A well designed experiment does not contain the following. random assignment to study groups non-random assignment to study groups manipulate the independent variable Help me please l I need your help please

Suppose a scientist measures the amount of dna per cell of a particular diploid species at various stages of meiosis. she finds that the meiotic cells contain 3.7 pg , 7.3 pg , or 14.6 pg of dna. match each stage of the cell cycle to the corresponding amount of dna contained within a cell at that stage.

In german cockroaches, curved wing (cv) is recessive to normal wing (cv+). bill, who is raising cockroaches in his dorm room, finds that the frequency of the gene for curved wings in his cockroach population is 0.6. in his friend joe’s apartment, the frequency of the gene for curved wings is 0.2. one day joe visits bill in his dorm room, and several cockroaches jump out of joe’s hair and join the population in bill’s room. bill estimates that, now, 10% of the cockroaches in his dorm room are individual roaches that jumped out of joe’s hair. what is the new frequency of curved wings among cockroaches in bill’s room? 0.69 0.4 0.5 0.31 0.20

After getting the slide and microscope ready, stella is eager to see the microscopic pond water specimen! she crouches around her microscope and aligns her eye with the microscope’s eyepiece. but she's only able to see a bright white light. at this point, no specimens or cells are visible on stella's pond water slide. after taking a moment to collect her thoughts, stella realizes she can't see any lifeforms because .