Scientists believe that the direction birds go when migrating is guided in part by i) the stars in the night sky ii) the sun during the day iii) the magnetic field of the earth

Explain the source of radioactivity in uranium in earth’s crust by which it produces nuclear radiation

Organelles found in plant cells that function through photosynthesis to produce glucose from carbon dioxide and water are called — question 21 options: chloroplasts guard cells photosynthons

Which of the following is the best definition of a eukaryota? a. a one-celled organism that does not have a membrane-bound nucleus b. a one-celled organism that does not have a cell wall c. an organism whose cells each contain a membrane-bound nucleus d. an organism whose cells each have a cell wall