Lecture 9 - Origins Of Variation In Genomes: Recombinatiom Flashcards
What is the primary function of mitosis?
Somatic cell division to produce genetically identical daughter cells
Mitosis results in two diploid (2n) cells from one diploid cell.
In haploid organisms, what is the outcome of mitosis?
1n -> 1n + 1n
This indicates that haploid cells divide to produce two haploid cells.
What is the primary outcome of meiosis?
Haploid gamete production, resulting in genetically different daughter cells
Meiosis involves two rounds of division leading to four haploid (n) cells.
What occurs during homologous recombination?
Reciprocal exchange of genetic material
This process occurs during prophase of meiosis I.
What is the significance of chiasmata in meiosis?
Visible crossings formed during crossing over between homologous chromosomes
Chiasmata are crucial for genetic diversity.
What is the role of Spo11 and Mre11 in homologous recombination?
They cut chromosomes, causing double strand breaks
These breaks are essential for the recombination process.
What are the two main methods of repairing DNA double strand breaks?
Non homologous end joining and homologous recombination
Homologous recombination is generally preferred due to its accuracy.
What is a disadvantage of non homologous end joining?
It can result in missing genetic information due to degradation
This method can lead to larger genetic defects.
What is the benefit of homologous recombination compared to non homologous end joining?
Less damage and accurate repair using sister chromatids
This repair mechanism utilizes the intact sister chromatid for accurate restoration.
What is heteroduplex (D-loop) formation?
A dynamic three-stranded structure formed during homologous recombination
It involves Rad51 binding to single-stranded DNA to search for homologous sequences.
What does linkage analysis reveal about genes on a chromosome?
Genes are physically and genetically linked
This analysis helps in mapping genes based on recombinant frequency.
How is recombinant frequency related to the distance between linked genes?
Recombinant frequency is proportional to the distance apart
Higher recombinant frequency indicates greater distance between genes.
True or False: Homologous recombination is a universal process.
True
This process occurs across eukaryotic organisms.
Fill in the blank: Homologous recombination is a method of _______ during DNA repair.
accurate repair
It ensures the precise restoration of damaged DNA.
What is the outcome of homologous recombination during meiosis?
Genetic rearrangement and diversity
This process is essential for evolution and adaptation.
