Which of the following has caused 100,00 year cycles of ice ages in the past?

A. An increase in sun spots

B. Several major volcanic eruptions

C. changes in earths orbit and the tilt of its axis

D. continental drift

If a single DNA strand contains 40 adenines prior to replication, what conclusion can be made about its complementary strand after replication, assuming no mutations occurred?

Why do conservationists sometimes purposely set a forest fire?

what kind of plant cells make up nut shells and seed coats

Risk of using bio pharmaceuticals

Where in the respiratory tract does gas exchange occur?

Interference occurs when: A. two genes are far apart on a genetic map. B. a crossover causes the termination of the meiosis event in which the crossover is occurring. C.

Which of the following statements about the germ layers is NOT correct? - The germ layers (ectoderm, mesoderm, and endoderm) arise from the embryonic disk. - The endoderm gives rise to the nervous system.

Why are the oceans becoming acidic? A) Because of global cooling B) Because of excess carbon dioxide in the atmosphere reacting with water and forming carbonic acid C) Because of the dissolution corals (calcium carbonate) D) Because of alkaline rain

What is the possible genotype and phenotype for the dominant trait circular flower and recessive trait square flower

What is representative organism?