In the first step of spermatogenesis, spermatogonia differentiate cells into
a. spermatids
b. primary spermatocytes
c. secondary spermatocytes
d. spermatozoa
e. spermatophyte

Which phrase is the best summary of the model shown? a. the transfer of the sun's energy through trophic levels b. a series of aerobic and anaerobic reactions c. a transformation of light energy into chemical energy d. the breakdown of food molecules

Did you know that a blue wales tongue weighs more than an elephant?

Group control group #1 experimental group yes yes yes control group #2 no new drug orange juice bed rest no yes no yes ves which of the following is the best explanation of why a second control group was included in this experiment? o a. to provide the volunteers in the study with something to drink o b. to prove that the common cold cannot be cured c. to confuse anyone who is trying to steal their new drug and sell it as their own invention o d. to researchers conclude that results are related to the new drug and not to the orange juice submit e previous