3. Double-stranded breaks are potentially lethal, unless they are repaired. 4. Repair systems in the cell correct the double-stranded breaks by joining bro- ken ends back together (see Chapter 16 for a detailed discussion of DNA repair). FIGURE 17-19 Each of the four types of chromosomal rearrangements can be produced by either of two basic mechanisms: chromosome breakage and rejoining or crossing over between repetitive DNA. Chromosome regions are numbered 1 through 10. Homologous 5. If the two ends of the same break are rejoined, the original DNA order is re- stored. If the ends of two different breaks are joined, however, one result is one or another type of chromosomal rearrangement. 6. The only chromosomal rearrangements that survive meiosis are those that produce DNA molecules that have one centromere and two telomeres. If a chromosomes are the same color. Origins of chromosomal rearrangements Breakage and rejoining Crossing over between repetitive DNA Deletion -3 2 Loss 32 4 Loss Deletion and duplication 3 4 23 23 4 Inversion ! 10 10 Translocation 10 6 2 Chromosome break - Joining of broken ends Repetitive DNA segments X Crossover

Q: During meiosis when crossing over occurs in a paracentric inversion loop, what percent of the…

A: Meiosis is the process of cell division that produces four daughter cells from a single cell. These…

Q: In humans, chromosome 16 sometimes has a heavily stained area near the centromere. This feature can…

A: So, non disjunction of the chromosomes occurs in the condition when the homologous chromosomes fail…

Q: The Y chromosome contains large amounts of constitutive heterochromatin. Why might there be more…

A: Constitutive heterochromatin is generally found in the centromere regions and also, at the telomere…

Q: An inversion heterozygote has the following inverted chromosome. (A diploid is represented in each…

A: PERICENTRIC INVERSIONS PERICENTRIC INVERSION includes the centromere. After the chromatid…

Q: why The chromatids formed byrecombination within the inversion loop of a pericentric…

A: When the region between two breaks of the same chromosome rotate 180°, it results in chromosomal…

Q: Are forward and reverse primer are complementry to each other ?

A: Forward primers: Forward primers are one of the two types of primers used in a PCR setup. The main…

Q: What genetic process is occurring in a puff of a polytene chromosome? How do we know this…

A: Puffs in polytene chromosomes are the Balbiani rings.

Q: The two telomeric loop structures are formed by invasion of the 3' single-strand overhang. Draw the…

A: The chromosomes of the eukaryotes end in telomeres, which consist of tandem repeats of a short…

Q: Why do you think there are no viable trisomies of chromosome 1?

A: Chromosome 1 is the largest chromosome in human. Approximately 8% of the total DNA is found in this…

Q: What genetic process is occurring in a puff of a polytene chromosome?

A: Polytene chromosomes, also known as giant chromosomes, are commonly found in the cells of salivary…

Q: What is the diagnostic test for linkage?

A: Chromosomes are the condensed form of DNA that carry all the genes.  Genes are represented in the…

Q: In Neurospora, his2 mutants require the amino acidhistidine for growth, and lys4 mutants require…

A: Neurospora is a type of a fungus that has axon like striations on its spores. The spores of the…

Q: Explain why inversions and reciprocal translocations do not usually cause a phenotypic effect. In a…

A: in this, no addition or removal of genetic material is done there is a relative change in the…

Q: What is pseudodominance and how is it produced by a chromosome deletion?

A: The expression of typically recessive transformation that is created when the dominant wild sort…

Q: Which chromosome rearrangements can cause deletions and duplications?

A: A chromosome is a thread like structure present in the nucleus of the cell. It contains the DNA and…

Q: what is Unequal crossing-over between duplications ?

A: Crossing over is the process during which the non-sister chromatids of a homologous pair of…

Q: Does mitotic recombination occur in a gamete (sperm or egg cell) or in a somatic cell?

A: Cell division is typically a part of a broader cycle of cells. There are two distinct forms of cell…

Q: mosome disorder explain with examples.

A: Almost each cell in our body contains 23 pairs of chromosomes, for a complete of forty six…

Q: Explain why when a chiasma is formed, only 50% of the meiotic products will be of recombinant type.…

A: Chaismata  are the points on Homologus chromosomes where crossing over takes place between…

Q: What kind of chromosomal mutations is/are produced by unequal crossing over?

A: Mutation refers to both the process of altering a gene or chromosome and the outcome of that…

Q: What occurs during duplication chromosomal mutation?

A: Mutations are defined as sudden heritable change which alters the expression of a gene.

Q: With detailed accounts of their various forms, explain any three of the following chromosomal…

A: Mutations may be defined as the changes that occur in a DNA sequence. They are the raw materials for…

Q: Why does chromosome 21 come first before chromosome 22? If chromosome 21 is smaller than chromosome…

A: Chromosome diseases are genetic illnesses caused by chromosome mutations. Chromosome diseases are…

Q: Inversions are known to affect crossing-over. The following homologs have the indicated order (the…

A: Thank you for the question.  Answer : inversion is when there is disruption of a single chromosome (…

Q: Why are people with balanced chromosomal translocations phenotypically normal? Do they suffer from…

A: Chromosomal translocations are genomic events in which either a part or the entire chromosome breaks…

Q: Two nonhomologous chromosomes have the following segments, where * represents the centromere:…

A: Two nonhomologous chromosomes have the following segments, where * represents the…

Q: L, R, P and D are four genes located on the same chromosome in a diploid organism. Map distances…

A: Genetic mapping is a technique to determine the relative position of genes on a chromosome and their…

Q: Two phenotypically normal parents produce an abnormal son in which chromosome 14 is missing part of…

A: Translocations are chromosomal rearrangements caused by the exchange of components between two…

Q: What are the half-circle rotations of a chromosomal region?

A: Chromosomes appear at the time of cell division in the form of thread like structures inside the…

Q: The radish (Raphanus sativus) has a diploid number (2n) of 18. The cabbage (Brassica oleracia) also…

A: Plant breeding is an important part of agriculture, and it has been used for generations to increase…

Q: his area of the chromosome iIS 5%.

A: Introduction  Linkage disequilibrium (LD) is the nonrandom relationship of alleles of various loci.…

Q: With two pairs of homologous chromosomes, four kinds of gametes can be produced. How many kinds of…

A: Gametes are formed by the process of meiosis in the gamete mother cells.

Q: What is a microdeletion?

A: Chromosomes are structures present in the nucleus of the cell. The chromosomes are formed of DNA…

Q: What is nonautonomous transposition?

A: Transposition refers to the translocation in which the segment of the chromosome is relocated…

Genetic Recombination

Recombination is crucial to this process because it allows genes to be reassorted into diverse combinations. Genetic recombination is the process of combining genetic components from two different origins into a single unit. In prokaryotes, genetic recombination takes place by the unilateral transfer of deoxyribonucleic acid. It includes transduction, transformation, and conjugation. The genetic exchange occurring between homologous deoxyribonucleic acid sequences (DNA) from two different sources is termed general recombination. For this to happen, an identical sequence of the two recombining molecules is required. The process of genetic exchange which occurs in eukaryotes during sexual reproduction such as meiosis is an example of this type of genetic recombination.

Microbial Genetics

Genes are the functional units of heredity. They transfer characteristic information from parents to the offspring.