BIO EXAM

Cell theory 3 points -The cell is the smallest living orgnasim unit -All organsims are compsed of cells -All cells come from pre-existing cells

Identify the structure of prokaryotic cells and give an example Have a cell wall- always single-celled (unicelluar). Bacteria are the main type of prokaryotic cells,

Identify the structure of eukaryotic cells and give an example Cell wall- chloroplast-large vacuum,

Outline the key differences between prokaryotic (bacterial), animal and plant cells Plant cells have a cell wall and animal cells don't.

Mitochondria Has an outer membrane, and an inner folded membrane (cristae). Organelle where most energy, in the form of ATP, is made for use by the cell. Contains its own DNA.

Rough endoplasmic reticulum Rough ER due to ribsomes attached to the surface (RER). Folds proteins into specific shapes.

Chloroplasts Double membrane surrounding inner stacks of thylakoid membrane called grana. Uses light energy, water and carbon dioxide to produce glucose (photosynthesis)

Photosynthesis Process Process where plants use chlorophyll and light energy to turn into carbon dioxide (air) and water (soil) into chemical energy in form of glucose.

Photosynthesis Organelle involved Occurs in the thylakoid membrane and in the storma of chloroplasts.

Aerobic cellular respiration Occurs when there isn't oxygen available. Reaction occurs in thy cystol only.

Describe and Label plasma structure

Fluid Mosaic Model Plasma membrane ,made up of a phospholid bilyaer. Hydrophilic head (water-loving) Hydrophobic tail (water hating)

Simple diffusion Small, non-polar molecules ( o2 co2) diffuse directely through phospholid.

Facilitated diffusion Some substances cannot dissolve across the membrane due to size or charge. These substances move across via transport proteins.

Osomios Movement of water molecules

Bulk Transport- Endocytisis Transport of large particles into a cell.

Bulk Transport- Exocytosis Transport of large substances OUT of cell.

Microevoultion (population gentics)

Macroevulation Speciation

Outline the process of natural selection

Fitness A measure of how well an organism survives and reproduces in it’s environment.

Species A group of interbreeding organisms that produce viable and fertile offspring in nature.

Outline the process of allopatric speciation Initially a population (or populations) of the same species become seperated by a geographical barrier preventing gene flow

The isolated populations are exposed to different selective pressure favouring different phenotypes, and allowing gentic differences to accumlate

Over time, sufficent geneitic differences accumalte in the 2 populations so they can no longer interbreed to produce viable, fertile offspring. Hence, 2 new species

geographical barrier A physical barrier that isolates populations from each other, preventing gene flow and allowinf genetic differences to accumulate.

Fossil Are the preserved remains of long dead organisms.

Abouslote dating= works out a estimate of the abousoulte (age in years of a fossil) Relative dating=Describes the age of a fossil compared to other fossils.

Perminarlised fossils Fossils formed when organic matter is gradually replaced by hard minerals.

Impression fossils Fossil formed when an organism is encased in material but decomposes or is removed and the gap is filled with another substance.

Mummifed Fossils Fossil formed when the body is under conditions that slow down or stop the decaying process.

Transitional fossil Fossils that show an intermediate stage of evolution.