Unformatted text preview: nisms, e.g. hormones
from endocrine cells, digestive secretions from
exocrine cells. • Expulsion of wastes from unicellular organisms, e.g. Paramecium and Amoeba expelling
residues from food vacuoles.
4. 5. Any type of cytosis (unlike diffusion) is an active
process involving the use of ATP. Low oxygen inhibits
oxidative metabolism and lowers the energy yield from
the respiration of substrates (ATP availability drops).
(d) acquire mutations. Mutations to the proto-oncogenes,
with the consequent formation of oncogenes, results
in uncontrolled cell division. Mutations to the tumorsuppressor genes results in a failure to regulate the
cell repair processes and a failure of the cell to stop
dividing when damaged. Levels of Organization (page 32)
1. (a) Organ system: Respiratory system, muscular
system, nervous system, reproductive system.
(b) Organs: Brain, heart, spleen, pancreas, liver,
(c) Tissues: Blood, bone, cardiac muscle, cartilage,
(d) Cells: Leucocyte, mast cell, neuron, Schwann
(e) Organelles: Lysosome, ribosomes, peroxisome.
(f) Chemical: Epinephrine (adrenaline), collagen,
DNA, phospholipid, ATP. 2. Histology Oxygen: Diffusion.
Cellular debris: Phagocytosis.
Glucose: Facilitated diffusion. Mitosis and the Cell Cycle (page 29) Anatomy and Physiology 1. (a) The final chromosome status of a cell following
mitosis is exactly the same as its parent. In
contrast, a cell following meiosis has half the
chromosome complement of the parent, i.e. it
goes from diploid to haploid.
(b) The biological role of mitosis is in growth,
development, and repair of tissues, whereas the
role of meiosis is to produce haploid gametes for
the purposes of sexual reproduction. 2. Required answer in bold: The DNA must be
replicated to form a second chromatid. The
chromosomes must condense to avoid tangling. 3. A. Interphase: The stage between cell divisions
(mitoses). Just before mitosis, the DNA is
replicated to form an extra copy of each
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- Winter '13