The Human Genome Project constituted a collaborative and global scientific endeavor aimed at elucidating the sequence of nucleotide base pairs comprising human DNA. Its overarching objectives included the comprehensive identification and mapping of all human genome genes, undertaken with a dual focus on both the physical and functional dimensions of genetic information. Following are the … Read more
The role of lactose in in ‘lac operon’ are-: 1. A low level of beta-galactoside permease enzyme persists in the cell even when the Lac operon is inactive, allowing minimal lactose entry. 2. Lactose binding to the repressor renders it inactive. 3. The repressor-lactose complex loses its ability to bind to the operator gene, leading … Read more
DNA fingerprinting, is a technique that analyzes the unique characteristics of DNA molecules to identify individuals. It creates a distinct DNA profile, much like fingerprints, allowing for individual identification and analysis. Applications of DNA finger printing: 1. Forensic science aids in pinpointing potential suspects. 2. Establishing blood relationships is a key function. 3. Identification and … Read more
The several key features of the genetic code are: 1. Commaless Structure: The genetic code exhibits a commaless arrangement, where triplet codons on m-RNA follow one another seamlessly without gaps. This absence of commas in the sequence is a distinctive feature. 2. Non-ambiguous Nature: Each codon holds the unique ability to specify a particular amino … Read more
1. Eukaryotic cell DNA (2.2 meters) undergoes condensation, coiling, and supercoiling for efficient packaging in the nucleus (10-16 meters). 2. DNA associates with both histone and non-histone proteins. 3. Histones, positively charged basic proteins, are rich in lysine and arginine amino acid residues. 4. The nucleosome consists of a nucleosome core with two molecules each … Read more
The Chromosomal Theory establishes chromosomes as carriers of genetic material and puts forth the following principles: Hereditary traits are transmitted through gametes, the reproductive cells formed by the parents (sperms and ova), acting as a link between parents and offspring. Chromosomes within the nucleus of gametes serve as the vehicles for transmitting all hereditary characteristics. … Read more
Let’s compare the characteristics of X-chromosome and Y-chromosome: X-chromosome: 1. It is a straight, rod-like chromosome longer than the Y chromosome and is metacentric. 2. It contains a significant amount of euchromatin and a smaller amount of heterochromatin. 3. With a large DNA content, it is genetically active, housing numerous genes. 4. The non-homologous region is … Read more
Phenylketonuria (PKU) is a genetic condition due to a shortage of the enzyme phenylalanine hydroxylase. This deficiency leads to an accumulation of phenylalanine in the body, disrupting protein balance. Phenylalanine is found in all proteins and certain artificial sweeteners. The enzyme shortage hampers the conversion of phenylalanine into tyrosine, crucial for neurotransmitter production. PKU arises … Read more
Linkage in genetics means genes on the same chromosome tend to be inherited together, affecting how traits are passed down. Humans have 23 pairs of chromosomes. Each chromosome forms a linkage group. Therefore, there are 23 linkage groups in human beings.
In humans, the determination of a child’s sex is based on the combination of sex chromosomes inherited from both parents. However, the father’s contribution is crucial in determining the sex of the child due to the nature of sex chromosomes. The father contributes both an X and a Y chromosome in his sperm. Meanwhile, the … Read more