The right answers are:
A-present in eukaryotic genomes ==> Both exons and introns
B-generally absent from bacterial genomes ==> Introns
C-part of the final mRNA strand ==> Exons
D-code for an amino acid sequence ==> Exons
E-removed from initial mRNA strand prior to translation ==> Introns
F-present in the DNA used as the template for transcription ==> Both exons and introns
In the genes of eukaryotic organisms, the exons are the segments of an RNA precursor that are conserved in the RNA after splicing and that are found in mature RNA in the cytoplasm. The segments of the RNA precursor that are removed during splicing are called in opposition to introns. Exons are mainly found in messenger RNAs (mRNAs) encoding proteins. Some mRNAs may sometimes undergo an alternative splicing process in which one or more exons may be excised or some introns preserved in rare cases.
Answer:
D) Because sticky ends can be temporarily held together by hydrogen bonding between the two strands.
Explanation:
Restriction enzymes cut the DNA at specific restriction sites and by the mechanism of action they can form two types of ends:
- sticky ends-single-stranded overhangs are formed
- blunt ends-without overhangs.
The main advantage of sticky ends (their overhangs) is that they can complementary bind to another overhand formed by the same restriction enzyme. So, for example in cloning, if the DNA of interest and plasmid vector are cut with the same restriction enzyme, that forms sticky ends, fragment of DNA will fit into a bacterial plasmid in one direction.
On the other hand, blunt ends can be inserted into vector in both directions: head-to-tail or tail-to-head.
Answer:
If it is a gene mutation then it is during the S phase, and if it is a chromosome mutation, then during metaphase or anaphase.
Explanation:
The cryosphere is the frozen water part of the Earth system. Beaufort Sea, north of Alaska. One part of the cryosphere is ice that is found in water. This includes frozen parts of the ocean, such as waters surrounding Antarctica and the Arctic.
