All of the following were likely present on the early Earth during the evolution of self-replicating molecules except

amino acids

nucleotides

lipids

free oxygen

What are trans fats? Why are they bad?

Identify a specific example where the cell wall structure has aided the survival of a plant in its natural habitat.

What type of mutation results when bases are added to a gene A. frameshift B. Nondisjunction C. silent D. missense

Decide whether each statement about hormones is true or false. TrueFalse Homeostasis is regulated by two systems; the nervous system and the endocrine system. TrueFalse Hormones released by the endocrine system are secreted through ducts.

Juliet just ran a 100-meter race. She's experiencing severe pain in her leg muscles. What is the probable reason for this?

Which describes the habitat of a frog?

The size of a population refers to the

An electric current will always follow a. the path of least resistance. b. a path toward the north pole. c. a path toward the south pole. d. the path that leads through insulators.

What are some questions that biologists might ask about the living things they study?

A volcanic eruption causes melting of glaciers. Which of these Earth systems interact during this event? A atmosphere and biosphere B atmosphere and hydrosphere C geosphere and cryosphere D geosphere and biosphere