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
If you want to learn more check out What is the concept of yin and yang?
∙ 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 We also discuss several other topics like What is the average size of organelles?
Gene flow will cause mutation to spread in other locations
∙ Multicellular haploid and diploid stages
∙ Trend toward more diploid embryo protection
∙ More fit overtime
∙ Trend toward smaller haploid stage
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 If you want to learn more check out How does the history of psychology connect to philosophy?
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*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. If you want to learn more check out What is a binomial expression?
∙ Bryophytes: closest living descendants of first land plants (non vascular spores)
o Lack of xylem and phloem Don't forget about the age old question of When was the paleolithic era?
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
∙ Form gametangia in umbrella shaped-like structures