The genetic material of all living organisms is ____
a. protein
b. deoxyribonucleic acid
c. ribonucleic acid
d. glycoprotein
e. polypeptide
ANSWER: b
You might also like to view...
Identify the signals necessary for maturation and activation of a B cell by a T-dependent antigen.
A. Antigen is internalized and presented by a dendritic cell. B. B-cell growth factors secreted by TH2 cells mature and activate the antigen-stimulated B cell. C. Antigen binds to a B-cell receptor. D. B cell secretes cytokines to activate a T helper cell.
Some transcriptional repressors work by ____
a. binding to the same sequence where activators normally bind b. binding to and disabling the activator c. recruiting histone acetylation enzymes and thus interfering with chromatin remodeling d. binding to RNA polymerase II and preventing it from binding to the transcription factor complex e. methylating DNA
Lungs absorb oxygen from inhaled air, and the small intestine move ingested material through the
digestive tract and absorbs nutrients from ingested food. Which of the following statements describes the type of epithelium you would expect to line each of these surfaces? a. They are both lined by a simple squamous epithelium. b. They are both lined by a simple cuboidal epithelium. c. The lungs are lined by a simple squamous epithelium, and the small intestine is lined by a ciliated columnar epithelium. d. The lungs are lined by a columnar epithelium, and the small intestine is lined by a simple squamous epithelium. e. The lungs are lined by a simple squamous epithelium, and the small intestine is lined by a simple cuboidal epithelium.
Which of the following bacterial genera includes species that protect areas of the body such as the intestinal tract and the vagina from invasion by pathogens?
A. Staphylococcus B. Listeria C. Lactobacillus D. Mycobacterium E. Corynebacterium