Animals that possess homologous structures probably _____.
A) are headed for extinction
B) have a common ancestor
C) have increased genetic diversity
D) by chance had similar mutations in the past
E) are not related
Answer: B) have a common ancestor
You might also like to view...
Using the genetic code shown here, predict what type of mutation has occurred in the hemoglobin sickle-cell anemia allele.
Normal allele 5'–GGAAUGAAACAGGAACCC–3'
Mutant allele 5'–GGAAUGAAACAGGUACCC–3'
A. a point mutation, Val to Glu
B. addition of a new stop codon
C. a frameshift mutation
D. a point mutation, Glu to Val
E. a silent mutation
You are a famous endocrinologist and are presented with a case in which a genetically determined male (XY) exhibits secondary female characteristics, including breast development and lack of facial hair growth
What may you hypothesize about this patient? A) He may lack receptors for testosterone. B) He may have a tumor in his testes causing an overproduction of testosterone. C) He may be abusing steroids. D) He may actually be perfectly healthy and normal.
Membrane proteins are not very soluble in water, because they possess long stretches of non-polar amino acids that are
A. too long to interact with the water molecules. B. hydrophilic. C. hydrophobic. D. used as transport channels. E. are transmembranal.
A cell wall can increase a bacterium's virulence because cell wall lipid A
A) All bacteria have a cell wall and all are not pathogenic; therefore, cell walls do not contribute to virulence. B) Helps the bacterium attach. C) Resists phagocytosis. D) Destroys host tissues. E) is toxic