Answer:
Immune system of the body helps in fighting with the infectious agents that are foreign for the body. So the immune system protects us from infection.
When any foreign substance(antigen) comes in the body B-lymphocyte recognize it by binding the antigen through its receptor. After recognizing the antigen, B cell divides into antibody-producing plasma cell and memory cell.
Antibodies produced by plasma cells help in destroying the antigen by getting the antigen recognized by phagocytic cells or by complement activation.
B cells are antigen-presenting cell which present antigen to T cell and then T cell activates and produce chemicals that kill the antigen. Therefore the immune system has many immune cells that activate when an antigen comes in the body. This is how the immune system functions.
Answer:
The three genes in coupling are in repulsion.
Explanation:
Coupling happens when the dominant alleles and the recessive alleles are on the same homologous chromosome, while the repulsion happens when one chromosome has one dominant allele and one recessive allele and another homologous chromosome also has dominant and recessive alleles.
If the progeny has:
nb+ ls+ a/nb ls a ⇒ nb+ ls+ a
nb ls a+/nb ls a ⇒ nb ls a+
Where nb+ ls+ a is the dominant alleles and nb and nb+ is in middle.
ls+ nb+ are on the same chromosome (both dominant)
ls nb are on the same chromosome (both recessive)
ls nb, these two are in coupling with each other, but ls+ and a are on the chromosome and ls+ or nb+ are dominant, while nb+ and a are recessive on form a, thus, ls and nb, they are in repulsion with a.
Answer:
Vertebrates are further classified according to several criteria like exoskeleton, respiratory organs, method of giving birth, number of chambers in heart, mode of living etc. They are further classified into classes Pisces, Amphibia, Reptilia, Aves and Mammals
The gasoline engine where the air and fuel mixture is burned is called the combustion chamber. A piston is used to increase and decrease the volume which prepares the fuel to be mixed with air. A spark plug is ignited then to create the combustion thereafter.
