants, bacteria, and fungi, are made of cells.

Why are cells typically small?

Cells must remain small to maintain a large enough surface area-to-volume ratio, which allows for efficient exchange of nutrients, waste, and gases with their environment.

Compare and contrast animal and plant cells.

• Animal Cells (e.g., human cheek cell): Have a cell membrane, cytoplasm, nucleus, and mitochondria. Do not have a cell wall or chloroplasts.
• Plant Cells (e.g., onion cell): Have all animal cell components PLUS a cell wall (for support), chloroplasts (for photosynthesis), and a large central vacuole.

What is the key difference between prokaryotic and eukaryotic cells?

• Prokaryotic Cells (e.g., bacteria): Simpler, smaller, no true nucleus (genetic material is in the cytoplasm), and no membrane-bound organelles.
• Eukaryotic Cells (e.g., human, plant, fungi cells): Larger, more complex, have a true nucleus (containing genetic material), and have membrane-bound organelles (like mitochondria, chloroplasts in plants).

What is Diffusion?

The net movement of particles (molecules/ions) from an area of higher concentration to an area of lower concentration, down a concentration gradient. It does not require energy.

Provide examples of diffusion.

• Gases: Oxygen diffusing from high concentration in lungs to low concentration in blood.
• Scent: The smell of perfume spreading across a room.

What is Osmosis?

The net movement of water molecules across a selectively permeable membrane from an area of higher water concentration (lower solute concentration) to an area of lower water concentration (higher solute concentration). It is a type of diffusion for water.

Provide examples of osmosis.

• Plant roots: Absorb water from the soil by osmosis.
• Red blood cells: Swell up or shrink depending on the water concentration of the surrounding solution.

What is Active Transport?

The movement of particles across a cell membrane against their concentration gradient (from low to high concentration), requiring energy (ATP) from the cell.

Provide examples of active transport.

• Plant root cells: Absorb mineral ions (like nitrates) from the soil, even when the concentration is lower in the soil than in the root cells.
• Human small intestine: Absorption of glucose from the gut into the bloodstream, even when glucose concentration is higher in the blood.

What are important rules for drawing biological diagrams?

• Use a sharp, HB pencil.
• Draw clear, continuous lines. No sketching!
• Use a ruler for label lines.
• Label lines should not cross.
• Include a title and magnification (if known).

What is an Independent Variable?

A factor that is changed or manipulated by the experimenter (e.g., amount of water given to a plant).

What is a Dependent Variable?

The factor that is measured or observed as a result of the changes made to the independent variable (e.g., plant height).

What are Controlled Variables?

Factors that are kept the same throughout the experiment to ensure a fair test (e.g., type of plant, temperature, light exposure).

How do you write an Aim for an experiment?

A clear statement describing the purpose of the experiment or what the investigation aims to find out. Usually starts with 'To investigate…' or 'To determine…'.

How do you write a Hypothesis?

A testable prediction or educated guess about the outcome of an experiment. It is often written as an 'If…, then…, because…' statement.

What should be included in a Conclusion?

Summarizes the findings, states whether the hypothesis was supported or rejected, and explains the results. It should refer back to the aim and hypothesis.

What are the key features of a good data table?

• Clear title.
• Labeled columns and rows.
• Units included in column/row headers.
• Data neatly organized.

When and how do you use a Line Graph?

• Used to show continuous data and trends over time or across a range of values.
• Axes labeled with quantities and units.
• Points plotted accurately and connected by lines.

• Used to compare discrete categories or groups.
• Axes labeled.
• Bars are of equal width and separated by gaps.
• Height of bar represents