Spiegelman and colleagues demonstrated natural selection with RNA molecules. How did they satisfy the three ingredients for natural selection?
What will be an ideal response?
ANS:
For natural selection to occur, there must be variation, heritability of the variation, and differential fitness. The replicase in their experiment induced mutations and thereby produced variation. The mutations were heritable when the RNA molecules were replicated. Differential fitness resulted because short sequences rep-licated faster than longer ones, but sequences that were very short were eliminated through detrimental ef-fects of mutation.
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Microarrays are created by robotically placing DNA on to a microscope slide and probing with
A. RNA from the tissue of interest. B. another DNA from the tissue of interest. C. SNPs from the tissue of interest. D. STSs from the tissue of interest. E. clone-by-clone sequencing.
Many normal genes that have important functions in cells sometimes acquire mutations that cause the products of these genes to have negative effects, including the development of cancer. These genes are called:
A. oncogenes. B. proto-oncogenes. C. tumor suppressor genes. D. viral genes.
RNA interference (or RNAi) is a popular research tool used in biomedical research. It has great potential as it allows researchers to "knock down," or silence, genes of interest. For, example, it could be used to block expression of a gene that plays a role in a certain cancer. In the lab, researchers can design synthetic double stranded RNA that then binds the mRNA of interest and leads to its
destruction. Which mechanism within a cell also leads to mRNA destruction? Explain how this mechanism works. What will be an ideal response?
This phylum of nonvascular plants has about 6000 known living species. It includes the genus
Marchantia, whose members can reproduce asexually via cups called gemmae.
a. Hepatophyta b. Pterophyta c. Bryophyta d. Lycophyta e. Anthocerophyta