Number 8 is the question I need to know

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.

Earths energy sources include both renewable and nonrenewable resources. name at least three sources of energy that could be used in your house. then describe the ideal energy source for generating most of your homes electricity, and explain why you chose that source. can someone give me some ideas, i’m kinda confused.

If there is another new infectious disease somewhere in the world, what do you think canadian officials should do