Cooing and babbling are early stages of speech development. As babies get older (often around 9 months), they begin to string sounds together, incorporate the different tones of speech, and say words like mama and dada (without really understanding what those words mean).
The map distance between two genes, measured in centimorgans or map units, equals the percentage recombination frequency between the two genes--the likelihood of offspring with copies of those genes on the same chromosome that come from different parents.ave. dna image by Allyson Ricketts from Fotolia.com. The concept of map distance in a genotype refers to where genes are located on a chromosome but does not refer to physical distance; rather, map distance refers to the tendency for a crossover to occur between genes.
A genome map describes the order of genes or other markers and the spacing between them on each chromosome. Human genome maps are constructed on several different scales or levels of resolution.At the coarsest resolution are genetic linkage maps, which depict the relative chromosomal locations of DNA markers (genes and other identifiable DNA sequences) by their patterns of inheritance.hromosome walking is also used to locate specific genes by sequencing the chromosomal segments between markers that flank t he gene of interest (Fig. 13). The current human genetic map has about 1000 markers, or 1 marker spaced every 3_million bp; an estimated 100 genes lie between each pair of markers.