The structure of a typical antibody molecule
Antibodies are the secreted form of the B-cell receptor. An antibody is identical to the B-cell receptor of the cell that secretes it except for a small portion of the C-terminus of the heavy-chain constant region. In the case of the B-cell receptor the C-terminus is a hydrophobic membrane-anchoring sequence, and in the case of antibody it is a hydrophilic sequence that allows secretion. Since they are soluble, and secreted in large quantities, antibodies are easily obtainable and easily studied. For this reason, most of what we know about the B-cell receptor comes from the study of antibodies.
Antibody molecules are roughly Y-shaped molecules consisting of three equal-sized portions, loosely connected by a flexible tether. Three schematic representations of antibody structure, which has been determined by X-ray crystallography, are shown in Fig. 3.1. The aim of this part of the chapter is to explain how this structure is formed and how it allows antibody molecules to carry out their dual tasks—binding on the one hand to a wide variety of antigens, and on the other hand to a limited number of effector molecules and cells. As we will see, each of these tasks is carried out by separable parts of the molecule. The two arms of the Y end in regions that vary between different antibody molecules, the V regions. These are involved in antigen binding, whereas the stem of the Y, or the C region, is far less variable and is the part that interacts with effector cells and molecules.
Although the options are not provided, the statement that applies only to anaerobic respiration and not to aerobic respiration is
has commercial uses
Anaerobic respiration finds its major use in the production of alcohol from yeast in a process known as fermentation. The yeast or other microorganisms are provided a substrate to respire anaerobically on and they produce ethanol as a result of this process.
D- During interphase, when the cell is not dividing, chromatin is less tightly packed compared to our chromosomes, which allows transcription to occur.
Answer:
Embryological evidence
Explanation:
Deuterostomes is a group that includes echinoderms, hemichordates, and chordates. Although these animals exhibit a wide variety of body plans, they share a mouth secondarily formed during embryo development, which it is believed to be an evolutionarily derived character present between a common ancestor and all its descendants (i.e., a synapomorphy). This oral cavity is formed by the invagination of the ectoderm layer opposite to the blastopore of the gastrula.
I would think on of the reasons is because the food that mice eat has a greater variety, in the sense that while a lion may only eat meat and have to catch its prey the mice can eat without relying on other animals. Lions also have more competition between other animals like them for example cheetahs and leopards on the other hand a mice is more independent. On period where food is scarse mice can get on with eating what the earth provides like plants lions can’t.
