Answer: Maybe you think that snails, clams, mussels, squid, and octopods are very different. Yet, they are all in the same category of animals known as mollusks and are structurally similar. ... Mollusks usually, but not always, have a shell, which is secreted by a body wall called the mantle.
Answer:
- DNA to be cloned
- mature mammalian mRNA is isolated
- reverse transcriptase, provided with a primer, synthesizes a strand of cDNA without introns
- the mRNA is hydrolyzed by raising the pH
- a primer site is created on the ssDNA
- a complementary DNA strand is synthesized, forming a ds cDNA molecule.
- dsDNA
Explanation:
cDNA is the acronym for complementary DNA. This DNA is a single or double stranded moolecule that is synthesized from a messenger RNA molecule. This molecule is used in studies that aim to clone eukaryotic genes in prokaryotic individuals. The result of this is the expression of a protein from a eukaryotic individual in prokaryotic individuals.
To form a double-stranded cDNA molecule, the following steps would be required:
- DNA to be cloned
- mature mammalian mRNA is isolated
- reverse transcriptase, provided with a primer, synthesizes a strand of cDNA without introns
- the mRNA is hydrolyzed by raising the pH
- a primer site is created on the ssDNA
- a complementary DNA strand is synthesized, forming a ds cDNA molecule.
- dsDNA
Answer:
A. The whale is heterotrophic.
Explanation:
The whale is an aquatic animal that is heterotrophic in nature. Heterotrophic means that this animal lacks the ability to manufacture its own food because it depends on plants and animals as a source of food energy. Since the Whale is dependent on phytoplankton for food, this means that it is not a producer of food and as such is heterotrophic.
Phytoplankton is a marine alga. Algaes are prokaryotes and this means that they are unicellular animals without a membrane-bound nucleus. The Cell wall is mostly a characteristic of plants. So the first option is a perfect description of the whale and not its food source which is the phytoplankton.
Answer:
A) nutrient A only
Explanation:
In this case, enzyme A is required for the digestion of nutrient A, thereby evidencing that the mutation affects the enzymatic pathway and the mutant strain only can grow by supplementation with this nutrient. In molecular biology, mutant strains are useful to study enzymatic functions (for instance, the role of enzyme A in nutrient assimilation), as well as to examine downstream signaling pathways.
In experimental design, spontaneous mutations are induced to study their effects on the phenotype. Subsequently, reverse mutations may also be induced to reverse the forward mutation, thus restoring the original wild-type phenotype.
