Biology EOCT Review Milton High School. Cell Organelles Nucleus – holds DNA Cell membrane – what...
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Transcript of Biology EOCT Review Milton High School. Cell Organelles Nucleus – holds DNA Cell membrane – what...
Biology EOCT Review
Milton High School
Cell Organelles
• Nucleus – holds DNA• Cell membrane – what comes in and goes out• Mitochondria – powerhouse of the cell• Ribosomes – protein synthesis• Lysosomes – digestion• Cell wall – structural support (ex. plants)• Vacuoles – storage• Chloroplasts – in plants for photosynthesis
Animal cell vs. Plant cell
Differences in Cells
Prokaryote• Lacks nucleus• No membrane-bound
organelles• Has a cell wall• Has a cell membrane• Bacteria
Eukaryote• Has a nucleus• Has membrane-bound
organelles• Found in plants, animals,
fungi, and protists
Viruses• Relies on a host cell to reproduce• Has DNA or RNA
Osmosis• How water diffuses into a cell• Diffusion is process which molecules of a substance move
from an area of high concentration to an area of low concentration
Macromolecules
• Carbohydrates – glucose and sucrose– Provide quick energy– Polysaccharides are largest
• Lipids – fats, oils, waxes– Insoluble in water– Storage of energy
• Proteins – basic building materials– Also contain nitrogen– Made of amino acids (there are 20)
Mitosis vs. Meiosis
Mitosis• Generates TWO identical
cells• Maintains chromosome
number (Diploid number)• Occurs in body cells
(somatic cells)
Meiosis• FOUR cells are formed • Each with half of the
number of chromosomes (Haploid number)
• Forms sex cells (gametes)• Requires two cell divisions
Genetics
• Genes are located on chromosomes• Homozygous – both alleles are the same (TT)• Heterozygous – alleles are different (Tt)• Dominant alleles express themselves• Recessive alleles are hidden• Phenotype – physical appearance• Genotype – set of alleles individual receives
Some important ecology terms
• Community – multiple populations• Abiotic – non-living items in environment• Trophic levels – different levels in food chain– Each level gets energy from level below it– Less energy available as move up to next level
• Habitat – where an organism lives• Niche – what an organism does in habitat
Less energy available to next level – some
energy used for respiration, growth,
reproduction.
Parasitism – one species benefits and the other species can be
harmed (need a host)
Tick is an example
Commensalism – one species benefits and the other species is
neither harmed nor helpedThe remora and the shark
is an example – the remora is a fish which has
“suction” disks which allow it to attach to shark
without hurting the shark
Mutualism – both species benefit
A lichen is formed by a relationship between a fungus and a green algae. The fungus
anchors the lichen and protects the algae from direct sunlight
and extreme temperature fluctuations. The green algae
performs photosynthesis, providing food for itself and the
fungus.
Natural selection - results in the evolution of organisms best adapted to the
environment
Nectar feeding
Seed-eating
Acid rain – produced when nitrogen oxide (from car exhaust) or sulfur dioxide (from burning fossil fuels) mixes with rain
Enhanced greenhouse effect – more heat trapped –caused by excess carbon dioxide and other greenhouse gases
released into the atmosphere