True or false A hypotheses has been tested many times by different independent researchers but a theory has not

Which element provides strength to the exoskeleton of clams and oysters

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?

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