EXAM 1 BIO 1500 STUDY GUIDE
Natural Selection – Process by which things adapt in their environment Evolution and Natural Selection are not the same!
Polymorphic (phenotype) – Presence of one allele of a gene at a frequency greater than newly arising mutations
MUTATION RATE IS SLOW!
1. Why is genetic variation in a population necessary for evolution? If you don’t have variation, there is nothing to select… There has to be differences for a selective process.
∙ Assortative – phenotypically similar, increases proportions of homozygous individual
∙ Dissortative – phenotypically different, produces excess of heterozygous
Genetic Drift – Random occurrences that change frequency drastically alone, especially in small populations
∙ Founder Effect
∙ Bottleneck Effect
Fitness – number of surviving offspring left in the next generation
∙ Constructive – spread beneficial mutation to other populations ∙ Constraining – can impede adaptation by continual flow of inferior alleles in populations
Gene flow will cause mutation to spread in other locations
∙ Multicellular haploid and diploid stages
∙ Trend toward more diploid embryo protection Don't forget about the age old question of What is the concept of yin and yang?
∙ More fit overtime
∙ Trend toward smaller haploid stage
We also discuss several other topics like Who discovered cells by observing the slices of cork?
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Know the steps to the plant life cycle
Haplodiplontic Life Cycle
∙ Multicellular diploid sporophyte stage
∙ Produce haploid spores by meiosis (sporophyte stage)
∙ Diploid spore mother cells undergo meiosis in sporangia ∙ 4 haploid spores are produced
∙ Multicellular haploid gametophyte stage
∙ Spores divide by mitosis
∙ Produces gametes
∙ Gametes fuse to form diploid zygote
*Moss – large gametophyte, small dependent sporophyte
*Angiosperms – small dependent gametophyte, large sporophyte
2. How would you distinguish a small aquatic tracheophyte from a freshwater algae plant?
Tracheophytes contain xylem and phloem, and algae has not developed these because they are non-vascular.
∙ Bryophytes: closest living descendants of first land plants (non vascular spores) Don't forget about the age old question of What is the formula for linear charge density?
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o Lack of xylem and phloem
o No roots, but contain rhizoids
∙ Mycorrhizal Associations – important in enhancing water uptake in early plants and in bryophytes
∙ Not true leaves – no vascular tissue
∙ Gametophytes consist of small green leaf-like structures around stem like axis
∙ Have stomata (first plant to have)
∙ And cuticle to prevent dessication
Archegonia – female gametangia
Antheridia – male gametangia Don't forget about the age old question of What is sumerian art?
∙ Form gametangia in umbrella shaped-like structures