Final review part 2: Ecology and genetics

ecology A branch of biology that deals with interactions between organisms and their environment

Organization in the environment Biosphere: portion of the earth where living things exist Biotic: grass, birds, squirrels, trees Abiotic: temperature, light, soil

Population: Group of species Community: living organisms in a given area Ecosystem: community and all its physical factors

Habitat: place where an organism lives Niche: role of an organism in an ecosystem

SYMBIOSIS A relationship where 2 species live closely together.

MUTUALISM relationship where both species benefit SYMBIOSIS

COMMENSALISM relationship where one organism benefits and the other is neither benefited nor harmed SYMBIOSIS

PARASITISM One organism benefits while the other is harmed. SYMBIOSIS

Food chain and food webs Autotrophs: make food Heterotrophs: ingest food Producers: make food (autotrophs) –Ex. Green plants

Sun is the main source of energy! Know how to interpret food webs! Food web: interconnected feeding relationship

Energy transfer in food webs Energy is transferred from the producers to the primary consumers, to the secondary consumers, ect.

Consumers Primary (first order): eat producers Secondary: eat primary consumers Tertiary/higher order

Consumers continued… Carnivores: eat meat (other animals) Herbivores: eat plants Omnivores: consume both

Scavengers: consume dead and rotting animals Decomposers: break down dead plants and animals, return nutrients to soil

Ecological Succession Primary succession: changes in an area that did not have previous life forms- begins on newly exposed surfaces Secondary succession: changes in areas where the previous community has been destroyed- begins on soil

Pioneer communities: first living organisms to colonize an area Climax communities: stable community

Biogeochemical cycles Nitrogen cycle: bacteria convert nitrogen gas into ammonia for plants Process is known as nitrogen fixation

Carbon/oxygen cycle: photosynthesis and respiration What process puts oxygen into the atmosphere? What processes put carbon dioxide into the atmosphere? What processes put very large quantities of carbon dioxide into the atmosphere?

WATER CYCLE

Water cycle Condensation –Water vapor builds up in clouds Precipitation –Rain, snow, etc Ground water –Water basin underground

Evaporation –Water passes from a liquid to a gas phase Transpiration -water vapor exits plants via leaves

What is a biome? Large geographic area that has a particular climate, native animals and plants, etc

climate The conditions such as temperature and amount of precipitation year-after-year determine the climate of a region.

Terrestrial Biomes Tropical Rain Forest Grassland (prairies) Tundra: very dry- permafrost, little precipitation! Savanna Desert: dry Coniferous Forest (or Taiga) Temperate deciduous forest- we live in one!

Aquatic Biomes Freshwater (lakes, ponds, streams, etc) Marine (oceans)

Natural Resources Non-renewable: –Fossil fuels (coal, oil, gas) perpetual: –Sun, wind, hydropower, geothermal renewable: –Trees, crops, fish

10% Law Only 10% of energy is passed from one trophic level to the next If 2000 kilocalories of energy is found in the primary consumers, how much energy is present in the tertiary consumers

Genetics

Before scientists knew about chromosomes and genes… Gregor Mendel –pea plants -traits are inherited through a passing factor from parents to offspring.

His Experiments… Crossed tall plants with short plants- all offspring were tall- the offspring is known as F1

Law of Dominance some traits are dominant and others are recessive

Law of segregation- cross out the two factors (alleles) for a trait separate during gamete formation

Law of independent assortment Traits are transmitted to offspring independently of each other

Incomplete Dominance one trait is not dominant- resulting in a blending phenotype. Ex. Mate a certain red and white plants create a pink offspring

Codominance Both dominant genes are expressed Ex. –Spotted dog –Blood type AB

Multiple alleles A trait that has more than two different alleles (RRYY)

Sex determination Genotype of a female: XX Genotype of a male: XY

Sex-linked traits Gene for the trait is located on the X chromosome Male only need one have one X so nothing to cover the trait that is why colorblindness is dominant in males

Blood types A, B, AB, O O is the recessive A and B are codominant Cross a male with O and female with blood type A--- what blood type will their children have?

What are the possible genotypes for each blood type? Blood type AB –AB Blood type O –ii Blood type B –Bi or BB Blood type A –Ai or AA

What is a test cross? Why is one used? A test cross determines genotype: Whether a particular characteristic of a plant or animal is homozygous dominant or heterozygous dominant

Vocabulary Genetics: study of how traits are passed on Alleles: different copies of forms of a gene controlling a certain trait Autosome: not a sex chromosome

Vocabulary (con’t) Homozygous: same alleles – tt or TT Heterozygous: when alleles for a certain gene are different -Tt

Genotype vs. phenotype Genotype: genetic makeup of an organism Phenotype: physical trait of an organism

Monohybrid cross vs. dihybrid cross Dihybrid –Two traits –Ex. Ttpp X ttPp (how many combinations of alleles do each parent have??) Monohybrid- one trait –Ex. Tt X tt

Be able to do punnett squares of all types like we did in class. Genotypic ratio: ratio of the different types of gene possibilities –Ex. 1 TT: 2Tt: 1tt Phenotypic ratio: ratio of the different appearances –Ex. 3 tall: 1 short

More problems… Cross a homozygous green plant with a yellow plant (green is dominant to yellow) Answer –GG X gg

More problems… Incomplete dominance: cross a red flower with a white flower Answer: –RR x WW –Offspring all have a genotype of RW and a phenotype pink

Last problem… Incomplete dominance: cross two pink flowers Answer: –RW x RW (draw on board)

Random

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