Explain the phenomenon of incomplete dominance in sickle cell inheritance
What will be an ideal response?
Answer: Incomplete dominance occurs when there is a dominant-recessive pair of genes and the phenotype is affected mostly by the dominant gene, but the recessive gene also becomes expressed partially. In sickle cell anemia, a person inherits two recessive genes for the sickle-cell trait and their blood cells are disk-shaped rather than round, causing clogging and a number of problems, such as pain. If the person only inherits one recessive gene for the sickle cell trait, they will not have sickle cell anemia, but some of their blood cells will be misshaped. This condition causes resistance to malaria, an often fatal disease that is common in Africa. It would be adaptive to carry this recessive trait in Africa, so this explains the higher prevalence of sickle-cell diseases among people of African heritage.
You might also like to view...
By comparing reaction times across different tasks, Donders was able to conclude how long the mind needs to perform a certain cognitive task. Donders interpreted the difference in reaction time between the simple and choice conditions of his experiment as indicating how long it took to
A. perceive the stimulus. B. process the stimulus. C. attend to the stimulus. D. make a decision about the stimulus.
Which strategy is probably the MOST effective way to deal with stress across one's life span?
A) maintaining a highly emotional state of mind B) having an alcoholic drink or two per day C) displacing anger by reacting with rage towards inanimate objects D) having social support through family or friends
If you are helping a person relearn how to walk after a stroke, you begin by reinforcing the person for being able to stand with a walker, then taking a step, then taking another step, then moving the walker and taking another step and so on. You are using the behavioral procedure known as
a. reciprocal inhibition. b. shaping. c. stimulus control. d. classical conditioning.
As the Atlantic molly expert, you have been asked to predict a male Atlantic molly's mate selection when exposed to two females of different sizes, who have or have not been observed in the presence of other male Atlantic mollies
On the basis of a study described in the textbook, you should predict that the male Atlantic molly will choose the female a. that is larger. b. that has been left alone. c. that has been observed with another male. d. that is more active in the water.