Suppose it were possible to conduct sophisticated microscopic and chemical analyses of microfossils found in 3.5-billion-year-old stromatolites. which of the following structures would be surprising to observe?
i. rna
ii. vesicles
iii. a nucleus

Cells control gene expression at which steps

Mr. j, age 42, is a construction worker in las vegas. he recently noticed that a mole on his face seemed to be getting larger and darker. at first he did not worry because he was in the sun a lot and assumed the change may have been caused by sunburn. after a month, not only was the mole larger and darker, but it appeared to be “bumpy.” his doctor diagnosed a malignant melanoma skin cancer following biopsy of the nevus. mr. j reports pain in his right shin that does not go away when he puts his feet up or sleeps. discussion questions 1. relate mr. j’s skin changes to the warning signs for malignant melanoma. (see malignant melanoma.) 2. discuss the normal progression of this malignancy. what is the significance of the bone pain that mr. j is experiencing? (see malignant melanoma.) 3. discuss the treatment available for this patient and the prognosis for recovery. (see malignant melanoma.)

Which of the following statements about genes and traits is true? a single trait can be controlled by multiple genes. a single gene can control a single trait. a single trait can alter multiple genes. a single gene can influence multiple traits.