Which geological era is known as the age of reptiles?

a. Cenozoic

b. Mesozoic

c. Paleozoic

d. Precambrian

How are complementary strands of DNA held together? A) with hydrogen bonds connecting complementary bases B) with phosphodiester bonds connecting sugars and phosphate groups C) with hydrogen bonds connecting complementary sugars D) with ionic bonds

Which of the following was in the 1940s to analyze amino acids that make up proteins? genetic engineering chromatography radioactive tracers x-ray diffraction

Which of these rules does not apply to the first week on the job?

An ecosystem with wet soil, willow trees, and orchids is likely a. a marsh. c. a forest. b. a swamp. d. a pond.

Although having evolved independently, the tracheal tubes of mammals and insects are both supported by rigid tissues. the trachea of a mammal is supported by cartilage, and the tracheae of an insect are supported by chitin.

Which of the following tools should a scientist use to measure an object in meters? Electronic balance Pan balance Tape measure Thermometer

What causes nematocysts to discharge?

Why are biologists concerned about the destruction of rainforests?

Mitosis produces which cell type? O haploid O diploid O chromosome gamete

Jason is in middle school and is well below normal height for his age. which hormone might be in short supply in jason's body?