biology exam number 2

  1. Conditions for a happy enzyme
    • 1. pH
    • 2. Temperature
    • 3. Salt concentration
    • 4. Helpers such as cofactors and co enzymes
  2. Do plants cells perfer to be hypertonic, isotonic or hypotonic
    Hypotonic- Like to have a lot of water and little soulte
  3. What is the problem for C3 PLants in hot/dry weather?
    Stomata close to reduce water loss and o2 build up
  4. What are the mendelian laws of inheritence?
    Each parent contributes equally to offspring(correct)

    Hereditary blend in the offspring(in correct). It was thought that once hereditary elements had blended they could never be separted; 

    He worked on a garden pea- He could control pollination and fertilization by removing male organs and manually pollinating the flowers
  5. Why did mendel choose the garden Pea?
    - Rapid growth; Produces alot of seeds; requires little space

    - naturally self pollinating, but pollination and fertilization can be controlled (done by Mendel) to be sure of offspring and parents. (done by Mendel)

    • Has distinct characteristics
    • Physical features: Folower color and traits form of a character (ex: purple; white; wrinkled smooth) Heritable traits are passed from parents to offspring.
  6. Mendel looked for well- defined, true -breeding traits- the observed trait is the only one present for many generations.
    true-breeding strains were isolated by inbredding and selction
    • He concetrated on 7 characteristics:
    • Pollen from one parent was transferred to the pistil of the other parent.  Parental generation = P.​Resulting offspring = first filial generation or F1.​If F1 plants self-pollinate, produces second filial generation or F2.​He first crossed plants differing in just one trait; the F1 generations are called monohybrids.​The monohybrids were then allowed to self-pollinate to form the F2 generation: a monohybrid cross.​Mendel repeated this for all seven characters.
  7. One trait of each pair disappeared in the F1 generation and reappeared in the F2—these traits are recessive.​The trait that appears in the F1 is the dominant trait.​The ratio of dominant to recessive in the F2 was about 3:1.​Mendel proposed:​that heritable units were discrete particles—the particulate theory.​each plant has two particles for each character, one from each parent (we call this diploid).​During gamete formation only one of these paired units is given to the gamete (we call this haploid)
    the true-breeding plants in the P generation had two identical copies of the particle (gene) for each character.​Example: Spherical SS; wrinkled ss​gametes from SS will have one S​gametes from ss will have one s​offspring (F1) will be Ss​   S is dominant; s is not expressed in F1.​
  8. Alleles: different forms of a gene​Homozygous: an individual having two copies of the same allele of a gene in the genome.  These individuals are true-breeding.​SS ss​Heterozygous: an individual carrying two different alleles of the same gene.​Ss
    Dominant allele: allele that is preferentially expressed in an organism that also carries another allele of the same gene.​Recessive allele: allele that is not expressed or weakly expressed.​​​S   s
  9. Phenotype: Physical appearance of an organism (e.g., spherical seeds).​Genotype: The genetic makeup (e.g., Ss).​Spherical seeds can be the result of two different genotypes—SS or Ss.
    Allele combinations can be predicted using a Punnett square.
    slide 16 mendels first exp:
  10. What commonly limits the reproduction of a prokaryotic cell by binary fission?
    Reproductive signals
  11. Why must DNA be replicated and segregated before the cell can divide?
    The cells genetic material must be duplicated so that each of the two new cells will have a complete identical sets of genes
  12. Why are DNA replication and cell division more complex in eukaryotes than in prokaryotes?
    prokaryotic divdes by binary fissioneukaryotic cells divide by mitosis followed by cytokinesis
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biology exam number 2
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