Consider the validity of the following statements about genome editing. Select True or False for each statement.T/FCas proteins work as endonucleases.T/FsgRNA is used by bacterial cells to detect which DNA to cut.T/FHomologous recombination is always used to join pieces of broken DNA.T/FIt is possible to modify genes as well as disrupt them by genome editing.

A tool-kit gene is .

DRAW IT Below are the amino acid sequences (using the single-letter code; see Figure 5.14) of four short segments of the FOXP2 protein from six species: chimpanzee (C), orangutan (O), gorilla (G), rhesus macaque (R), mouse (M), and human (H). These segments contain all of the amino acid differences between the FOXP2 proteins of these species.

Use a highlighter to color any amino acid that varies among the species.

Explain how RNA-seq can be used to analyze patterns of gene expression.

What would researchers have to demonstrate to convince you that they had discovered life on another planet?

Gene density is the number of genes per million base pairs (Mbp). Using Figure 20.5b, find the approximate number of genes estimated in water fleas and in humans, and note the size of each genome. Calculate the gene density in water fleas relative to that in humans.

What is left for genetic researchers to do now that the Human Genome Project has determined nearly complete nucleotide sequences for all of the human chromosomes? Explain.

Once an organism's genome sequence has been determined, how do scientists generally start identifying all the genes within the genome?

What tool or resource is useful for identifying previously unknown protein-coding genes in a genomic DNA sequence?