Approximately 65.5 million years ago the Earth experienced a permanent loss of major groups of organisms during an event called ________
a. speciation
b. continental drift
c. genetic equilibrium
d. mass extinction
e. directional selection
d
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Consider the following two statements about protein structure: 1) All polypeptides have tertiary structure. 2) All proteins have quaternary structure. Determine which one of the statements below is correct
A. Statements 1) and 2) are both true. B. Statements 1) and 2) are both false. C. Statement 1) is true; statement 2) is false. D. Statement 1) is false; statement 2) is true.
Which of the following sequences is a palindrome?
A. GGAACC B. AATTCC C. TCATGA D. GTTACC E. GGGAAA
Which of the following are not topoisomers?
A. two molecules having the same number of base pairs but different linking numbers B. two molecules having a different number of base pairs but the same linking number C. two molecules having the same number of base pairs, but one is positively supercoiled and the other is negatively supercoiled D. two molecules having the same number of base pairs, but one is underwound and the other is overwound E. All of these choices are topoisomers.
By one estimation, the gross global ecosystem valuation is ____
a. equivalent to the total carbon dioxide processed by all ecosystems b. equivalent to the total amount of carbon fixed c. equivalent to the value of all goods produced on Earth d. greater than the value of all goods produced on Earth e. less than the value of all goods produced on Earth