Biology - Finals
Terms
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- What are Mendel's 4 basic postulates?
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1. All traits are controlled by two units (alleles)
2. The units seperate in meiosis
3. Law of Dominance
4. Law of Independent Assortments - Homologous
- A pair of chromosomes with the same shape and contain the same genes.
- Heterozygous
- Having two different alleles for a given trait.
- Homozygous
- Having the same two alleles for a given trait.
- Chromosomes
- DNA all coiled up.
- Gene
- A segment of DNA that codes for a specific trait.
- Allele
- Variations of a gene.
- Dominant
- An allele that masks the presense of another allele of the same gene in a heterozygous combination.
- Recesive
- A trait whose expression is masked in a heterozygous combination.
- Gamete
- A haploid reproductive cell, either sperm or egg.
- Gonad
- The reproductive organ.
- Zygote
- The diploid product of the union of two haploids.
- Fertilization
- The union of the nucleus of an ovum and a sperm nucleus.
- Meiosis
- Two succesive cell divisions that produce gametes.
- Diploid
- A cell containing two sets of homologous genes (aka most of the cells in the body)
- Haploid
- A cell containing only one set of unpaired chromosomes.
- F1 Generation
- The 1st generation of hybrid offspring in a genetic cross.
- F2 Generation
- Offspring resulting from interbreeding the hybrid F1 generation.
- Centromere
- The specialized region of the chromosome that holds the replicated chromosome strands together, and that ataches to the spindle in mitosis.
- Nondisjunction
- The failure of a pair of homologous chromosomes or chromatid pairs to seperate during meiosis or mitosis.
- Carrier
- One who carries the recessive allele of a certain trait and does not express that trait but can still pass it on.
- Asexual Reproduction
- Reproduction without sex. ex: Amoebas
- Clone
- A linage of genetically identical individuals produced asexually.
- Mutations - What/Why/Results (good/bad/neutral)
-
A mutation is a change in the genetic sequence resulting in a new allele.
Causes - Mutagens: UV radiation, smoking, randomness
Harmful - cancer, disease
Neutral - most of the time
Good - helps us study how DNA works and how genes are regulated; variation -
Meiosis - results/where/importance/
oppurtunity for variation? - Meisis results in four gametes and occures in the gonads. Crossing over can occur before the last cell division.
- Karyotype
- A photograph of the choromosomes. Can indicate possible nondisjunction and gender.
- Barre Bodies/X inactivation
- In female mammals, one of the X chromosomes is turned off randomly in each cell. ex: calico cats
- Genetic Imprinting
- When the expression of a trait is influenced by which parent you inherited it from. ex: Huntington's
- Cytoplasmic Inheritance
- Since the mitochondria has its own DNA and only the mother passes down cell parts in the ovum, mitochondrial diseases can only be inherited from the mother, but she will give it to all her children.
- Epistasis
- When one gene controls whether another gene is expressed (it turns that gene on or off). ex: Labradors
- Heterotroph
- Cannot create their own food.
- Autotroph
- Can automatically make their own food.
- Decomposer
- Breaks down dead organisms and returns elements and energy back into the environment.
- Producer
- Produce their own food.
- Consumers
- Feed on other heterotrophs or autotrophs.
- Herbivors/Carnivors/Omnivores
- Plant/Meat/Both eaters (respectively)
- Name the six main biomes
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Tundra
Taiga
Deciduous
Grasslands
Desert
Rainforest - Primary Succesion
- Starts from something living.
- 3 types of Symbiosis + examples
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1. Mutualism: good<->good (lichens - protists + algae)
2. Parasitism good<->bad (ticks on dogs)
3. Commensalism good<->nutral (barnicles on whales) - Energy flow
- Law of 10% - in living transfers of energy only 10% is transfered
- Biogeochemical cycles
- Any cycle that goes between biotic and abiotic. Includes the water, carbon, and nitrogen cycle.
- Nitrogen Cycle
- Nitrogen absorbing bacteria takes Nitrogen from the air and into our bodies to be used by protein.
- Carbon Cycle
- Basically respiration and photosynthesis.
- Precipitation
- Rain, snow, hail, sleet, etc.
- Sublimination
- Solid to Gas
- Evapotransrespiration
- Evaporation from plants
- Condensation
- Gas to liquid
- Evaporation
- Liquid to Gas
- Water can be stored in...
- Ice and snow/groundwater/freshwater/ocean
- Infiltration
- Water absorbed into the ground.
- Aphotic Zone
- The zone in the ocean where light is insufficient for photosynthesis.
- Photic Zone
- The shallow top layer of the ocean where enough light penetrates for photosynthesis to occure.
- Greenhouse gas + effects
- CO2 creats a blanket around the earth, trapping in heat.
- Sources of carbon dioxide
- Fossil fuels and deforestation
- Causes/sources of Ozone depletion
- CFC's from refrigeration, air conditioning, cleaning solvents, airasol, ect.
- Acid Rain
- Pollution from factories gets in the air and chemically reacts, later falling as acid.
- Pathogens + examples
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1.Virus - flu, cold, HIV
2.Bacteria - strep, sal manila, e coli, pink eye
3.Fungus - athlete's foot
4.Protist - malaria
5.Animal - worm - Toxins
- Can be nonliving (heavy metals/chemicals) or living (botulism)
- Non-specific Defences
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1.Enzymes in saliva/tears/sweat
2.Skin
3.Membranes
4.Low pH of stomach
5.Fever
6.Inflamation
7.Phagocytes - Specific Defences
-
Lymphocytes
B Cells-made in bone marrow, make large amounts of antibodies (proteins) that bind to the antigen on invader and disable or mark it for destruction
T Cells-made in the thymus, emit chemicals that keep immune system on track and build immunity - Phagocytosis
-
Phagocytes - like pac man
Luecocytes - more specific - Definition of Evolution
- The change over time of populations of organisms from simple to complex.
- Natural Selection
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Directional-favors the weirdo
Stabalizing-remains at an average
Disruptive-favors extremes on both ends - Variation
- Caused by mutations and Darwin assumes that variation exists in a population for evolution to occur.
- Darwin
-
-Evolution happens in a process of natural selection
-variation must exist
-best adapted survive - Lamarck
- aquired characteristics
- Wallace
- came up with the same theory as Darwin
- Lyell
- -geologist; Uniformitarianism (the same forces at work in the past are at work today)
- Malthus
- limiting factors + biological potention = carrying capacity
- Hardy Weinberg model
-
p2 + 2pq + q2 = 1
p=dominant pq=hetero q=recesive
p+q=1
p=dominant allels q=recesive allels - Genetic Drift
- Changes due to chance in the gene pool of a small population
- Gene Pool
- All the genes in a population at any one time
- Bottleneck Effect
- When the # of organisms is drastically reduced for a few generations, which leaves the population inbred.
- Founder's Effect
- Colonization by a small population that differs in genetic makeup from its source population.
- Homologous Structures
- Sharing a common ancestor even if the function differs (ex: human hand and dolphin fin)
- Analogous Structures
- Similarity in form or function but not the result of a common ancestor, indicates evidence of similar biological preasures (ex:incect wing and bird wing)
- Co-evolution
- The evolution of two species interacting with each other and reciprocally influencing each other's adaptations (ex: pollenators+plants; ants+acacia tree)
- Definition of Species
- Must be able to produce viable offspring.
- First fossil evidence of life __ years ago.
- 3.5 billion
- Earth is __ years old.
- 4.6 billion
- Carbon Dating
-
-accurate up to 60 thousand years
-half life of about 5730 years - Potassium/Argon Dating
- -used for more geological puroposes and rocks >100000 years old
- Why was oxygen missing from the original atmosphere?
- No photosynthetic organisms existed to create it.
- Where did oxygen come from?
- Photosynthetic life
- Punctuated Equilibrium
- Periods of alternating gradual and rapid evolution.
- Gradualism
- Constant, steady evolution over time.
- Taxonomy
- The classification of organisms in ways that reflect relationships and help distinguish types of organisms
- Binomial Nomenclature
- a two word naming system for each species, together these two words form the scientific name.
- Heirarchial Classifications
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Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species - Six/Five Kingdoms
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Eukaryotic
Protist
Plant
Fungus
Animal
Prokaryotic
Archea
Bacteria - Genus vs. Species
- Species is more specific than Genus, both are italized and in latin, the Genus comes before the Species and is capitalized
- Darwin's contribution to taxonomy
- Developed a new system of relationships based on morphological observations
- Comparitive DNA sequencing
- Indicated how closely two organisms are related by recording how similar their DNA sequences are. Now used to group animals in taxonomy.
- Three Domains
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Archea-no nucleus; live in extreme environments
Bacteria-no nucleus;live everywhere; decomposer; disease
Eukaryia-nuclues+cell parts - Four kingdoms of Eukaryia
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Protist-single celled
Plant-Autotrophical
Fungus-disease; decompose; food
Animal-invertabrates&invertabrates - Prokaryotic vs. Eukaryotic
- A prokaryotic cell has no nuclues and lacks certain cell parts
- Chloroplast
- Photosynthesis; seperate DNA; located in plant cells only
- Mitochondria
- Respiration; seperate DNA; located in both plant and animal cells
- Carbohydrates
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-C,O,H (2:1 ratio)
-sub-unit=saccharide - Lipids
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-C,O,H (not a fixed ratio)
-sub-unit=fatty acids+glycerol - Protein
-
-C,H,O,N, and sometimes S
-sub-unit=amino acids
-function: enzymes, hemoglobin, immune system, hair, muscles, ect. - Nucleic Acid
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-sub-unit=phosphate+sugar+"base"
-function: DNA and RNA - Four DNA nucleotide/four RNA nucleotides
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Thymine (Uracin in RNA)
Adenine
Guanine
Cytocine - Cell Membranes
- Selectively Permeable, depends on polarity, size, and electric charge (charged/large molecules need special transport proteins)
- Organic vs. Inorganic molecules
- Organic molecules must contain carbon
- Six main elements found in living organisms
- Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur
- Diffusion
- refers to the movement of molecules from and area of higher concentration to an area of lower concentrations
- Osmosis
- the movement of water down its concentration gradient
- Turgor
- the outward presure of a cell against its cell wall
- What happens to an animal/plant cell in water?
- An animal cell will burst and a plant cell will exprerience increased turgor
- Endocytosis
- Pulling something in through active transport
- Exocytosis
- Pushing something out through acive transport
- Mitosis
- Results in two identical daughter cells each with the same number of chromosomes as the parent cell.
- Photosynthesis reaction
- 3CO2 + 3H2O -> C3H6O3 +3O2
- Ribosomes
- Small bodies composed of RNA and protein; catalyse the synthesis of cell proteins