The correct answer is option A, that is, only DNA comprises nucleotides.
Nucleotides refer to the organic molecules, which function as the monomer units for producing the nucleic acid polymer DNA. Nucleotides are the building elements of nucleic acids. They are comprised of three subunit molecules, that is, a five-carbon sugar, a nitrogenous base, and at least one phosphate group.
Answer:
<em>The correct option is C) dog</em>
Explanation:
Eukaryotes can be defined as organisms which have a proper nucleus which is enclosed in a membrane. Prokaryotes can be defined as organisms which do not have a nucleus. The genetic material of prokaryotes is present in the cytoplasm. The genetic material of eukaryotes is present enclosed in the nucleus. Examples of eukaryotes include plants and complex organisms like dogs, cats etc. Hence, option C is correct.
Other options are not correct because the organisms mentioned in them are prokaryotes.
D. <span>Only in the absence of dominant genes for the same trait.
Recessive genes are absent of something, so both genes have to be absent of that particular trait.</span>
Answer:
Ligand-receptor interaction is the first interaction that triggers cell signalling.
Explanation:
Ligands are the hormones, drugs or neurotransmitters that specifically bind with receptors present in cell surface to initiate cell signalling. Ligand binding to the receptor is reversible. Binding of the ligand to the receptor can activate or inactivate receptor. Activation may lead to cell signalling pathways. Inside cells, there are secondary molecules which on activation starts a cascade of reactions. which in-turn regulate the function of the ligand molecule.
Best Choice:
Ligand-receptor interaction is the first interaction that triggers cell signalling.
The food chain is very important to ecosystems.
