Biology paper 1 Flashcards
State each stage of mitosis.
1) (parent)Cell replicates the number of organelles and chromosomes so the daughter cells have an equal amount.
2) the organelles and chromosomes line up along the centre
3) the cell divides
4) two new cells are made
Name two places where stem cells can be found.Another one for where they are found in plants.
bone marrow-A stem cell
Human embryos-E stem cells
Plants-meristems
Disadvantages of stem cells
Ethical and religious debates
Infectious risks.
Name some uses of stem cells.
Used to treat conditions like diabetes.Can produce clones of plants quickly.
What is an enzyme.
biological catalyst
List properties of enzymes.
Large proteins.
A Space within the enzyme is known as the active site.
Have an optimum temperature and PH where they work best.
What happens to enzymes at high temperatures.
The bonds holding it together break which changes the shape.(It becomes denatured)
What is blood made of.Also name its components (blood not what its made of)
Plasma. RBC, WBC and platelets
What are chromosomes
Genetic material that are coiled up lengths of DNA molecules
What do chromosomes carry that control characteristics like hair and eye colour?
genes
How many chromosomes does a human cell have.
23 pairs of chromosomes
Name the four chambers in a heart.
Left and right atria and the left and right ventricles
what prevents the back flow of blood?
valves
What chamber does the blood enter
Atria
Define diffusion
Net movement from an area of high conc. to an area of low conc. until they are evenly spread out.
Name an example of diffusion
-o2 and co2 in lungs, gills and plant leaves.
Name two treatments for CHD
stents to keep arteries open.
statins to reduce the blood cholesterol so that the build up of fatty materials slows down.
what causes cancer.
Uncontrolled cell division.
How are malignant tumours formed?
pieces of benign tumours break off and are transported by the blood where they can form in other places
what do cells do in order to become specialised?
they change shape and different sub-cellular structures so that they can carry out a specific function.
What are antibiotics
Medicine that doctors prescribe for certain diseases.
what is MRSA
Strain of bacteria that is resistant to bacteria development.
what are ribsome?
small structures in the cytoplasm where protein synthesis occurs
what is a vacuole?
fluid filled cavity in a cell that used for storage and transport
what does cellulose do in plants
makes up the cell wall
what is dna?
nucleic acid molecules that contain genetic information and make up chromosomes
what is a gene and what does it do?
part of a chromosome, made up of dna and codes for protein
what is therapeutic cloning
clones that are produced to treat diseases and are not allowed to develop into new offspring
describe the structure and it’s function for arteries
artery walls are thick strong and elastic because the heart pumps out the blood at high pressure.Thick compared to lumen and elastic fibres so they can stretch.
describe the structure and it’s function for capillaries
permeable walls so substances like oxygen and food diffuse in and out they take away co2.thin walls to decrease distance that diffusion has to occur over.
describe the structure and it’s function for veins
bigger lumen than arteries because of the lower pressure and valves so blood flows in right direction.
what is a vector?
organism that carries pathogen but does not suffer from the disease
what is digitalis?
drug extracted from foxglove, used for heart problems
what is aspirin
painkilling drug first extracted from the bark of willow tress
what is penicillin
an antibiotic extracted from a fungus
process of anaerobic respiration in animals
glucose to lactic acid
process of anaerobic respiration in plants and yeast
glucose to ethanol and carbon dioxide
what is lactic acid?
compound produced when cells respire without oxygen
what is oxygen debt
oxygen deficiency cause by anaerobic respiration
Usage of glucose in plants, other than respiration or storage
used to produce fat or oil for storage
used to produce cellulose, which strengthens the cell wall
used to produce amino acids for protein synthesis.
2 factors that are not water and temperature that affect photosynthesis
light intensity
carbon dioxide concentration.
why do plants need magnesium ions?
It is needed to synthesis chlorophyll
