Answer:
2. Human height is determined by several genes located on different chromosomes.
3. A person with AB blood type.
4. Hydrangea flower color varies with soil pH.
Explanation:
2. Polygenic ( poly- many) traits are the genetic traits that are governed by several genes. Human height is one such example. Other examples in humans are skin color, eye color, etc.
3. There are 3 alleles responsible for the blood type in humans, which are
- Ia- the dominant allele that produces Antigen A on the surface of RBC.
- Ib- the dominant allele that produces Antigen B on the surface of RBC.
- Io - the recessive allele that doesn't produce any antigen.
Thus, when both the alleles for A blood type and B blood type are present, both are expressed as A and B antigens on the surface of RBC because of Codominance (Co- together) thus producing AB blood type.
4. The pH of the soil is an environmental factor. Hence, the change of color based on the soil pH is an example of the environment affecting a genetic trait.
