In this article we will discuss about the Structure and Function of Microtubules and Cytoskeleton in Cell. Structure of Microtubules and Cytoskeleton in Cell: Microtubules are long, hollow tubular cylinders with an outer diameter of 250Å. The wall thickness is about 50Å, leaving a hollow core of about 150Å diameter. The length of microtubules varies from a fraction of a [...]
The following points highlight the three main constituents of nucleus. The constituents are: 1. Nuclear Envelope 2. Nucleolus 3. Nucleoplasm. Constituent # 1. Nuclear Envelope: Under the electron microscope the nuclear envelope appears to consist of two membranes, the outer and the inner nuclear membranes, separated by a perinuclear space of 20 nm (Fig. 2.65). Each of the two membranes [...]
The following points highlight the top six types of hypothesis with respect to origin of eukaryotic cell. The hypothesis are: 1. Independent Hypothesis 2. Endogenous Theory (Filiation Theory) 3. Chimera Hypothesis 4. Endosymbiotic Theory 5. Serial Endosymbiotic Theory (Set) 6. Syntrophy Hypothesis. Type # 1. Independent Hypothesis: The unique nature of the eukaryotic nucleus with structurally complex chromosomes is thought [...]