Which of the following cell types are used in phloem?
A. Vessel elements-short, wide cells
B. Sieve-tube members-alive at maturity
C. Tracheids-hollow, tube like cells
D. Lignin-cells dead at maturity

What is a codon and where is it found

When a human or animal consumes food, the carbon in that food is most likely to be converted into which of the following elements? a. carbon remains carbon b. nitrogen c. oxygen d. hydrogen

Which statement describes a way in which the digestive and excretory systems work together? a. the nephrons absorb nutrients from food going to the large intestine. b. the excretory system balances blood gases in the small intestine. c. the intestinal villi filter blood and send wastes to the bladder. d. the excretory system balances the salts and water obtained from digested food