Life Flashcards
What are the 8 characteristics of living organisms?
Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition, Control (MRSGREN)
What sub-cellular structures are found in animal cells and what are their functions?
Nucleus (controls activities), cell membrane (controls entry/exit of substances), mitochondria (site of respiration), and ribosomes (site of protein synthesis)
What sub-cellular structures are found in plant cells and what are their functions?
Nucleus, cell membrane, cell wall (supports the cell), chloroplasts (photosynthesis), mitochondria, vacuole (contains cell sap), and ribosomes.
What sub-cellular structures are found in bacterial cells and what are their functions?
Chromosomal DNA (controls cell activity), plasmid DNA (extra genes), cell membrane, ribosomes, and flagella (movement).
How are sperm cells adapted to their function?
They have an acrosome (enzymes to penetrate egg), a haploid nucleus (half the DNA), mitochondria (energy for movement), and a tail (swimming).
How are egg cells adapted to their function?
They contain nutrients in the cytoplasm, a haploid nucleus, and changes occur in the cell membrane after fertilisation to prevent other sperm entering
How are ciliated epithelial cells adapted to their function?
They have cilia (tiny hairs) that move mucus or fluids over the cell surface.
What are the levels of organisation in organisms?
Organelles → Cells → Tissues → Organs → Organ systems.
How has microscope technology improved our understanding of cells?
Developments like the electron microscope allow us to see cell structures with greater clarity and detail than before.
How do you calculate magnification in microscopy?
Magnification = Image size ÷ Real size.
What are the standard units used for measuring cells and their conversions?
Milli (10⁻³), Micro (10⁻⁶), Nano (10⁻⁹), Pico (10⁻¹²)
How do substances move into and out of cells?
By diffusion (passive), osmosis (water only), and active transport (requires energy).
What factors affect the rate of movement of substances into and out of cells?
Surface area to volume ratio, temperature, and concentration gradients.
What is a simple experiment to demonstrate diffusion?
Use agar jelly cubes containing a pH indicator and place them in acid to observe diffusion by colour change.
