Why does it make sense for scientists to test just one variable at a time in an expirement?

Duchenne muscular dystrophy is sex-linked and usually affects only males. Victims of the disease become progressively weaker, starting early in life. a.

Severe weather that has caused deaths includes

A freshwater algal bloom has occurred in a farm pond due to water runoff from the surrounding fertilized fields. Which of the following options best describes this situation?

The role of a watershed is to ... a) purify water b) act as a drainage area c) collect fish from rivers and streams d) protect wetland areas

Snuppy, a male Afghan hound, was created by transferring the nucleus from an ear cell of the male Afghan, Tai, into an enucleated egg from a donor. The embryo was transplanted into a surrogate mother to develop to term.

Why when you rub a balloon on a piece of fabric or carpeting and then hold it against your head, your hair can stand up?

Which of the following statements is not true? Essential nutrients can be synthesized by the body. Vitamins are required in small quantities for bodily function.

Trees have active transport, why?

The question is how many chromosomes are in the sperm cells, and how many chromosomes will it's zygote have.

Recent research has found that on one island of the Galapagos two finch species interbred. This interbreeding may have resulted in a hybrid species that ultimately led to the extinction of one of the species Darwin discovered.