Use the text below to answer part 1. Then use the link for parts 2-5
What color is your hair? Now, think about your classmates. Do you all have the same hair color? Traits, or characteristics like hair and eye color, are determined by genes, sections of information on DNA. Our DNA is like a master plan for our bodies, and genes are the individual instructions for building each piece.
For each trait, we inherit two copies of a gene: one from our mom and one from our dad. Each of these copies can be different, and these different copies of the same gene are called alleles.
Now think about eye color. One allele of the gene for eye color might have the instructions for making brown eyes, while another allele has the instructions for making blue eyes. So, which instructions will your body follow?
Imagine you had two teachers in your classroom (and let's hope they don't give double homework!). If one teacher was shouting 'Take out your math homework' and the other teacher was whispering 'Open your English book,' which instructions would you follow? Most people would probably pull out their math assignments because those instructions were louder.
Just like these teachers, some copies of a gene are louder than others. The instructions on these louder alleles are followed to make traits even when a copy of a quieter allele is around. These louder alleles that are expressed over others are called dominant. On the other hand, alleles that aren't expressed if a dominant allele is around are called recessive .
Genotype and phenotype are closely related as part of an organism's genetics. Genotype is the inner genetic information that determines the outward appearance, or phenotype.
Genotype is the genetic makeup of an organism. It is responsible for inherited genetic information. Each individual, except for identical twins, has their own genotype. Genotype is carried on two alleles in the cell, one from each parent, which can be the same or different. In sexual reproduction, the parents' genotypes contribute to the child's genetic makeup.
Phenotype is the observable traits of an organism that result from their genotype. Traits such as hair color or the ability to roll your tongue are part of an individual's phenotype. It includes characteristics such as size, shape, color, and behavior. Phenotype is affected by environment and can change over time.