Explain why a lead kept in the light for 24 hours will turn an iodine solution blue-black, whereas a lead kept in the light for 24 hours and then in the dark for 24 hours will have no effect on an iodine solution. (4Marks)

Scientist have long study the earths climate by looking at which of the following? the earths orbit. the earths rock layers. the antarctic ice. the earths oceans.

Which of the following is the main purpose of a human community?

Which statement is not an accurate description of meiosis? a) meiosis produces offspring that are genetically diverse. b) meiosis produces offspring that are identical to the parent. c) in sexual reproduction half of the genetic material comes from the father (sperm) and half of the genetic material comes from the mother (egg). d) meiosis decreases the number of chromosomes by half so that when a sperm fertilizes an egg, the resulting zygote has the correct number of chromosomes.