What is a gene? a single strand of DNA. the fundamental unit of heredity. a single nucleotide. the fundamental unit of DNA

the fundamental unit of heredity

Explanation:

DNA is a double stranded helix structure. Each strand is made up of a string of nucleotides.

A gene is a region of DNA, usually tens of thousands of nucleotides long. At the simplest level, one gene encodes for one trait. Therefore, the gene can be described as the fundamental unit of heredity.

Genes work by coding for specific proteins, which carry out essentially all the functions in the cell.

this protocol describes a detailed procedure for intracellular flow cytometry staining.

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.