Which of the following is a disadvantage of a correlational experiment?
A) Subjects may not know exposure levels.
B) It is expensive and time consuming.
C) It is not feasible for rare diseases or environmental factors of interest.
D) It is only feasible for hypotheses for which an experimental treatment can be applied.
D
You might also like to view...
Which of the following is a similarity between photosynthesis and respiration?
a. Neither is a metabolic process. b. They are both metabolic processes. c. Neither is an anabolic process. d. They are both mainly anabolic processes.
Amniocentesis and chorionic villus sampling allow for ________ and ________ of the fetus so that it can be tested for abnormalities
A) imaging; karyotyping B) sexing; imaging C) karyotyping; biochemical testing D) direct observation; biochemical testing
Based on the table of average intron frequency given below, predict the relative order of genome size for these four eukaryotic organisms
Organism Average Intron Frequency Cryptosporidium parvum 0 Plasmodium falciparum 1 Arabidopsis thaliana 5 Homo sapiens 8 A) Homo sapiens > Arabidopsis thaliana > Plasmodium falciparum > Cryptosporidium parvum B) Cryptosporidium parvum > Plasmodium falciparum > Arabidopsis thaliana > Homo sapiens C) Homo sapiens > Cryptosporidium parvum > Plasmodium falciparum > Arabidopsis thaliana D) Intron frequency cannot be used to predict genome size in eukaryotes.
Clostridium difficile is inoculated to two different media. Media X is a rich, nutritious complex growth media. Media Y is a minimal synthetic media containing only the minimum ingredients needed for growth. After 48 hours, which media do you expect to contain a greater proportion of endospores? Explain your reasoning.
b. What is the counterstain used in acid-fast staining? c. Why can safranin not be used as the counterstain in acid-fast staining? d. In your own words, explain why some bacterial species produce endospores. What are their purpose? e. Name two genera of bacteria that produce endospores. f. What is the primary stain in Schaeffer-Fulton endospore staining? g. What is the counterstain in Schaeffer-Fulton endospore staining? h. What is the purpose of steam during Schaeffer-Fulton endospore staining? What do you expect would happen if steam were not used?