Mito P1
_____ use cell division for growth, maintenance, and repair.
Multicellular organisms
What is binary fission?
When bacteria divide into two
Major goal of meiosis?
Produce offspring with unique combination of genes inherited
What is Turner Syndrome?
Female missing an X chromosome; short stature and loss of ovarian function
Genotype vs. Phenotype?
Genotype = Genes of an organism
Phenotype = Visible traits expressed in an organism
Somatic cells vs. gametes?
Body cells/non-reproductive vs. reproductive cells
What is major purpose of mitosis?
Produce 2 identical daughter cells
# chromosomes in gametes vs. # chromosomes when gametes are fertilized?
23 in each gametes, 46 in zygote
1 similarity and 1 difference between mitosis and meiosis?
Mendel's findings with cross of purple and white flower?
3:1 ratio of purple to white flowers
3 phases of interphase and what happens in each?
G1-Growth and organelles duplicated
S-DNA duplicated/synthesized
G2-Enzymes made for cell division
What is a kinetochore?
Protein structure that attaches chromatids to spindle microtubules
Homologous chromosome vs. sister chromatid?
Homologous chromosome = same genes but different versions from mom and dad (alleles)
Sister chromatids = one-half of duplicated chromosome, contain same exact genes
What happens in independent assortment and what is the point?
Chromosomes line up randomly at metaphase plate (so will separate randomly)--> genetic variation in offspring
Dominant vs. Recessive?
Dominant = Allele always expressed
Recessive = Masked by dominant allele; expressed when dominant allele is absent
3 checkpoints and what they check for?
G1-Are conditions favorable for cell division?
G2-Is DNA duplicated correctly?
M-Are chromatids correctly attached to spindle microtubules?
Why are HeLa cells important and what was the ethical issue?
Used to develop polio vaccine and understand HIV; did not get Henrietta's consent and did not inform family until years later
What happens in crossing-over and what is the point?
Homologous chromosomes exchange genetic material--> genetic variation in offspring
3 types of life-cycles?
Diploid-dominant, Haploid-dominant, Alternation of Generations
Incomplete vs. complete dominance?
Incomplete = alleles neither dominant or recessive
Codominance = both alleles expressed equally
4 stages of mitosis?
Prophase- DNA condensed
Metaphase- Chromosomes line up at middle
Anaphase-Chromosomes pull apart
Telophase and Cytokinesis-2 daughter cells
Chromosome --> Chromatin --> Nucleosome --> DNA
4 stages in Meiosis I and major events?
Prophase 1-Crossing over
Metaphase 1-Independent Assortment
Anaphase 1-Homologous chromosomes pull apart
Telophase 1-2 haploid cells
4 stages in Meiosis II and major events?
Prophase II-Nuclear envelope breaks down
Metaphase II-Sister chromatids line up in the middle
Anaphase II-Sister chromatids pull apart
Telophase II-4 genetically distinct cells
Mendel's 3 laws?
Law of dominance-dominant allele expressed
Law of independent assortment-genes assort independently/randomly
Law of segregation-two alleles for a gene separated in gametes