Exploring DNA Terminology: Alleles, Genotypes, and Phenotypes

This video continues the discussion on DNA, focusing on genetic terms such as alleles, dominant and recessive traits, homozygous and heterozygous conditions, and the concepts of genotype and phenotype. It explains how genes, as DNA segments, code for proteins and determine traits. The video also covers how alleles represent different versions of a gene, and how dominant alleles are expressed over recessive ones. The differences between genotype (genetic makeup) and phenotype (observable traits) are also discussed, using examples of mice with different fur colors.

Which of the following terms refers to a segment of DNA that codes for a specific protein?

• Allele

• Phenotype

• Gene

• Genotype

What determines the characteristics that we develop?

• Diet

• Genes we inherit

• Environment

• Exercise

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What do we call different versions of the same gene?

• Proteins

• Genotypes

• Phenotypes

• Alleles

If an organism has two identical alleles for a gene, it is said to be:

• Heterozygous

• Homozygous

• Dominant

• Recessive

In a heterozygous organism, which allele is expressed?

• Both

• Recessive

• Neither

• Dominant

What color would a mouse be if it has one allele for purple fur (dominant) and one for green fur (recessive)?

• Green

• Purple

• Mixed

• Neither

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What is the term for the entire collection of alleles an organism has?

• Phenotype

• Genotype

• Allele

• Gene

Which term describes the physical characteristics that result from an organism's genetic code?

• Gene

• Phenotype

• Allele

• Genotype

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If two mice have the same phenotype but different genotypes, what can we infer?

• They have the same alleles

• They are the same genetically

• They look different

• They have different alleles

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Which of the following is true about a homozygous recessive mouse?

• It has no alleles

• It has two recessive alleles

• It has one dominant and one recessive allele

• It has two dominant alleles