Biology Exam - SBI3U1

• Angiosperms can be classified into monocots and dicots.
• Vascular bundles are scattered in monocots and arranged in a ring in dicots.
• Monocot leaves have parallel veins, while dicot leaves have net-like veins.
• Xylem have open tapered ends and are dead when mature. The function is to deliver water and dissolved materials throughout the plant and to provide strength for stems and roots.
• Genetic drift is most likely to occur in small populations.
• Stabilizing selection acts to reduce the more extreme forms of a trait.

  Eg. average size bills on hummingbirds are selected if the flowers are average sized
• The form of isolation that prevents reproduction due to individuals breeding or reproducing at different times is temporal isolation.
• The Bottleneck Effect: changes in gene distribution that result from a rapid decrease in population size. A catastrophe can quickly reduce population size.
• Founder Effect: New populations formed by only a few individuals, founders carry some but not all of the alleles from the original gene pool.
• Directional selection favours an increase or decrease in one trait.

  Eg. evolution of the peppered moth
• Disruption selection favours two or more forms or variations of a different trait.

  Eg. light and dark coloured oysters camouflage better than medium coloured ones
• Sexual selection is reproductive success that results from gaining mates where certain traits are favoured and passed.

  Eg. rams horns, contest of strength
• Speciation is any series of events that results in the reproductive isolation of two populations, it may also lead to the formation of a new species.
• The main taxonomic ranks are: Kingdom, Phylum, Class, Order, Family, Genus, Species
• Scientifically, organisms are named with the taxonomic ranks of Genus + Species
• The lysogenic cycle involves the viral DNA incorporating inside the cell's DNA, the virus integrates itself into the host
• The lytic cycle involves the virus taking over the cell and replicating until there are too many and the cell bursts open
• Humans are affecting biodiversity by:

  1. exploitation
  2. destroying habitats
  3. overfishing
  4. bringing invasive species
  5. influencing climate
• Prokaryotes: unicellular, lack nucleus, lack organelles
• Eukaryotes: often multicellular, have nucleus, found in humans
• Viruses do not appear in any kingdom because they can't grow or reproduce on their own and do not carry out any metabolic functions. They are neither living or dead.
• Germination is the process by which growth resumes in a seed after it has been dormant
• Lichen are a pioneer species because they are able to grow on rocks with no soil
• Stems may be herbaceous (soft, green) or woody (stiff with wood tissue)
• Meristematic tissues are cells that divide by mitosis and are responsible for plant growth
• Ground tissues are all internal cells except ones that transport substances. They play roles in storage, support, and photosynthesis.
• An example of a homologous structure, body parts that have the same evolutionary origin but different functions, is the legs of a horse and fins of a whale.
• Analogous features are body structures that have a similar function but different structures, like a bat wing and butterfly wing.
• Natural selection means that populations change over many generations
• Fossil evidence supports ideas of change with variation among multiple fossil pieces
• Natural selection predicts that environmental conditions select for particular traits
• Mutations, Gene Flow, Non-random Mating, and Genetic Drift are all mechanisms of evolution.
• Gene Flow describes the net movement of alleles from one population to another. With this come new alleles into a gene pool and genetic diversity can increase.
• The lung picks up oxygen, goes through the pulmonary vein into the heart, through the left atrium and ventricle, and is pumped to the body. The aorta is the major artery out of the heart. Veins take the deoxygenated blood back to the heart through the vena cava's, through the right atrium and ventricle, which goes through the pulmonary artery back to the lungs.
• Lungs -> Pulmonary Veins -> Left Atrium -> Left Ventricle -> Aorta -> Vena Cava -> Right Atrium -> Right Ventricle -> Pulmonary Artery