(30 points!) What is the relationship among DNA, a gene, and a chromosome?
A chromosome contains hundreds of genes, which are composed of DNA.

A chromosome contains hundreds of genes, which are composed of protein.

A gene contains hundreds of chromosomes, which are composed of protein.

A gene is composed of DNA, but it has no relationship to a chromosome.
A gene contains hundreds of chromosomes, which are composed of DNA.

Imagine ? person stepping on a pin and pulling his or her foot way look at the réfléchir arc of the scenarios below

Explain two reasons you think it is important for scientists to search for new ways to treat cancer

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.