FOLLOW-UP NOTES on the BIOLOGY 101 SECOND EXAM
EXAM SCORING:
Fill-ins
10 points
Definitions
20 points
Long answers 30 points
_40 points added free
TOTAL:
100
EXAM SCALE:
89-99 A-, A, A+
79-88 B-, B, B+
70-78 C-, C+
60-69 D
14 students
9 students
11 students
2 students
NOTES ON CERTAIN SELECTED QUESTIONS:
The most often missed fill-in was about what bacteria supply to plants. Answer on p. 374-375.
Essential points to mention for certain oft-chosen definitions:
Genetic drift: random changes, small populations, isolated populations
Decomposers: live on decaying matter and break it down
Placebo: inert medication with no active drug ingredient
Circadian: rhythm of about 24 hours duration
Specific immunity: specific, has memory, body-wide, stronger 2nd time
Bioaccumulation: increasing concentrations of toxins passing up the food chain
Schizophrenia: excess of dopamine, frequent hallucinations & delusions
Instinct: behavior that is both innate and complex
Inflammation: redness, swelling, pain, increased temperature
Drug: any substance that provokes a physiological response
Essential points that should have been mentioned for certain long answers:
1. High UV levels (not heat) near Equator increase risk of skin cancer in light-skinned people;
low UV levels at high latitudes increase vitamin D deficiency in dark-skinned people.
8. Recognized benefits of marijuana include decreased eyeball pressure in glaucoma, also
stimulation of appetite in AIDS patients and cancer chemotherapy patients. Pain relief
is often claimed but also disputed. Biggest problem is lung cancer & other respiratory
problems from the smoke (worse than for tobacco), also weight gain, also interferes with
testosterone in men (frequent breast enlargement). Addiction is also a big problem.
Driving under the influence is NOT a big problem because reaction time is not impaired.
Uncertain problems include keeping it away from people who don't really need it, including
possible theft, re-sale, and over-prescription.
9. Most harm from tobacco comes from tars and other carcinogens: cancers, emphysema, etc.
Nicotine is addictive and also increases heart attack rates; addiction makes quitting hard.
10. Axon membrane is normally positive on outside (sodium ions). Impulse is a temporary reversal
of electrical polarity that travels along the membrane in a wave when sodium ions enter; it can
also travel in "saltatory" (jumping) conduction from one node of Ranvier to the next.
(Neurotransmitters are active at the synapse between neurons, not along the axon.)