Which of the following statements is correct in describing the terms monohybrid cross and dihybrid cross? a) a monohybrid cross is performed for one generation, whereas a dihybrid cross is performed for two generations. b) a monohybrid cross results in a 9: 3: 3: 1 ratio, whereas a dihybrid cross gives a 3: 1 ratio. c) a monohybrid cross involves a single parent, whereas a dihybrid cross involves two parents. d) a dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied.

D) A dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied.

Explanation:

When you say monohybrid, this means that the organisms are heterozygous for 1 trait only. Dihybrid means that the organisms are heterozygous for 2 traits. This alone would make D correct.

You can perform both in one generation so you can take A out of the list.

A monohybrid cross would result in a 2x2 Punnett, so the results would be 3:1 and in a dihybrid cross, the Punnet is a 4 x 4 so the results would be 9:3:3:1. Since option B, is interchanged, then you can cross that out.

As or C, a monohybrid and dihybrid refers to the traits, not the number of parents.

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.

chert is a sedimentary rock composed of microcrystalline or cryptocrystalline silica. with this little bit of information, you can come to the conclusion that your answer is c.  

explanation: