BOT 101 exam 2

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BOT 101 exam 2
2011-03-30 06:56:03
botany word bank

Exam 2
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  1. Chromosome
    One of several rod-shaped bodies in the cell nucleus that contain the hereditary units (genes)
  2. Mitosis
    The division of the cell nucleus resulting in two daughter nuclei, each with the same number of chromosomes as the parent nucleus.
  3. Meiosis
    Process in which a 2n cell undergoes successive nuclear divisions, potentially producing four n nuclei; leads to formation of spores in plants.
  4. Allele
    One of two or more alternative forms of a gene.
  5. Gene
    A discrete unit of hereditary information that usually specifies a polypeptide (protein).
  6. Deoxyribonucleic Acid (DNA)
    A nucleic acid present in a cell's chromosome that contains genetic information.
  7. Semiconservative replication
    The type of replication characteristic of DNA, in which each new double-stranded molecule consists of one strand from the original DNA molecule and one strand of newly synthesized DNA.
  8. Modern Synthesis Theory
    A comprehensive, unified explanation of evolution based on combining previous theories, especially of Mendelian genetics, with Darwin's theory of evolution by natural selection.
  9. Systematics
    The scientific study of the diversity of organisms and their natural (evolutionary) relationships.
  10. Phenotype
    The physical expression of an individual's genes.
  11. Genotype
    The genetic makeup of an individual.
  12. Homozygous
    Possessing a pair of identical alleles for a particular gene. (ex: YY or yy)
  13. Heterozygous
    Possessing a pair of unlike alleles for a particular gene. (ex: Yy)
  14. True breeding strain
    A genetic strain of an organism in which all individuals are homozygous at the loci under consideration.
  15. Polygenes
    One of two or more pairs of genes that affect the same character in additive fashion.
  16. Dominant
    Said of an allele that is always expressed when it is present.
  17. Recessive
    Said of an allele that is not expressed in the presence of a dominant allele.
  18. Pollination
    In seed plants, the transfer of pollen grains from the anther to the stigma.
  19. Gene pool
    All the alleles of all the genes in a freely interbreeding population.
  20. Species
    A group of organisms with similar structural and functional characteristics that in nature breed only with one another and have a close common ancestry.
  21. Population
    A group of organisms of the same species that live in a defined geographic area at the same time.
  22. Hormone
    An organic chemical messenger that regulates growth and development in plants and other multicellular organisms.
  23. Auxin
    A plant hormone involved in growth and development, including stem elongation, apical dominance, and root formation on cuttings.
  24. Ethylene
    A gaseous plant hormone involved in growth and development, including leaf abscission and fruit ripening.
  25. Female floral parts
    • Pistil (consisting of one or more carpels)
    • Carpel: The ovule-bearing reproductive unit of a flower.
    • Stigma, style, ovary, ovules
    • refer to pg. 177
  26. Male floral parts
    • Stamen: the pollen-producing part of a flower.
    • Pollen grain: each will produce two sperm cells and a pollen tube
    • Anther, filament
    • refer to pg. 177
  27. Gregor Mendel - Father of Genetics
    • (1822 –1884)
    • Catholic Monk, observed similarities from parental pea plants to next generation (F1 & F2).
    • Understood that there was something determining predictable inheritance.
  28. Charles Darwin & Evolution
    • 1836 Returned from his travels on the Beagle and all the pictures, notes and OBSERVATION.
    • Theory that the different finches he saw throughout the Galapagos islands could have originated from a common ancestor.
  29. Natural selection
    Mechanism of evolution in which individuals with inherited characteristics well suited to the environment leave more offspring than do individuals that are less suited to the environment.
  30. Adaptation
    An evolutionary modification that improves an organism’s chances of survival and reproductive success.
  31. Segregating alleles
    The Law of Segregation of Alleles according to Mendel is that, allele pairs separate (or segregate) during gamete formation, and randomly unite at fertilization.
  32. Genetic variation
    • Variations of genomes between members of species, or between groups of species thriving in different parts of the world as a result of genetic mutation.
    • Genetic diversity in a population or species as a result of new gene combinations (e.g. crossing over ofchromosomes), genetic mutations, genetic drift, etc.
    • Important in maintaining biodiversity among species.