lab practical 3 outline

# lab practical 3 outline - Quantitative Changes in...

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Quantitative Changes in Population - Linear Growth - Simplest of the three patterns - Ex: corn seed - Consists of embryo and food supply - Region of active cell division: apical meristem - fixed number of cells reproduce in each generation - n = ct + N 0 - c = rate of increase (change in population size per unit time) - = dN/dt = slope - t = time (in generations) - N 0 = initial population size - growth rate is constant - growth rate is independent of population size - Unrestricted Exponential Growth - Fixed proportion of cells reproduce - 4 8 16 … - N = N 0 e rt - e = Euler’s number - r = intrinsic rate of increase - t = time (in generations) - N 0 = initial population size - dN/dt = slope = rN - rate of increase and slope aren’t constant, but are constantly changing

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- growth rate is proportional to the population size - Logistic Growth - A type of exponential growth that occurs in environments where various factors restrict growth. - Lag phase: birth > deaths, but growth is slow because of small population - Log phase: birth > death, but many of the organisms are reproducing and accelerating growth - Stationary phase: birth = death - because environment can’t support more people - carrying capacity (K): number of individuals in a population that an environment can support indefinitely. - factors influencing carrying capacity: resource and space limitations, competition, predation, … - = ( dNdt rN K - ) N K - Influenced by difference between carrying capacity and population size - Allele Frequencies in Populations: Hardy-Weinberg Law - Evolution: change in the allele or genotype frequencies of a population over time - Population: localized group of interbreeding species members - Gene pool: entire collection of alleles in a population - Genotype: genetic composition of an individual - Allele: each gene variant is a particular allele - Genotype frequency is the fraction of a population with a particular genotype - Allele frequency is the fraction of a particular allele in the population’s gene pool - 5 Hardy-Weinberg Assumptions: - Population is so large, chance alone would not significantly alter allele frequencies.
- Mutation must not occur - No immigration/emigration - Random mating - Reproductive success must be random (natural selection) - Diversity of Life on Earth - Green Plants - Eukaryotic - Autotrophs - Chlorophylls a and b - Cell walls made of cellulose - Unique life cycle consisting of two alternating phases - Make gametes (egg and sperm) to reproduce - Sperm and egg each donate a set of chromosomes to the zygote which makes it diploid - Diploid zygote grows by mitosis, which ensures that the descendants of a cell have the same number of chromosomes as the original. -

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lab practical 3 outline - Quantitative Changes in...

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