D
Explanation:
With the help T cells , B cells make special proteins called antibodies which stick to antigens on surface of germs stopping them in their track.
The smooth endoplasmic reticulum functions in many metabolic processes. It synthesizes lipids, phospholipids as in plasma membranes, and steroids.
Ans.
Diffusion, osmosis, and active transport are mechanism of cellular transport that involves movement of molecules through plasma membrane. Diffusion shows movement of small, hydrophobic particles without the help of protein molecules through cell membrane along the concentration gradient.
Osmosis involves movement of water molecules against concentration gradient (from an area of high solvent concentration to an area of low solvent concentration) through cell membrane.
Active transport shows movement of particles, against the concentration gradient, means from a region of higher to lower concentration of molecules through cell membrane. It involves transport through membrane proteins.
Thus, the part of cell, which is affected by the movement of molecules through osmosis, diffusion, and active transport is cell membrane or plasma membrane.
Hairpin like structures are formed in both DNA and RNA but are common in RNA than in DNA. This is because DNA can be double stranded or single stranded while RNA is generally single stranded structure that can be double stranded only when it forms a hair pin like structure.
The features of hairpin structure in RNA are as follows:
1. This structure is a building block of many secondary structures of RNA.
2. The termination sequence during transcription also forms a hairpin loop like structure.
3. tRNA also forms a hairpin loop like structure and helps in the process of translation.
Explanation:
An amino acid is an organic molecule that is made up of a basic amino group (−NH2), an acidic carboxyl group (−COOH), and an organic R group (or side chain) that is unique to each amino acid.
