Which one of the following genomes is most appropriate to determine hybrids in plants and animals?
Nuclear
Nuclear Genome for Hybrid Determination
When we talk about determining whether a plant or an animal is a hybrid, we need to look at the genetic material that comes from both parents. A hybrid organism is essentially a mix of genetic traits from two different parents, often from different varieties or species.
Let's consider the different genomes mentioned:
- Nuclear Genome: This is the primary genome found in the nucleus of eukaryotic cells. In most organisms, the nuclear genome is diploid, meaning it contains two sets of chromosomes — one set inherited from the mother and one set inherited from the father. Therefore, the nuclear DNA of a hybrid organism will contain a mix of genetic markers characteristic of both parental lines. By examining the nuclear DNA, we can identify genetic contributions from both parents, which is crucial for confirming and analyzing hybrid status.
- Mitochondrial Genome: Mitochondria have their own small, circular genome. In most animals and many plants, mitochondrial DNA (mtDNA) is inherited almost exclusively from the mother (maternal inheritance). This uniparental inheritance pattern means that the mitochondrial genome of a hybrid will largely resemble that of the female parent, with little to no contribution from the male parent. Therefore, mtDNA is useful for tracing maternal lineage but not for identifying contributions from both parents in a hybrid.
- Chloroplast Genome: Chloroplasts, found in plant cells, also contain their own genome (cpDNA). Similar to mtDNA, cpDNA inheritance is often uniparental, though the mode of inheritance (maternal or paternal) can vary depending on the plant species. If it's maternally inherited, like mtDNA, it would only reflect the female parent's contribution. If it's paternally inherited, it would only reflect the male parent's contribution. In either case of uniparental inheritance, the chloroplast genome alone cannot provide a complete picture of genetic contribution from both parents needed to confirm hybrid status effectively.
Based on the modes of inheritance, the nuclear genome is the most appropriate choice for determining hybrids in both plants and animals because it receives genetic material from both parents, allowing for the identification of combined parental genetic markers in the offspring.
Important Questions from Transgenic animals and plants
An experiment was performed to introduce a transgenic trait in a crop plant by Agrobacterium-mediated transformation using a transgene construct in which the transgene was expressed using the CaMV 35S promoter. It was observed that expression levels of the transgenic protein were very low in all transgenic plants while transgene mRNA levels were high and variable among different plants. Further, different transgenic lines contained different numbers of the T-DNA insert. The following statements were made to explain the above observation:
A. Variations in the number of T-DNA inserts in different transgenic plants is due to more number of host cells getting infected with the T-DNA
B. Low expression levels of the transgenic protein in all transgenic plants could be due to codon usage variations between the host plant and the heterologous source of the transgene
C. The coding sequence of the transgene contained sequences that destabilized the transgene mRNA
D. Variation in copy number of T-DNA in different transgenic plants is due to variation in the promoter used to express the transgene.
Which one of the following options represents all correct
statements?Following statements were given regarding factors influencing variation in expression levels of transgene in transgenic plants:
A. Difference in restriction enzyme sites within the T-DNA.
B. Difference in copy number of the transgene.
C. Variations in site of integration of the T-DNA within the plant genome.
D. Presence of multiple promoters within the T-DNA region.
Which one of the following options represents a combination of statements that would NOT lead to variations in transgene expression levels in transgenic plants generated using the same T-DNA/binary vector?
In Agrobacterium mediated transformation, which one of the following approaches is more likely to generate transgenic plants with INCOMPLETE transfer of the passenger gene?
Gene therapy is a promising tool for addressing several diseases in humans. With respect to the above, which one of the following statements is FALSE?
Given below are a few approaches/techniques used in the analysis of plants:
A. Phenotype linked to the marker gene.
B. PCR using primers specific to the host genome.
C. Southern hybridization
D. PCR using transgene-specific primers.
Which one of the following combination of approaches/techniques can be used to differentiate between transgenic and non-transgenic plants of a particular variety if the site of insertion is unknown?
