Why are theories modified over time?

Nonvascular plants lack which of the following structures? true roots, chloroplasts, and stems true roots, phloem, and xylem. true roots, xylem, and cell walls true roots, cell membranes, and flowers

Sebaceous secretions associated with hair follicles that secrete an oily, odorous, messy secretion are due to what type of secretion mechanism?

Biology students used raw eggs in an experiment on tonicity and osmosis. The students put their eggs into vinegar to remove the shells. The vinegar was used to remove the shell form the raw egg.

Name an organism that acts as secondary consumer and a tertiary consumer.

All cells are dependent on what fuel for energy

Why are sharks so successful at what they do?

The nucleus of an atom is comprised of

When the double stranded DNA helix is unwound, two single strands of DNA are formed. These strands have to be stabilized because their hydrophobic bases are exposed to water. The proteins that stabilize the two single strands are called

If the fatty acid has two or more double bonds, they are always spaced at three carbon intervals ... explain.

What do you call the sections chromosomes are divided into?