Category: cell biology
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Cell Division – Meiosis
Introduction Process by which chromosome number of a diploid cell (2n) is reduced to half i.e. it changes to haploid (n). Results in daughter cells differing from parent cell, genetically. Resulting haploid cell either directly becomes gamete or differentiate/divide to produce cell that later becomes a gamete. Plays a key role in eukaryotic reproduction. Homologous…
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Cell Cycle & Cell Division – Mitosis
Key points: Chromosomes are cellular structures. They carry genes & are composed of DNA, RNA & proteins. Haploid Eukaryotic Cell contains one copy of each chromosome. Diploid Eukaryotic Cell contains two copies of each chromosome. Prokaryotic Cell divide by fission. Eukaryotic Cell divide by Mitosis & Cytokinesis. Most gametes are formed by Meiosis. ‘Cell Cycle’…
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Prokaryotic & Eukaryotic Cells
Living World is classified into 3 division or domains, namely: 1) Bacteria (Eubacteria) 2) Archaea (Archae-bacteria) 3) Eukaryotes Bacteria & Archaea are grouped separately under Prokaryotes. Since, Viruses lack metabolic apparatus & considered non-living outside host cell, they are classified separately from the above divisions. Examples: Bacteria – Escherichia coli, Lactobacillus, Mycoplasma, Cyanobacteria etc. Archaea…
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Plasma Membrane – Phospholipid Bilayer
Mammalian Red Blood Cells Provided initial evidences that biological membranes consist of lipid bilayers (E. Gorter & F. Grendel, 1925). Since, they do not contain nuclei or internal membranes, thereby becoming a source from which pure plasma membrane can be isolated easily. RBCs’ plasma membrane have been particularly useful as a model for membrane structure…