Example of Internal Stimulus - Option A
A decrease in oxygen levels in the blood during exercise is an example of an internal stimulus. It is happening within the organism itself, it will be internal stimulus. But a sudden change of air temperature is not occuring within the body of organism.
It is the change outside so it is external. An artificial light that attracts insects and an increase in the amount of water available to plant. Both are happenings which occur outside the body hence both are external stimulus. Only a decrease in oxygen levels in the blood during exercise happens inside the body so it is only internal stimulus.
Answer:
Genetic code comprises 64 codons, out of which 61 codes for 20 amino acids, while the remaining three codons do not code for any amino acids. In nature, only twenty standard amino acids prevail.
A standard amino acid is considered as an amino acid that possesses an alpha-carboxyl and alpha-amino acid, and which are found in the proteins. Though there are some of the compounds that possess alpha carboxyl and alpha-amino group but are not regarded as standard amino acids, as they do not take place in proteins like the standard one does, and these are termed as non-standard amino acids.
The frequency of these non-standard amino acids in the proteins is less and they do not comprise all the characteristics demonstrated by the standard amino acids. The genetic code is degenerative and because of this, a single amino acid is encrypted by more than one codon.
The non-standard amino acids do not exhibit the corresponding amino acids, which can code for them and they are not mediated by the t-RNA's to the location of translation, as there is no corresponding tRNAs for them. Thus, genetic code utilizes only the twenty standard amino acids.
Answer:
Answer in explanation
Explanation:
Capillary action: Inside the stem, there are tube-like transport tissue, called xylem, that brings water and nutrient to different parts of the plant. Water molecules are attracted to the surface of the xylem cells by weak electrical attractions. This sticky property is called adhesion. Water automatically moves up the xylem due to adhesion and the resulting movement is called capillary action1.
Cohesion: Water molecules are not only attracted to the surface of xylem (adhesion), but they are also attracted to one another. This property is called cohesion. Because of cohesion, water molecules fill the column in the xylem as they move up and act as a continuous stream of water.
Transpiration: Water evaporates from the plant through transpiration. As water evaporates in the petals or any part of the plant exposed to air, a negative pressure is created in the xylem, resulting in suction pulling the water upward just like you draw water upward when you suck on a straw.
C, they both have cells with membrane bound organelles
The linear sequence of amino acids within a protein is considered the primary structure of the protein. Proteins are built from a set of only twenty amino acids, each of which has a unique side chain. The side chains of amino acids have different chemistries.