4. using your knowledge of punnett squares and hybridization, what is the probability that apurebred monohybrid, dihybrid, three-factor cross or higher will lead to the expression ofdominant phenotypes in first-generation offspring? 5. why is it impossible to predict which of his or her two alleles each parent contributes for agiven gene? 6. as you've learned, thalidomide is a teratogen, meaning that it causes birth defects whentaken by pregnant women. another teratogenic compound is alcohol, which is known to causebirth defects in the developing child's nervous system and contribute to the development offetal alcohol syndrome. can you explain the function of teratogens such as thalidomide andalcohol in terms of environmental factors that play a role in organismal development? whatdoes the presence of teratogens mean for pregnant women who wish to have a healthypregnancy for both themselves and their future children? 7. some animals that look like they exhibit codominance actually do not. for example, thezebra, famous for its black and white stripes, obtains its pattern from a series of genes thatinitiate the production of a dark pigment called melanin on specific parts of its body. differentzebras can have different patterns of stripes as dictated by their genetic code. for example, the plains zebra has wide stripes, while the grevy's zebra has narrow stripes. what are someother examples of striped and spotted animals that are genetically encoded to have thesedesigns? 8. the fact that the zebra's stripes are passed down in its dna indicates that the stripes may serve an evolutionary advantage. what do you think is the evolutionary need for such complex designs?