Biology paper 1 b1-5 Flashcards
Define a cell
The basic unit of living things
Name five organelles found in animal and plant cells
Nucleus, cytoplasm, cell membrane, ribosome, mitochondria.
Name the three organelles only found in plant cells
Cell wall, chloroplasts, vacuole.
Define a eukaryotic cell
A cell with a true nucleus.
Define a prokaryotic cell
A cell without a true nucleus.
Give the function of the nucleus
Controls all activities of the cell.
Give the function of the mitochondria
Does aerobic respiration which produces energy.
Give the function of the ribosomes
Protein synthesis.
Give the function of the cytoplasm
Chemical reactions.
Give the function of the cell membrane
Controls the movement of substances in and out of the cell.
Give the function of the cell wall
Provides structure and support.
Name the chemical that makes the cell wall
Cellulose.
Give the function of the chloroplasts
Photosynthesis.
Define a specialised cell
A cell adapted to perform a specific function.
Name 4 different types of specialised animal cells
Nerve cells, muscle cells, sperm cells, red blood cells.
Name 3 different types of specialised plant cells
Xylem cells, phloem cells, root hair cells, photosynthetic cells.
Give the equation to calculate magnification
Magnification = Size of Image / Size of real object
Calculate how many micrometres are there in a millimetre
1000.
Define diffusion
Movement of particles from high to low concentration.
Name 3 factors that affect the rate of diffusion
Surface area, concentration gradient, temperature.
Define osmosis
Diffusion of water from dilute to concentrated solution, across a partially permeable membrane.
Define active transport
Movement of substances from low to high concentration. Requires energy.
Describe how the alveoli in the lungs are adapted for gas exchange
Large surface area, good blood supply, thin walls.
Describe how the microvilli in the small intestine are adapted to absorb glucose
Large surface area, good blood supply, thin walls, lots of mitochondria.
Name the three stages of the cell cycle
Replication, Mitosis, division.
Describe what happens during replication.
Cell grows and DNA is copied.
Describe what happens during mitosis.
Contents of the cell are rearranged - one set of chromosomes are pulled to each end of the cell. Nucleus divides.
Describe what happens during division.
Cytoplasm and cell membrane divides. Two identical daughter cells are produced.
Define a stem cell.
Unspecialised cell.
Define differentiation
Process by which cells become specialised.
Give the three types of stem cells.
Embryonic, adult and plant stem cells.
State the advantage of using embryonic cells
They can differentiate into almost all types of cells.
Give the location of adult stem cells.
Bone marrow.
Give the location of plant stem cells.
Meristem tissue in shoots and root tips.
Give the advantages of using stem cells.
Cure diseases, increases our knowledge, can be used to increase crop production.
Give the disadvantages of using stem cells.
Expensive, research is slow, health effects unknown, adult stem cells can carry viruses, religious/ethical objections.
Define cell
Basic unit of living things.
Define tissue
Groups of similar cells performing the same function.
Define organ
Group of tissues performing the same function.
Define organ system
Groups of organs performing the same function.
List the three types of tissue
Muscular, glandular and epithelial.
Describe the role of bile
Neutralises stomach acid and breaks fats down into droplets.
Name the organ where bile is produced
Liver.
Name the organs involved in digestion
Mouth, oesophagus, stomach, liver, small intestine, large intestine, anus.
Give the function of the small intestine
Reabsorbs glucose from digested food.