How many types of amino acids human body needed to build proteins?
a. 11
b. 20
c. 2
d. 46
Answer: b. 20
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The first antibiotic to be characterized was a
A) cephalosporin. B) quinolone. C) ?-lactam. D) macrolide.
Answer the following statements true (T) or false (F)
1. A simple dot matrix is the best method to identify homologous sequences from a known sequence. 2. If a gene's sequence is compared among several different vertebrates and they are found to be 95% homologous, one can assume that the genes are derived from the same ancestral gene. 3. Sequences that are alike will produce a horizontal line in a dot matrix analysis. 4. The current genome databases are biased towards species that are important from a research, medical, or agricultural perspective.
Which blood type is the universal recipient?
a. A b. B+ c. AB+ d. AB e. O+
Which feature is not characteristic of all living organisms?
A. All have requirements for energy. B. All must participate in one or more nutrient cycles. C. All have ultimate dependence upon the sun. D. All interact with other forms of life. E. All must reproduce inside of organisms of other species.