NEET Biology Genetics : Cis and Trans Linkage

TL;DR

CIS linkage refers to when both dominant alleles of a gene pair are located on the same chromosome, while trans linkage occurs when one dominant allele and one recessive allele are on the same chromosome.

Transcript

Hello friends this video on need genetics is brought to you by exam.com no more fear from exam now when we talk about linkage there are two types of linkage Arrangements which are possible so the first is CIS type Arrangement or CIS linkage and the second one is trans linkage so let's first talk about CIS linkage so let's so in CIS linkage dominant... Read More

Key Insights

• 🏃 CIS linkage occurs when both dominant alleles of a gene pair are on the same chromosome of the homologous pair.
• ⚧️ Trans linkage happens when one dominant allele and one recessive allele of a gene pair are on the same chromosome of the homologous pair.
• 😚 Linked genes are located close to each other on the chromosome and are more closely linked if they are closer together.
• 👪 Homologous chromosomes are paired chromosomes received from each parent.

Questions & Answers

Q: What is CIS linkage?

CIS linkage occurs when both dominant alleles of two gene pairs are located on the same chromosome of the homologous pair. This type of arrangement is denoted as capital A capital B / small a small B, where the capital A and capital B alleles are on the same chromosome.

Q: What is trans linkage?

Trans linkage is when one dominant allele and one recessive allele of two gene pairs are located on the same chromosome of the homologous pair. It is denoted as capital A small b / small a capital B, with the capital A allele and small B allele on the same chromosome.

Q: How are linked genes arranged on the chromosome?

Linked genes are located close to each other on the chromosome. The closer they are, the more linked they are. This proximity allows for the possibility of both genes being located on the same chromosome.

Q: What are homologous chromosomes?

Homologous chromosomes are paired chromosomes. One chromosome in the pair is received from the mother, while the other is received from the father. These pairs of chromosomes make up the homologous chromosome set.

Summary & Key Takeaways

• CIS linkage is when the dominant alleles of two gene pairs are located on the same chromosome, while trans linkage is when one dominant allele and one recessive allele are on the same chromosome.

• Linked genes are located close to each other on the chromosome.

• Homologous chromosomes are paired chromosomes, with one received from each parent.