Thalassemia It occurs due to an autosomal recessive gene, that expresses in homozygous condition. Two carrier or heterozygous parents can produce an affected child. This genetic defect originated in Mediterranean region due to mutation or deletion in the genes controlling the synthesis of globin chains of Haemoglobin. It also occurs …
Pleiotropy Pleiotropy is a condition in which single gene affects many characters or single gene affects many phenotypes. It occurs due to inter-relationship between metabolic pathways that contribute to the formation of the different phenotype. Effect of the gene is more evident in one trait and less evident in other …
Polygenic Inheritance: Polygenic inheritance is controlled by two or more pairs of nonallelic genes. In which the dominant alleles have a cumulative effect. Each dominant gene added will add to the character and the result will be an additive effect of all dominant genes. These genes are Polygenes and such type of …
Sex-Linked Inheritance: T H Morgan while working on eye color in Drosophila, found that the gene for eye color did not follow the Mendelian pattern of Inheritance. This was due to the gene being present on the X-chromosome. Genes present on the X-chromosome are known as Sex-linked genes, the characters …
DNA A polymer of deoxyribonucleotides. Length is defined as the number of nucleotides or nucleotide pairs present. This is the characteristic of an organism. Bacteriophage Ø x174 has 5386 nucleotides. Bacteriophage λ has 48502 base pairs. Escherichia coli has 4.6 x 106 base pairs. The haploid genome of human DNA …
DNA fingerprinting DNA fingerprinting is a technique to identify an individual by looking at unique patterns in their DNA. In human’s 99.9% of the base sequences of DNA are same & are referred as Bulk genomic DNA. The difference lies in remaining 0.1%. It is these differences which make every individual unique …
Regulation of gene expression It is the metabolic, physiological or environmental conditions that regulate the expression of genes. Housekeeping or constitutive genes: genes whose products are continuously required by the cell hence they continuously transcribe and translate. Non-constitutive genes: genes whose products are not continuously required by the cell & if they …
CELL DIVISION: Mitosis & Meiosis Cell Cycle Can be divided into 2 stages: INTERPHASE. G1 Growth phase 1. S Synthetic phase. G2 Growth phase 2. During Synthetic phase, DNA duplicates. The genetic material doubles mean from 2N it becomes 4N. DIVISIONAL PHASE. M Mitosis/Meiosis. C Cytokinesis. Mnemonic:“Go Sally Go! Make …
Linkage A chromosome possesses many genes & all genes present in the chromosome are inherited together. Linkage: Study of inheritance of all genes present in a chromosome together. All genes in a chromosome are together referred as linked genes & they form a linkage group. The total number of linkage …
Cell Cycle “Go Sally Go! Make Children!” Can be divided into 2 stages: INTERPHASE: G1 Growth phase 1. S Synthetic phase. G2 Growth phase2. DIVISIONAL PHASE: M Mitosis/Meiosis. C Cytokinesis. …
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