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Title: How can an individual carry a defective gene but not exhibit the defective phenotype? Post by: microlin on Sep 21, 2012 How can an individual carry a defective gene but not exhibit the defective phenotype?
a)An individual may not have that defective gene in every cell, and so appear normal b)Individuals carry two copies of gene instructions, and one dominant allele could mask the presence of a recessive defective allele c)Individuals are always homozygous d)Both a) and c) are true e)None of the above is true Title: How can an individual carry a defective gene but not exhibit the defective phenotype? Post by: rkearl27 on Sep 21, 2012 Content hidden
Title: How can an individual carry a defective gene but not exhibit the defective phenotype? Post by: rl127 on Sep 21, 2012 b) Individuals carry two copies of gene instructions, and one dominant allele could mask the presence of a recessive defective allele
Title: How can an individual carry a defective gene but not exhibit the defective phenotype? Post by: microbio24 on Sep 21, 2012 B
Title: How can an individual carry a defective gene but not exhibit the defective phenotype? Post by: Rkumar2577 on Sep 21, 2012 Lili,
The question is a poor one. For starters, it should say "an individual carry a defective allele"..... NOT a defective gene. Second, it is possible that an individual is a mosiac of functioning genes. For example, human females have, randomly, either one or the other X chromosome active.... the inactive X chromosome is the Barr body. Thus if there is a "defective" allele on one of the X chromosomes of a female, then.... "a" above is functionally correct. It's obvious the asker wants "b" as the answer..... but the question is really poor. |