How does the molecular clock work?

a. it analyzes the brain functionality of two different species.

b. it examines and compares the physical characteristics of two different species.

c. it illustrates relationships between two different species.

d. it compares the number of mutations that exist in the dna of two different species.

Which of the following is a macronutrient? carbohydrates lipids amino acids all of the above

The relationship between intron and exon

During crossing-over, a. genetic material is exchanged between nonsister chromatids, resulting in new combinations of alleles. b. nonsister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. c. one homologous chromosome of a tetrad is exchanged with another tetrad, resulting in new combinations of alleles. d. sister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. e. genetic material is exchanged between sister chromatids, resulting in new combinations of alleles.