Microsoft Word – Exam V Practice Questions.docx
- Human skin cells and human white blood cells of the immune system both perform protective functions. Skin cells function primarily in external physical protection, whereas white blood cells function primarily in internal protection. Nonetheless, both types of cells contain a complete copy of the human genome. Explain how cells can have the same genetic information and yet perform different functions. What prevents skin cells from making all the same proteins of a white blood cell?
- At several points in the cell cycle there are checkpoints that control the cell’s passage from one phase to the next. If a cell receives a signal at each checkpoint, it continues to the next phase; if it does not receive the signal, the cell does not continue. For example, a growth factor may stimulate a cell to move from G1 into S phase. If no growth factor is present, the cell cycle stops in G1 and the cell does not divide. Predict what would happen to a cell and to a multicellular organism if there was a defect at the checkpoint and the cell continued through the cell cycle even in the absence of a signal.
- Meiosis and sexual reproduction allow for highly unique offspring. What are the three sources of genetic variation in either meiosis or sexual reproduction (what is the source, when/where does it occur)?
- Identify and explain two advantages of sexual reproduction over asexual reproduction.
- Cystic fibrosis (CF) is a disease caused by a recessive allele, and the disease appears only in the homozygous recessive genotype. Two parents do not have cystic fibrosis, but they produce a child with this disorder. Fully explain what has occurred, using the appropriate terminology and diagram (you must provide this diagram).
- The inheritance of curly hair illustrates incomplete dominance. When a curly haired individual reproduces with a straight-haired one, the children all have wavy hair. What offspring would be produced, in what proportions, when two people with wavy hair reproduce?
- A man with type O blood has a sister with type AB blood. What are the genotypes and phenotypes of their parents?
- Using a pedigree, how can you tell if a trait is autosomal or sex-linked (X-linked)? Dominant or recessive?