Application of Genetics in Breeding

Application of Genetics in Breeding

1. Sources of genetic material for breeding:

• Recombination variation: Occurs due to the random combination of genes from parents, generating various new genotypes and phenotypes.

• Mutation: Sudden changes in the structure of genes or chromosomes, leading to new alleles.

• Recombinant DNA: DNA molecule created by combining DNA segments from different sources, resulting in new genes.

2. Heterosis:

• The phenomenon where F1 hybrids exhibit superior productivity, disease resistance, growth rate, and development compared to their parental forms.

3. Process of breeding for high heterosis:

• Creating inbred lines: Utilizing forced self-pollination or inbreeding to produce pure lines.

• Crossing different inbred lines: Crossing different inbred lines to produce F1 hybrids.

• Selecting combinations with high heterosis: Selecting hybrid combinations with the highest heterosis for production.

4. Process of breeding through mutation breeding:

• Treating specimens with mutagens: Using mutagens like radiation or chemicals to induce mutations in genetic material.

• Selecting mutated individuals with desired phenotypes: Selecting mutated individuals with the desired phenotype to create new breeds.

• Creating inbred lines: Using forced self-pollination or inbreeding to create inbred lines from selected mutated individuals.

5. Genetic engineering:

• The process of creating cells or organisms with altered genes or introducing new genes.

6. Enzymes involved in gene transfer technology:

• Restriction enzymes: Cut DNA at specific sites.

• Ligase: Joins DNA segments together.

7. Vectors used in gene transfer technology:

• Plasmids: Small circular DNA molecules capable of independent replication within bacterial cells.

• Viruses (bacteriophages): Viruses that infect bacteria, carrying foreign genes into bacterial cells.

8. Purpose of forced self-pollination and inbreeding in breeding:

• Creating inbred lines, facilitating genotype determination of individuals.

9. Genotype of diploid plants produced from pollen or ovule culture:

• Homozygous for all genotypes.

10. Cell type used in cell fusion:

• Heterospecific somatic cells.

11. Reason for the highest expression of heterosis in F1 and its decline across generations:

• Due to self-pollination across generations: The frequency of heterozygous genotypes decreases, while the frequency of homozygous genotypes increases, leading to the expression of recessive harmful genes in phenotypes.

12. Applications of genetic engineering in producing substances:

• Insulin, somatostatin, vaccines.

13. Characteristics of the plasmid vector:

• Ability to replicate independently.

14. Genetic engineering:

• Manipulation of genes, transferring genes from one cell to another.

15. Artificial mutation breeding method particularly effective for which type of organism:

• Microorganisms.

16. Commonly used vectors in gene transfer technology:

• Plasmids and bacteriophages.

17. Chemical used to induce polyploidy in plant breeding:

• Colchicine.

18. Processes involved in breeding through cell technology:

• Pollen or ovule culture.

• Protoplast fusion.

• Animal cloning.

• Embryo transfer.

19. Method used to create recombinant variations in animal breeding:

• Sexual hybridization.

20. Method for widening the cell membrane to allow recombinant DNA to pass through in gene transfer technology:

• CaCl2 or electric pulses.

21. Definition of recombinant DNA:

• A small DNA molecule assembled from DNA segments derived from different sources.