The first members of classes Osteichthyes and Chondrichthyes appeared in the __________ period
a. Permian
b. Paleozoic
c. Devonian
d. Jurassic
e. Cretaceous
C
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Enveloped viruses ____
a. generally lyse host cells as they are released b. synthesize envelope lipids as they replicate within the host cell c. acquire their envelope as they bud from the host cell d. acquire their envelope as they enter the host cell e. always contain DNA genomes
Cells of bone tissue
What will be an ideal response?
The actin filament system is present in the nucleus
a. true b. false
In the form of gene therapy used successfully for severe combined immunodeficiency syndrome (SCID)-X1, the genetic engineering of human cells is done by _____
A) injecting engineered viruses into the patient's bloodstream B) injecting engineered viruses into the patient's bone marrow C) treating a relative's cultured bone marrow cells with genetically engineered viruses and then injecting these cells into the patient's bone marrow D) isolating the patient's bone marrow cells, infecting them with genetically engineered viruses, and injecting them back into the patient's bone marrow