Download Biology 101-003

Science 103 (Integrated Science II) Spring 2006: Study Guide for Exam 3
1. Radiation
 See practice test.
2. Cell division (P 423-425, 512-524, & 570)
 Why do somatic cells divide?
 What 2 stages are involved in the prokaryotic life cycle?
 Why is the eukaryotic cell cycle is more complex than the prokaryotic cycle?
 Know all the stages of the eukaryotic cell cycle and what occurs at each stage. Know what
proportion of the cell cycle is taken up by interphase. Know how the cell cycle is controlled,
including the 3 checkpoints, and what occurs when conditions are or are not favorable at each
checkpoint. Know what is assessed at each checkpoint (eg. has all the DNA replicated?). Know
why it is important for cells to control their division rate.
 Know the structure of chromosomes, including why histones are required, how they are able to
wind up the DNA, what homologous chromosomes are, and how chromosomes duplicate
(including when they duplicate and what the centromere and sister chromatids are). Know how
many chromosomes somatic human cells have and what monosomy and trisomy are.
 What is mitosis? Know the stages of mitosis, what occurs at each stage, and the order in which
the stages occur (be able to draw and label the stages of both mitosis AND meiosis – practice
from memory!!!). Also know that mitosis and meiosis are continuous processes. Know what the
kinetochores and the kinetochore microtubules are. Know the function and composition of the
contractile belt and what a cleavage furrow is. Know how cytokinesis in plant and animal cells
differs, why they differ, and what structures are responsible for the process in each cell type.
 Know the function of programmed cell death and what types of cells do not have a finite number
of divisions. Be able to define cancer and tumors, and know the differences between benign and
malignant tumors. Know the characteristics and causes of cancer. Understand why cancer occurs
less frequently than one would expect (be able to give reasons). Know what tumor suppressor
genes are, the functions of the p53 protein, and the actions of the protein when its activity is
normal. Also know what happens when the p53 gene is mutated and how this can result in cancer,
including what Li Fraumeni syndrome is. Why does cigarette smoking frequently result in
cancers?
 Know what gametes and fertilization are and to what the term “alternation of generations” refers.
Know the animal life cycle (be able to draw and label) and what haploid and diploid cells are
(know what ploidy means).
 What are the 3 defining features of meiosis? Know what maternal and paternal chromosomes are,
how crossing over occurs, and between what and when in meiosis it occurs. Also know the
function of crossing over, and what synapsis is. Know the stages of meiosis, what occurs at each
stage, and the order in which the stages occur (again, be able to draw and label!). How does
meiosis result in genetic variation? What other process in sexual reproduction results in genetic
variation? Be able to describe independent assortment. Know the differences between mitosis
and meiosis. Finally, know the evolutionary consequences of sex.
 What is gametogenesis?
 What is spermatogenesis? How many daughter cells are produced by this process? Where in the
body does it occur? Be able to describe the structures and functions of the seminiferous tubules
and the epididymis.
 What are spermatogonia? What is their ploidy? Their function? What are primary and secondary
spermatocytes? What are spermatids? What is their ploidy? How do they change as they mature?
 Be able to describe the structure (and label diagrams) of sperm. What is the acrosome? What is
its function?
 What is oogenesis? How many daughter cells are produced by this process? Where in the body
does it occur? In what stage of meiosis are the oocytes of a newborn baby girl? What are
primordial follicles?
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What is the function of FSH? What are polar bodies? What is their function? In what stage of
meiosis are secondary oocytes?
What is ovulation? What is the corpus luteum? What is its function? What process will result in
an oocyte completing meiosis II? If an ovum is fertilized how is the corpus luteum maintained?