Plz help, I need it by tomorrow

Why is it important to reduce the number of chromosomes in half when forming gametes for sexual reproduction?

2. given that most biochemical (other than coal) rocks react with hydrochloric acid, what does that tell you about organisms?

Which statements describe resources? one of the factors people use when deciding where they will live is the availability of resources. renewable resources have little value for people. resources are unevenly distributed throughout the world. energy is the world resource which has the highest use. the use of nonrenewable resources has decreased in recent history. the use of resources is evenly distributed throughout the world. the world's oil supply will last for the next forty years if its use continues as expected.