Exam Flashcards
(27 cards)
Multicellular VS unicellular
Mulicellular- cells specialized for particular functions
Unicellular- consist of one cell
Two components of cell theory
1) cells are the units of structure and function in all organisms
2) all cells come from pre existing cells
Who is Leeuwenhoek?
Dutch- designed microscope to study bacteria
Hooke
Cork layer and saw compartments (cells)
Light microscope
Light passes through small or thinly sliced organism
Phase contrast microscope
Differences in light and dark making cell structure more visible
Electron microscope
Uses electron beams
What is evolution?
A change through time in species
Example of evolution
Peppered moths: industry caused mutation of black moths to adapt to dark environment
What are species?
Organisms closely related that they can mate and reproduce.
3 Distinctness in species:
1) behavioural
2) geographical
3) physical differences
What is reproductive isolation ?
The inability of groups to breed successfully. Ex) and elephant an crab cannot reproduce offspring
What is a variation?
Differences among individuals o. The same species.
Artificial selection
Selective breeding of domestic plants and animals to encourage desirable traits
Natural selection
Mechanism of evolution- adaptation to environment are more likely to survive
Adaptations
Characteristics that enable members of a species to survive and reproduce.
Lamarks theory and example
Acquired characteristics are passed on to offspring
Ex) giraffes stretch their necks to reach tall leaves, the effort genetically changes them and the longer neck is passed on to offspring.
Darwins theory and example
Means of natural selection
Ex) he suggested any Populations of giraffes have variations. Those with longer necks can reach more leaves and is better fed. The stronger survive
Give an example of how predation can be more beneficial to the prey than some other limiting factor
Wolf is predator and bunny is prey. Wolf hunts the weak ones and therefore the ones who survive will eat more and reproduce to create more fast and stronger bunnies
2 density independent factors
Lack of oxygen and temperature
What is nitrogen fixation?
Changing of nitrogen gas into usable form of bacteria
What is denitrification?
Process which nitrogen is released from soil by denitrifying bacteria
Compare and contrast latitudinal and altitudinal succession.
Latitudinal- succession of a community type from equator to poles
Altitudinal- succession from low to high altitudes
What is biosphere?
World of life
