Mitosis and transport in cell Flashcards
What are chromosomes?
Coiled strands of DNA molecules.
What is a gene?
A section of DNA that codes for a protein.
What is DNA?
A genetic material found in the nucleus that codes for proteins.
How many chromosome pairs do you find in a human body cell?
23 pairs
What is mitosis and what is it used for in animals and plants?
Growth, repair and asexual reproduction.
Which type of human stem cell can differentiate into any human cell?
Embryo stem cells.
What is therapeutic cloning?
Where patients are given stem cells containing the same genes as theirs.
Define ‘diffusion’?
The movement of the particles from an area of a high concentration to an area of low concentration.
State three places where diffusion occurs in the body.
Small intestines, lungs, kidneys
What three factors affect rate of diffusion?
Concentration gradient, temperature, surface area.
State how the following are adapted for diffusion:
a. The small intestines.
b. The lungs.
c. Gills in fish.
d. Roots.
e. Leaves.
a. Have villi to increase surface area, good blood supply, thin membranes.
b. Have alveoli to increase surface area, good blood supply, thin membranes, they are ventilated.
c. Have gill filaments and lamella to increase surface area, good blood supply, thin membranes.
d. Have root hair cells to increase surface area.
e. Large surface area, thin and stomata.
Define osmosis?
Osmosis is the movement of water particles from a high concentrated solution to a low concentrated solution through a partially permeable membrane.
What is a partially permeable membrane?
A membrane that lets some but not all substances through.
Define active transport.
Active transport moves substances from an area pf low concentrated solution to a higher concentrated solution (against a concentration gradient) using energy from respiration.
Why does active transport need to occur in root hair cells?
Because the minerals are at a higher concentration in the roots than in the soil.
