Which of the following is true of retroviruses? (3 points) Retroviruses use reverse transcriptase to make viral DNA in a host, and the viral DNA becomes a permeant resident of the host cell.
Retroviruses use DNA polymerase to make viral DNA in a host, and the viral DNA becomes a provirus of the host cell.
Retroviruses use the same machinery as prokaryotes and follow the same process to make RNA.
Retroviruses have an RNA genome instead of DNA but use all of the same enzymes as eukaryotes.

Match the order of the levels of organization in nature with the correct description. example: atoms are fundamental units of matter= level 1levels- 2,3,4,5,6,7,8.now what levels are these? population consists of organismscells consist of moleculesecosystems consist of communities interacting with there environmentmolecules consist of atomsthe biosphere consist of all ecosystems on earthcommunities consists of populationorganisms consist of cells

Our planet has experienced five major extinctions in the four billion year history of life. the first, 450 million years ago, occurred shortly after the evolution of the first land-based plants and 100 million years after the cambrian explosion. the second extinction occurred 350 million years ago, causing the formation of coal forests. next earth experienced two mass extinctions during the triassic period, between 250 and 200 million years ago. the fifth mass extinction occurred 65 million years ago, ending the reptilian dominance of the earth. according to richard leakey, the sixth mass extinction is happening right now. leakey suggests that we, the human race, are the cause. each year, at our hand, approximately 50,000 species vanish from earth. he believes that man is destroying earth at a rate comparable with the impact of a giant asteroid. leakey's statistics indicate that 50% of earth's species will become extinct within the next 100 years assuming leakey's hypothesis of a sixth mass extinction to be true, how will we expect the model to change? a) a sharp spike in the graph approximately 100 million years from now b) a dip in the graph, followed by a sharp spike about 100 million years from now c) a sharp spike in the graph immediately following the "0" location of the x axis d) a plateau following the "0" mark on the x axis, followed by a gradual rise to a new peak

Accuracy in the translation of mrna into the sequence of amino acids in a polypeptide depends on specificity in which of the following? 1) binding of ribosomes to mrna 2) shape of the a and p sites of ribosomes 3) attachment of amino acids to trnas 4) bonding of the anticodon the codon and the attachment of amino acids to trnas