Scientists are often faced with ethical questions, or questions of right and wrong. Which of the following are examples? I. Mairead wants to include a hypothesis in her report, and she asks if she must give credit to the scientist who first proposed it.
II. Aiden is planning an experiment on gerbils, and he asks how large the cages should be.
III. Paula is developing a new technique for mining fossil fuels, and she asks if the technique must avoid polluting the environment.

the core of the sun is so hot and there is so much pressure, nuclear fusion takes place, hydrogen is changed to helium. nuclear fusion creates heat and photons. when the heat reaches the earth it warms the molecules of the atmosphere, and they warm other molecules and so on.

"do a testcross with a homozygous recessive plant."

the offspring would all be white. if the parents are both white flowers then they have the genotype rr, which when crossed results in an all white punnet square.