What is the approximate minimum stream velocity required to transport the smallest particles of sand?

Which of the following statements is true of cells

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.

Dna in the nucleus carries the genetic code for making proteins in ribosomes. the diagram shows a model of dna. which part of the dna molecule codes for the amino acid sequence in the protein? a) sugar b) phosphate c) deoxyribosed) nitrogen bases