How do scientists know when life began?

A researcher has found variation in courtship behavior among closely related species. She has determined that simple courtship dances are the ancestral form of the trait, while complex courtship dances are derived.

A condition where to bones becomes weak and breaks easily

What is the geologic time scale?

What is a example of asexual representation.

g We are interested in determining whether plumage for the Guinea hens follow a common epistatic relationship. The observed phenotypes are dull, bright and brilliant.

A woman is 20 weeks pregnant. the nurse would expect to palpate the fundus at which location?

Which is the correct sequence of increasing organization? a Organ, tissue, cell, molecule b Atom, molecule, tissue, cell c Organelle, tissue, cell, organ d Cell, tissue, organ, organ system e Molecule, cell, organelle, organ

You are excited because your lab is studying the first microorganisms retrieved from Mars! Interestingly, their genetic material consists of a single-stranded nucleic acid with six different nitrogenous bases.

Explain what air pressure indicates with weather

Plate tectonics is the theory that the Earth's crust is made up of plates that glide over a layer of mantle. A prediction of this theory is that the plates will move relative to each other as they move over the mantle.