The correct answer is the organ.
The multicellular species are formed of various parts, which are required for survival. These parts are differentiated into the levels of the organization. There are five different levels, which are named as cells, tissue, organs, organ systems, and organisms.
When two or more layers of tissue function together, they produce an organ. All the animals comprise vital organs, without which they cannot survive. These include the kidneys, liver, lungs, brain, and heart.
<h2>Endothermic Process</h2>
Explanation:
An example of endothermic process is :
Heat is needed for water to boil.
Endothermic process can be defined as a process in which heat energy is absorbed from the surrounding that bring about changes in the molecular level like breaking chemical bonds, inter-molecular force of attraction etc.
Boiling of water is an endothermic process because during this process water absorbs heat , its kinetic energy increases and then it boils.
The antigen-binding sites of an antibody molecule are formed from the molecule's variable regions which are described as so because their amino acid sequences can be different on different antibodies.
The specificity of antibodies is determined by the variable regions found at their endpoints. Antibodies are specialized proteins secreted by B-cells of the immune system. They are also called immunoglobulins. They contain four polypeptide chains that comprise two heavy chains and two light chains to form a Y-shaped molecule.
The variable regions, more specifically the hypervariable regions of an antibody, have a high ratio of different amino acids with the most common amino acids provided in one place. The variable region serves as the antigen-binding site while the constant region found below the variable region is determined to invade the antigen.
Antibodies are preserved in our body to identify the antigen the next time it encounters. They send the signals to the other body parts to reject the antigen and invade it.
To know more about variable regions of antibodies, refer to the following link:
brainly.com/question/17439586
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A stamen is the name for male reproductive parts of the flower which consists of an <u>Anther and Filament</u>.