Answer:
All arthropods have an exoskeleton.
Explanation:
The correct answers are:
2) Peptide bonds form from nucleophilic attack by an electron pair on an alpha - amino nitrogen atom on an alpha - carboxyl carbon atom of another amino acid and
4) Peptides are polymers of amino acids.
A peptide bond is an amide type of covalent chemical bond. It is formed between two amino acids: C1 (carbon end) of one alpha-amino acid and N2 (nitrogen end) of another. Peptide bonds are the basis for the formation of a peptide chain and consequently protein. Formation of peptide bond is a condensation process, meaning that when two amino acids combine and link, water molecule is released and dipeptide is a product of that reaction.
I think the answer you are looking for is that the stomach is the fourth level of organization.
B
Information is encoded in DNA, then copied onto RNA during transcription. Then, ribosomes convert the information carried in RNA into a protein, in the process of translation. Also, A and D could be ruled out because DNA and RNA are solely involved with proteins, but polysacchariades are chains of sugars.
The right answer is The cells are damaged.
Take the example of skin cells.
The skin consists of two tissues:
* the outermost, the epidermis, resting on a vascularized connective tissue,
* the dermis.
In the epidermis, which includes several layers of cells, the outer layer is formed of dead cells that are desquamating and are constantly being replaced from proliferating basal cell cells. So, in normal conditions, the epidermis is in constant renewal.
On the other hand, when accidentally, the upper parts of the epidermis are damaged, for example, a slight abrasion or of a burn, the destroyed portion is regenerated (replaced) thanks to an accelerated proliferation of basal epidermal cells .
