Exam 2 (ch 11 pre class)
Which of the following statements is NOT true about sister chromatids?
They are formed when the prokaryotic circular chromosome attaches at the plasma membrane
Which of the following is NOT true about gametes?
They are genetically identical to other gametes formed during meiosis
The second meiotic division resembles mitosis because:
chromosomes decondense during telophase II. sister chromatids are separated during anaphase II to become the chromosomes of the daughter cells. spindle microtubules attach from opposite directions to the centromere of each sister chromatid pair, the daughter cells have the same number of chromosomes as the parent cell
Sexual reproduction results in an increase in genetic diversity because
during prophase I, genes that are paternally and maternally derived recombine so that the gametes have chromosomes that are different from the parents' chromosomes.
Tumor suppressors oppose oncogenes by:
instructing defective cells to die, slowing cell division, repairing mutations, blocking the action of an oncogene
Reproduction by mitotic cell division
results in two daughter cells that are genetically identical. is asexual reproduction. continues in mature adult humans to replace damaged and worn-out cells. persists in mature plant cells for continued growth
Cell division is regulated by
signals about the nutritional status of the cell, growth factor signals, signals that indicate that DNA has been replicated, signals that indicate that the cell has reached a sufficient size during fertilization, the gametes that fuse are random so that a large number of chromosomal combinations are possible in the new organism, during metaphase I, the bivalents line up in a random orientation so that gametes inherit a random set of maternally and paternally derived chromosomes
During meiosis I:
sister chromatids are not separated, non-sister chromatids exchange maternal and paternal DNA, bivalents are formed during prophase I and are taken apart during anaphase I, chromosomes undergo reductional division
The centrosome is
the microtubule organizing center for the mitotic spindle
