Thus, when lactose is absent the lac operon lactose operon repressor prevents synthesis of enzymes that metabolize lactose.
However, upon binding an inducer a molecule related to lactose the repressor loses this Ability and permits the production of enzymes. The arabinose operon C protein which is an activator causes making of arabinose enzymes on binding to the inducer arabinose.
Ans: Literally speaking palindrome is a word that reads the same backward and forward. The palindromic sequence is a region of a nucleic acid that contains a pair of inverted repeat sequences.
In a double stranded molecule of DNA such a region shows two-fold rotational dyad symmetry or hypemated dyad symmetry if the two IR sequences are separated by another sequence. A double-stranded palindromic sequence can adopt either of two possible formations:.
A cruciform structure in which of two strands each forms hairpins by intra-strand hydrogen bonding. Ans: Hermann Muller and L. Stadler discovered independently in that X-rays induce mutations. A cistron may also be defined as the functional unit of genetic inheritance a segment of genetic nucleic acid which codes for a specific polypeptide chain. The term cistron has also been used as a synonym for gene.
Ans: The term recon was coined by S. According to him it is a unit of genetic subdivision beyond which recombination does not occur. Ans: A mutator gene or mutator is designated as must within which certain mutations cause an increase in the spontaneous mutation rate in other genes, e. The mutant alleles may differ from the wild type, e.
The mutation may lead to reduced accuracy in the polymerising nucleotide selection activity or in the proof reading activity of the enzyme.
Some other mutator genes in E. Coli include in the mismatch repair system. Ans: The split genes may be defined as the genes that are coded for, by noncontiguous segments of the DNA so that the mRNA and the DNA for the protein product of that gene are not colinear.
7 Coarse Objective Questions. 1. Chapter 8 Essay Questions. 1. Describe 1) Function of enzymes, 2) Benefits of enzymes on molecules, Define the following: Genetics, chromosome, gene, genetic code, genetic recombination, codon. -Process used to visualize molecules three-dimensionally -Carries the genetic message of DNA to the protein-making machinery of the cell in the cytoplasm.
These are the genes with intervening nucleotide sequences not involved in coding for the gene product. The split genes have also been regarded as interrupted genes.
Thus mutation of the RNA transcript of a split gene must involve a process of splicing to delete the intron and join together the remaining sequences called exons. An introduction to the concepts and applications of genetics within the biological sciences.
Introduction to the module: key elements of genetics Mitosis and meiosis: Cell cycle and chromosome replication, Recombination and segregation, the basis of variability. Transmission Mendelian Genetics: Key concepts and vocabulary, Mendel's experimental approach, monohybrid and dihybrid crosses, Mendel's laws, deviations from complete dominance, gene interactions, polygenic traits, chromosome theory, X-linked traits, chromosomal anomalies, pedigree analysis.
Translation: Ribosome structure, RNA molecules, mechanism of protein synthesis.
Regulation of gene expression, Eukaryotic regulation. Recombinant DNA technology: Components of the technology and applications. What is a cell?
What does DNA do? What is gene expression? Giants in genomics: Francis Crick. Is this page helpful? Yes No. Anything else you'd like to see? What were you looking for?