PLEASE HELP ME ON BOTH QUESTIONS ASAP No links please

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

The sketch shows a rynchosaur, an extinct animal that is known only from fossils. there has been much debate about the classification of these creatures. some scientists suggest that they belong with primitive amphibians, and some think they are related to snakes and lizards. the data equally support both cases. which statement best explains how to draw a cladogram that includes the rynchosaur? draw the cladogram for amphibians. draw the cladogram for reptiles. draw two cladograms, both showing the traits, and leave it as a hypothesis. draw two cladograms, both showing the traits, and have scientists vote

Climate warming trends allow plant and insect species to inhabit larger ranges. select the best answer from the choices provided