Content Writer
Recombination is a process by which molecules of DNA are broken down into smaller molecules and recombined to produce new combinations of alleles.
- It takes place when paternal and maternal are regrouped in the formation of gametes.
- The process of recombination is carried out with the help of meiosis.
- Meiosis helps in the process of cell division, which results in the formation of eggs or sperm.
- Recombination is responsible for ensuring that no daughter cells are identical.
- It also ensures that no identical genetic content is attached to the parent cell.
- The body of a human is made of 46 chromosomes, which is equivalent to 23 pairs of genes.
Read More: How do Organisms Reproduce?
| Table of Content |
Key Terms: Recombination, Meiosis, Cell Division, DNA, Genes, Offspring, Chromosomes, Crossover
Types of Recombination
[Click Here for Sample Questions]
Recombination is defined as the process of breaking and recombining strangants of DNA to form new alleles. It is divided into four broad categories:
Homologous Recombination
Homologous Recombination is a type of recombination that takes place between DNA molecules of similar sequence. This type of chromosome takes place in diploid organisms. It is also known as general recombination.
Non-Homologous Recombination
Non-Homologous Recombination is a type of recombination that takes place between DNA molecules of different sequences. It is also known as Illegitimate Recombination. The most common example of non-homologous recombination is translocations between different chromosomes.
Site Specific Recombination
The third category of recombination is site specific recombination. This recombination is carried out in dissimilar parental molecules of short sequences. The most common example of site specific recombination is integration of bacteriophage.
Mitotic Recombination
The last category of recombination is mitotic recombination. This process is carried out during interphase when a new copy of DNA. This category of recombination is quite harmful as it can lead to tumours.
Read More: Reproductive Health
Process of Recombination
[Click Here for Previous Year Questions]
The process of recombination is carried out with the help of meiosis, as it helps in the generation of gametes.
- In the first step, maternal and paternal DNA are aligned in one phase.
- Next, the arms of chromosomes are made to overlap and fuse with each other, causing crossover.
- Crossover helps in the exchange of genetic material between maternal and paternal DNA.
- Genes of the same DNA fragments are more likely to recombine.
- This in result will increase the frequency of recombination.
Read More: Packaging of DNA
Examples of Recombination
[Click Here for Sample Questions]
The concept of recombination is explained with the help of two chromosomes A and B in which one chromosome acts as a wild allele and the other chromosome acts as a mutant allele.
- Recombination takes place between genes A and B in which they exchange wild allele chromosomes with mutant allele chromosomes.
- The process of breaking and rejoining chromosomes takes place with the help of meiosis.
- The DNA from top of the chromosome is removed and added to the bottom of chromosome.
- This results in the formation of new genes from two parental genes.
Read More:
Things to Remember
- Recombination is the process of physical breakage, exchange and rejoining of genetic molecules of DNA.
- The process takes place when maternal and paternal genes are aligned in one phase.
- The chromosomes are found in the nucleus of the cells which are in the shape of genes.
- They are divided into four broad categories namely Homologous Recombination, Non-Homologous Recombination, site specific recombination and mitotic recombination.
- The process of recombination is carried out with the help of meiosis.
- Recombination takes place in humans, animals and plants.
Previous Year Questions
- Extraction of metal from the ore cassiterite involves...[JEE Advanced 2011]
- Commonly used vectors for human genome sequencing are...[NEET UG 2014]
- Interfascicular cambium and cork cambium are formed due to..
- Pneumotaxic centre is present in...[UP CPMT 2007]
- Reaction of HBr with propene in the presence of peroxide gives….[NEET UG 2004]
- Assuming the expression for the pressure exerted by the gas on the walls of the container, it can be shown that pressure is...[MHT CET 2016]
- Which among the following is the strongest acid?...[TS EAMCET 2017]
- Isopropyl alcohol on oxidation forms..
- A vector is not changed if..
- Which of the following arrangements does not represent the correct order of the property stated against it?...[JEE Main 2013]
- The major product of the following reaction is...[JEE Main 2019]
- Major product of the following reaction is..[JEE Main 2023]
- The percentage of nitrogen in urea is about..
- The electric field at a point is
- Which of the following statements is true?..[JKCET 2006]
Sample Questions
Ques. Explain the term recombination with an example? (3 marks)
Ans. Recombination is defined as the genetic process in which strands of DNA are divided into smaller strands and recombine to form new molecules of alleles. The process of recombination takes place in sex cells through the process of meiosis. In natural things recombination is carried out by the process of crossover which results in the exchange of segments between chromosomes. The most common example of recombination is found in red hair and freckles which is found in human beings.
Ques. How many types of recombination are possible? (2 marks)
Ans. Recombination is divided into four categories namely Homologous Recombination, Non-Homologous Recombination, site specific recombination and mitotic recombination.
Ques. Explain the process of recombination? (3 marks)
Ans. The process of recombination is as follows:
- Wait for the maternal and paternal DNA to get aligned in the same phase.
- The maternal and paternal DNA align with the help of meiosis.
- During the process, the molecules of the required genes will interact and combine with each other.
- The process is smoothly carried out with the help of crossover.
- The frequency of recombination increases when the same DNA fragments recombine.
Ques. What is the meaning of the term genes? (2 marks)
Ans. Gene is defined as the unit of heredity which is made of the number of DNA. The genes are transferred from one parent to another parent at the time of offspring. There are two types of genes namely non coding genes and protein coding genes.
Ques. Explain the types of recombination? (3 marks)
Ans. There are four types of recombination which are as follows:
- Homologous Recombination: It is a type of recombination in which breaking and joining of DNA molecules take place in similar organisms.
- Non Homologous Recombination: This type of recombination is carried out in different organisms and also known as Illegitimate Recombination.
- Site specific recombination: This type of recombination takes place between molecules of dissimilar parents of short sequence.
- Mitotic Recombination: This is the last category of recombination which is carried out at the interphase between parent and maternal genes and is quite dangerous.
Ques. What are the differences between recombination and linkage? (3 marks)
Ans. The difference between recombination and linkage are as follows:
| Recombination | Linkage |
|---|---|
| Recombination is exchange of genetic material from one offspring to another offspring | Linkage refers to linkage of two or more genes which are present in the same chromosome. |
| It is based on law of assortment | It is not based on the law of assortment |
| The process is initiated when genes are far apart. | The process is initiated when genes are kept together. |
Ques. What is the meaning of the term heredity? (2 marks)
Ans. Heredity, also known as biological inheritance, is the process of transfer of genes from one parent to another parent at the time of either asexual reproduction or sexual reproduction. The study about the branch of heredity is called genetics.
Ques. Which method is used to carry out the recombination process? (1 mark)
Ans. Meiosis method is used to carry out the recombination process
For Latest Updates on Upcoming Board Exams, Click Here: https://t.me/class_10_12_board_updates
Check-Out:
Comments