Bone marrow, thymus, spleen and tonsils are organs of the what system

Biological evolution that occurs by chance or a random event is called

What best describes a gene

A student travels to Brazil by boat on the Amazon River, without visiting the doctor prior to traveling for recommended vaccinations for travel to South America. The student becomes ill during the trip and is quarantined.

Which statement is a testable scientific hypothesis

A dish of animal cells was grown in the presence of radioactive phosphorous. The phosphorous largely ended up in nucleotides inside the actively growing animal cells.

Why is the resting membrane potential (Vm) approximately - 70 mV for most cells? Most cells contain a large concentration of Cl - making them negatively charged.

Variations in elevation of a land surface is

Imagine that you travel back in time 600 million years and are looking at marine organisms. What types of skeletons would you observe in these creatures?

Does iodine turn yellow or black when starch is present in a solution?

During this phase of Mitosis, the spindle fibers shorten and pull apart the sister chromatids to opposite poles of the cell: cytokinesis Anaphase Prophase Metaphase