Biology Paper One

• What is a communicable disease? A disease that can be transferred between people - easily spread
• What are some examples of communicable diseases? HIV/AIDS, Ebola, Chicken pox, Measles, Mumps, Rubella.
• What is a microbe? A living organism that is invisible to the naked eye and can only be seen under a microscope.
• What is a pathogen? A microbe that causes diseases.
• How do viruses damage our cells? They use host cells to reproduce rapidly inside your body and eventually they fill the cell and it bursts - releasing all the new viruses (cell damage makes us feel ill)
• How do bacteria damage our bodies? Once bacteria are in our body, they release toxins that damage our cells and tissues
• Why do viruses need a host cell to reproduce in? Viruses need a host cell to reproduce as they aren't living organisms.
• What are protists? Protists are eukaryotes and most of them are single-celled, some are parasites which live either in or on organisms and cause damage.
• What are eukaryotic cells? - Eukaryotic cells are complex and include all animal and plant cells. - Their DNA is enclosed in a nucleus
• What are prokaryotic cells? - Prokaryotic cells are smalle and simpler - like bacterial cells. - Their DNA floats free in the cytoplasm.
• What are organelles? An organelle is a subcellular structure that has one or more specific jobs to perform in the cell.
• What are examples of organelles? Mitochondria Ribosomes Choloroplasts...
• What is a membrane-bound organelle? An organelle surrounded by a membrane.
• Only eukaryotic cells have membrane-bound organelles.
• Only prokaryotic cells have plasmids.
• What are examples of eukaryotic cells? Plant and animal cells
• What are plasmids? Small rings of DNA
• What shape is DNA in prokaryotae? DNA is in a single loop in prokaryotae
• Which type of cell is the oldest and simplest? (Eukaryotae vs Prokaryotae) Prokaryotic cells are the oldest and simplest
• Which type of cell is bigger and more complex? (Eukaryotae vs Prokaryotae) Eukaryotic cells are bigger and more complex
• What is a benefit of having DNA housed in a nucleus? The DNA is protected
• What is a benefit of having plasmids? Plasmids allow the cell to transfer its DNA to other cells which can give them extra characteristics.
• Why do bacteria have free-floating DNA? So that they can reproduce quicker
• What is a flagellum? A tail-like structure that helps the cell move faster
• What is the cell wall made of? Cellulose - supports and strengthens the cell
• What is the function of the nucleus? The nucleus contains the genetic material (DNA) and controls the cell's activities.
• What is the function of the cytoplasm? The cytoplasm is a jelly-like substance where chemical reactions take place in the cell. It contains enzymes that control these chemical reactions.
• What is the function of the cell membrane? The cell membrane controls what goes in and out of the cell.
• What is the function of the mitochondria? The mitochondria are where aerobic respiration takes place. They're the powerhouse of the cell.
• What is the function of the ribosomes? The ribosomes are where protein is synthesised (made).
• What is the function of chloroplasts? Chloroplasts contain the chlorophyll needed for photosynthesis.
• What is the function of the vacuole? The vacuole stores extra water and sap to help keep the cell turgid and give it extra support.
• What is the symbol for metres? m
• How big is 1 centimetre in metres? 1x10-2m
• How big is 1 millimetre in metres? 1x10-3m
• What is the symbol for millimetres? mm
• How big is 1 micrometre in metres? 1x10-6m
• What is the symbol for micrometres? μm
• How big is 1 nanometre in metres? 1x10-9m
• How do light microscopes form images? Light microscopes use light and lenses to form images of a specimen and magnify it.