Genetics vocabulary | Inheritance and variation | Middle school biology | Khan Academy

TL;DR

This video provides an overview of how genes are inherited, explaining the concepts of genotypes (the genetic makeup) and phenotypes (observable traits).

Transcript

• [Instructor] We know that any sexually reproducing organism is getting DNA from both its male parent and its female parent and that's true also for human beings. You might know we have 23 pairs of chromosomes but let's zoom in on one of those pairs. So let's say this is one of the chromosomes in a pair and let's say that this is the other chromos... Read More

Key Insights

• 👨‍💻 Chromosomes are composed of DNA and contain genes that code for different traits.
• ❓ Alleles are different versions of a gene and can be associated with the same trait.
• 💄 Genotype is the genetic makeup of an organism, determined by the alleles it possesses.
• 😑 Phenotype is the observable expression of a genotype and can be influenced by dominant and recessive alleles.
• 😑 Dominant alleles express themselves in the phenotype, while recessive alleles require two copies to be expressed.
• ❓ Homozygous genotypes have two of the same alleles, while heterozygous genotypes have different alleles.
• ❓ Genotypes and phenotypes are important concepts in the study of genetics.

Questions & Answers

Q: How do chromosomes relate to genes?

Chromosomes are made up of strands of DNA that contain segments called genes. Genes code for different traits.

Q: What are alleles?

Alleles are different versions of a gene. They can be associated with the same trait, such as hair color, but have slight variations.

Q: How do you determine an organism's genotype?

An organism's genotype is determined by identifying the specific alleles it possesses for a particular gene. Each parent contributes one allele.

Q: How does phenotype relate to genotype?

Phenotype refers to the observable traits of an organism, while genotype represents its genetic makeup. Phenotype is influenced by dominant and recessive alleles.

Summary & Key Takeaways

• Chromosomes are strands of DNA that contain genes, which code for different traits.

• Alleles are different versions of a gene, and an organism's genotype refers to the specific alleles it possesses.

• Phenotype is the observable expression of a genotype, and can be influenced by dominant and recessive alleles.