Lab bio

• What key characters evolved in the lineage of angiosperms?


  Flowers
• what key character evolved on the lineage to gymnosperms and angiosperms?

  Seeds
• What key characteristics evolved in lineages to lycophytes, ferns, gymnosperms, and angiosperms?

  Vascular tissue
• What three traits are unique to Embryophytes?

  Alternation of generations, walled spores, and apical meristems
• Eudicots Have taproots Organized vascular tissue in rings Where secondary development comes from,only eudicots have this.
• Monocots Have Fibrous roots Random assortment of xylem and phloem
• Angiosperms Known for having flowers and fruits The seed is considered “Covered”—because it is within the fruit Every fruit comes from a flower, and every flower has a fruito Parts of the flower Sepals: leaf  Petals: colored portion of the flower Stamens: Anther and Filament  Carpels: stigma, stye, and ovary
• Gymnosperms Known for having seedso Specifically – “Naked” seeds. Naked because the seed is exposed Have cones Do NOT have flowers or fruits
• 4 group of plants:  Bryophytes  Lack vascular tissue  Are Gametophyte dominate  Mosses and liverworts Seedless vascular plants  Have vascular tissue

  o Xylem – tissue takes water up from roots Phloem – tissue take sugars down from the leaves

   Mostly ferns  Lack seeds
• Gametophyte – 1n generationo Makes gametes via mitosiso The dominant generation in the Bryophyteso Male = antheridiumo Female = archegonium Walled spores produced in the sporangia Apical Meristems tissue
• Plants

  o 3 synapomorphies that all plants share

   Alternations of generations  Sporophyte – 2n generation

  o Makes spores via meiosis

  o The dominant generation in the Seedless vascular plants,gymnosperms, and angiosperms
• The sporophyte produces spores through meiosis.
• Phylogenetic tree:o Synapomorphy = shared derived trait. A trait thatdefines a clade Homologous traits – similar doe to ancestry Analogous traits – similar, but not do toancestry
• 8 levels of classification: (D-K-P-C-O-F-G-S)o Domain o Kingdom o Phylum o Class o Order o Family o Genus o species
• Evolutiono Evolution occurs in populations (not individuals).o Populations = a group of organisms of the same species.o Microevolution = a change in allele and genotype frequencies over time Gene Pool = the genetic makeup of a population (all of the genotypes)
• Hardy-Weinberg Equilibrium (HWE) is a mathematical measure to determine if a population is evolving
• In HWE, a population is not evolving; the genotype frequencies are stable
• If a population is not in HWE, it is evolving
• HWE requires 5 assumptions:

  • No Selection: no individuals are more successful at surviving and reproducing
  • No Mutations: no new alleles are formed or lost due to mutation events
  • No Gene Flow: no migration (no alleles moving into or out of the population)
  • No Drift: the population is large enough to eliminate drift (changes in allele frequencies due to random events)
  • All individuals in the population are mating randomly
• Founder Effect occurs when a few individuals form a new population
• Bottleneck is when a population is dramatically reduced in size
• Scienceo Hypotheses – Best guess that is testable. A useful hypothesis in science will betestable with experiments.o Laws – Describes repeated patterns in natureo Theories – an explanation of a pattern that has been so thoroughly testes thatmost scientists consider it true and correct a whole body of knowledge.
• Humans are diploid, meaning they have 2 copies of each chromosome called homologous chromosomes, totaling 46 chromosomes in 23 pairs
• An allele is a different version of one gene, represented by letters (e.g., A or a)
• In a diploid organism, there are two alleles for each gene:

  • Homozygous: both alleles are the same (AA or aa)
  • Heterozygous: both alleles are different (Aa)
• Genotype refers to all the genes and alleles in an organism, representing what genes/alleles an organism has (e.g., AA or aa or Aa)
• Phenotype is the physical expression of the genes/alleles in an organism
• Mendel's Laws:

  • Law 1: Alleles for one gene separate independently into different gametes
  • Law 2: A pair of genes are separated independently
• Punnett squares are used to predict the outcomes of genetic crosses
• Phenotype frequencies and genotype frequencies are important in understanding inheritance patterns