Comprehensive GCSE Biology: Cell, Organisation, Infection, Bioenergetics, Inheritance & More

What are some reasons why the perception of risk differs from measured risk?

Perception of risk can differ due to factors such as voluntary vs imposed risks, familiar vs unfamiliar risks, and visible vs invisible hazards.

How does the peer review process contribute to scientific claims?

Peer review helps detect false claims and establishes a consensus on which claims are regarded as valid.

Why is peer review important in communicating scientific results?

Peer review ensures the validity of results and helps communicate findings accurately to a range of audiences.

What is a potential issue with scientific reports in popular media?

Reports in popular media are not subject to peer review and may be oversimplified, inaccurate, or biased.

What is a hypothesis in scientific research?

A hypothesis is a proposed explanation for a set of observations or data.

How can scientific theories be used in hypothesis development?

Scientific theories and explanations can be used to develop hypotheses based on existing knowledge.

What should a well-designed practical procedure accomplish?

A well-designed practical procedure should effectively achieve its specified purpose.

What is the significance of manipulating and controlling variables in experiments?

Manipulating and controlling variables is essential to ensure that the experiment tests the intended hypothesis accurately.

What is the independent variable in an experiment?

The independent variable is the one that is changed or selected by the investigator.

What is the dependent variable in an experiment?

The dependent variable is the one that is measured for each change in the independent variable.

What are control variables in an experiment?

Control variables are factors that are kept the same to ensure that the results are valid.

How can one apply knowledge of apparatus and techniques in experiments?

One can suggest appropriate techniques, instruments, apparatus, or materials for a specified purpose and explain their relevance.

What should be considered when identifying hazards in practical contexts?

Identifying the main hazards and suggesting methods to reduce the risk of harm is crucial in practical contexts.

What is required when carrying out experiments?

Experiments should be conducted with proper manipulation of apparatus, accuracy of measurements, and health and safety considerations.

What is an appropriate sampling technique?

An appropriate sampling technique ensures that samples collected are representative of the population being studied.

What is the importance of recording measurements in practical contexts?

Accurate recording of measurements is essential for analyzing and interpreting experimental data.

How can one assess the quality of measurements taken in an experiment?

Assessing whether sufficient and precise measurements have been taken is important for evaluating the validity of the experiment.

What does it mean to evaluate methods in scientific research?

Evaluating methods involves determining whether they are valid and suggesting possible improvements or further investigations.

What types of data presentation methods should students be able to construct?

Students should be able to construct and interpret frequency tables, diagrams, bar charts, and histograms.

What is the process of translating data in scientific analysis?

Translating data involves converting data between graphical and numeric forms.

What mathematical skills are necessary for analyzing data?

Skills include using significant figures, finding the arithmetic mean and range, and performing order of magnitude calculations.

How can one determine the slope and intercept of a linear graph?

The slope and intercept can be determined through analysis of the plotted data points on the graph.

What is the physical significance of the area between a curve and the x-axis?

The area represents a measure of the quantity related to the graph, which can be measured by counting squares as appropriate.

What is always present when a measurement is made?

Some uncertainty about the result obtained.

How can uncertainty be measured in a set of measurements?

By using the range of the measurements about the mean.

What is the purpose of interpreting observations and data in scientific studies?

To identify patterns, make inferences, and draw conclusions.

What is required when presenting reasoned explanations in science?

Relating data to hypotheses.

What factors should be evaluated when assessing data quality?

Accuracy, precision, repeatability, reproducibility, and potential sources of random and systematic error.

What defines an accurate measurement?

It is close to the true value.

What characterizes precise measurements?

They cluster closely together.

What does it mean for measurements to be repeatable?

Similar results are obtained under the same conditions by the same investigator.

What does reproducibility in measurements refer to?

Similar results obtained by different investigators with different equipment.

What is random error in measurements?

Variations in results that occur in unpredictable ways.

How can random errors be reduced?

By making more measurements and reporting a mean value.

What is systematic error?

Measurement results that differ from the true value by a consistent amount each time.

What should be done with anomalous values in data?

They should be examined to identify the cause and possibly ignored if due to poor measurement.

What is essential for communicating scientific investigations?

Presenting coherent and logically structured responses using various forms of communication.

What is the purpose of using prefixes and powers of ten in science?

To express orders of magnitude (e.g., tera, giga, mega, kilo, centi, milli, micro, nano).

What skill is involved in unit conversion?

Interconverting units appropriately.

How should significant figures be handled in calculations?

Using an appropriate number of significant figures.

What are the two essential reactions for life on Earth?

Photosynthesis and respiration.

What is metabolism?

The sum of all the reactions happening in a cell or organism, involving the making or breaking down of molecules.

What is the basic unit of all forms of life?

Cells.

What is the process by which cells divide to produce two identical cells?

Mitosis.

What is the significance of stem cells in medicine?

They allow doctors to repair damaged organs by growing new tissue.

What are the main components of eukaryotic cells?

A cell membrane, cytoplasm, and genetic material enclosed in a nucleus.

How do prokaryotic cells differ from eukaryotic cells?

Prokaryotic cells are smaller, have no nucleus, and contain a single DNA loop along with plasmids.

What are the main sub-cellular structures in animal and plant cells?

Nucleus, cell membranes, mitochondria, chloroplasts (in plant cells), and plasmids (in bacterial cells).

How are the functions of sub-cellular structures related to their structure?

Students should be able to explain how the structure of each sub-cellular component is related to its specific function.

What is the role of the nucleus in eukaryotic cells?

It contains the genetic material and controls the cell's activities.

What is the function of mitochondria?

They are involved in energy production through respiration.

What is the function of chloroplasts?

They are involved in photosynthesis in plant cells.

What is the function of plasmids in bacterial cells?

They can carry additional genetic information, often related to antibiotic resistance.

What is the significance of the cell membrane?

It regulates what enters and exits the cell, maintaining homeostasis.

What is the relationship between cells and the environment?

All molecules are recycled between the living world and the environment to sustain life.

What are the main sub-cellular structures found in most animal cells?

Nucleus, cytoplasm, cell membrane, mitochondria, and ribosomes.

What additional structures do plant cells have compared to animal cells?

Chloroplasts and a permanent vacuole filled with cell sap.

What is the function of the cell wall in plant and algal cells?

It strengthens the cell and is made of cellulose.

What is the importance of cell differentiation in organisms?

It allows cells to develop into different types to perform specific functions.

Which types of cells are specialized in animals?

Sperm cells, nerve cells, and muscle cells.

Which types of cells are specialized in plants?

Root hair cells, xylem, and phloem cells.

What is the main purpose of microscopy in biology?

To observe and study cells and their sub-cellular structures.

How does an electron microscope differ from a light microscope?

An electron microscope has much higher magnification and resolving power.

What is the formula for calculating magnification?

Magnification = size of image / size of real object.

What is binary fission in bacteria?

A method of reproduction where bacteria divide into two identical cells.

How quickly can bacteria multiply under suitable conditions?

As often as once every 20 minutes.

What are the two common methods for culturing bacteria?

In a nutrient broth solution or as colonies on an agar gel plate.

What role do chloroplasts play in plant cells?

They are involved in photosynthesis, converting light energy into chemical energy.

What is a permanent vacuole and its function in plant cells?

A storage space filled with cell sap that helps maintain turgor pressure.

What is the significance of the nucleus in a cell?

It contains the genetic material and controls cell activities.

What is the function of mitochondria in cells?

They are the powerhouse of the cell, producing energy through respiration.

What is the role of ribosomes in cells?

They are responsible for protein synthesis.

What is the importance of using estimations in microscopy?

To judge the relative size or area of sub-cellular structures.

What is the significance of cell specialization in tissues and organs?

It allows for the efficient functioning of different systems within an organism.

What are the prefixes used in measurements related to microscopy?

Centi, milli, micro, and nano.

What is the main difference between plant and animal cell differentiation?

Most animal cells differentiate early, while many plant cells can differentiate throughout life.

What practical skills are developed through observing cells with a light microscope?

Drawing and labeling cells, including a magnification scale.

What is the relationship between cell structure and function?

The structure of a cell is adapted to its specific function within a tissue or organism.

Why are uncontaminated cultures of microorganisms necessary?

They are required for investigating the action of disinfectants and antibiotics.

What is the formula for calculating the cross-sectional area of colonies?

The formula is πr².

What technique should be used to prepare an uncontaminated culture?

Aseptic technique.

Why must Petri dishes and culture media be sterilised before use?

To prevent contamination.

How should inoculating loops be sterilised?

By passing them through a flame.

Why should the lid of the Petri dish be secured with adhesive tape and stored upside down?

To prevent contamination and moisture accumulation.

At what temperature should cultures generally be incubated in school laboratories?

25°C.

How can the number of bacteria in a population be calculated after a certain time?

Using the mean division time.

What is the role of chromosomes in a cell?

They carry a large number of genes and are normally found in pairs in body cells.

What are the stages of the cell cycle?

The cell cycle includes growth, DNA replication, and mitosis.

What happens during mitosis?

One set of chromosomes is pulled to each end of the cell, and the nucleus divides.

What is formed at the end of mitosis?

Two identical cells.

What is a stem cell?

An undifferentiated cell capable of giving rise to many more cells of the same type.

What is the function of stem cells in embryos?

They can differentiate into various types of cells.

What types of cells can stem cells from adult bone marrow form?

Many types of cells, including blood cells.

What is the role of meristem tissue in plants?

It can differentiate into any type of plant cell throughout the life of the plant.

What is therapeutic cloning?

It involves producing an embryo with the same genes as the patient for medical treatment.

Why might stem cells from embryos not be rejected by the patient's body?

Because they have the same genes as the patient.

What conditions may stem cell treatment help?

Conditions such as diabetes and paralysis.

What is the significance of understanding the cell cycle?

It is important for understanding growth and development in multicellular organisms.

What is the importance of aseptic technique in microbiology?

It prevents contamination during the preparation of cultures.

What are some potential risks associated with the use of stem cells?

Transfer of viral infection and ethical or religious objections.