How should you attempt to avoid contamination of reagents?

Astructural difference between the trachea and esophagus that prevents the trachea from collapsing is the presence of: a) smooth muscle b) skeletal muscle c) respiratory cilia d) rings of cartilage

Mary has spontaneously decide to make a meal for friends. she is beginning to prepare fin fish and realizes she wants to also prepare a hearty dish ready to serve at the same time. what should she prepare? a: rice which take 20 minutes b: past which takes 15 minutesc: baked potatoes, which take 50 minutes.d: grilled garlic bread,which takes 5 minutes.e: boiled dumplings,which takes 17 minutes.

What is the main structural difference between enveloped and nonenveloped viruses? a) enveloped viruses have their genetic material enclosed by a layer made only of protein.b) nonenveloped viruses have only a phospholipid membrane, while enveloped viruses have two membranes, the other one being a protein capsid.c) enveloped viruses have a phospholipid membrane outside their capsid, whereas nonenveloped viruses do not have a phospholipid membrane.d) both types of viruses have a capsid and phospholipid membrane; but in the nonenveloped virus the genetic material is between these two membranes, while in the enveloped virus the genetic material is inside both membranes.