A man drinks swamp water and later contracts malaria. This fact alone does not provide conclusive evidence that swamp water is responsible for causing malaria. To draw a valid conclusion, a experiment with only one factor is needed.

(first blank choices: controlled, scientific or dual)
(second blank choices: constant, variable or common)

Hurry which of these is true about index fossils? a) are very scarcely found b) used as guides in relative dating c) found in the youngest layer of the rock d) used as reference points in absolute dating

Many birth-control pills release a constant amount of synthetic estradiols and progesterone for 21 days. true or false

Imagine you are a student in alfred hershey and martha chase's lab in the late 1940's. you are given five test tubes with the e. coli bacteria that were infected with t2 bacteriophage that have been labeled with 32p or 35s. unfortunately, you forgot to label the tubes and are now uncertain which were 32p labeled and which were 35s labeled. you place the contents of each tube in a blender and pulse it for a few seconds to shear off the protein coats from the bacterial outer membranes. you then centrifuge the contents to seperate the protein coats and the bacterial cells. you then check for radioactivity and obtain the results shown below. which tubes contained e. coli infected with the phage labeled with 32p? select all tubes that apply.