Genotypes and Phenotypes in Genetics

The video tutorial explains the concepts of genotypic and phenotypic ratios. It begins by defining genotype as the genetic makeup of an organism and phenotype as the physical traits. Using a Punnett square, the tutorial demonstrates how to calculate genotypic ratios by counting homozygous dominant, heterozygous, and homozygous recessive genotypes. It then explains phenotypic ratios by identifying the number of organisms displaying dominant and recessive traits, emphasizing the role of dominant alleles in determining phenotype.

What does the term 'genotype' refer to?

• The environment of an organism

• The diet of an organism

• The genetic makeup of an organism

• The physical appearance of an organism

Which of the following represents a homozygous dominant genotype?

• Bb

• bB

• BB

• bb

In a Punnett square, what does a genotypic ratio of 1:2:1 indicate?

• 1 homozygous dominant, 1 heterozygous, 2 homozygous recessive

• 1 homozygous dominant, 2 heterozygous, 1 homozygous recessive

• 1 heterozygous, 2 homozygous dominant, 1 homozygous recessive

• 1 homozygous recessive, 2 homozygous dominant, 1 heterozygous

What does a heterozygous genotype look like?

• bb

• BB

• bB

• Bb

What is the main difference between genotypic and phenotypic ratios?

• Genotypic ratio refers to physical traits, phenotypic ratio refers to genetic traits

• Genotypic ratio refers to genetic traits, phenotypic ratio refers to physical traits

• Phenotypic ratio is always larger than genotypic ratio

• Genotypic ratio is always larger than phenotypic ratio

Which of the following is a phenotype?

• bb

• BB

• Bb

• Brown fur

How many organisms show the dominant trait in the given example?

• Four

• Three

• Two

• One

What is the phenotypic ratio in the example provided?

• 1:3

• 3:1

• 2:2

• 1:1

Which genotype will show the recessive trait?

• bB

• Bb

• BB

• bb

What is required for an organism to display a recessive trait?

• One dominant allele

• Two recessive alleles

• Two dominant alleles

• One recessive allele