Down's Syndrome is also called Trisomy 21 because affected people have three copies of chromosome 21. How is this possible?

This is one form of rna that transports a specific amino acid to a ribosome during protein synthesis.

An ecologist is studying the effects that a population of predators is having on a population of a prey. he used data from the field to produce this graph. which conclusion can draw from the graph?

Neelaredoxin is a 15-kda protein that is a gene product common in anaerobic prokaryotes. it has superoxide-scavenging activity, and it is constitutively expressed. in addition, its expression is not further induced during its exposure to o2 or h2o2 (silva, g., et al. 2001. j. bacteriol. 183: 4413–4420). which of the following statements best describes neelaredoxin synthesis? a-neelaredoxin is produced at all times; levels are constant even when exposed to o2 or h2o2.b-neelaredoxin is produced at all times; exposure to o2 or h2o2 increases expression.c-neelaredoxin is produced at all times; exposure to o2 or h2o2 decreases or prevents expression.d-neelaredoxin is only produced when there is exposure to o2 or h2o2.