Nuclear membrane - structure of nucleus, Biology

Assignment Help:

KARYOTHECA OR NUCLEAR MEMBRANE

  1. It is also called Nucleolemma, term given by Erclab & Hertwig.
  2. Karyotheca composed of two unit membranes separated by a 150-300 A° wide perinuclear space. Outer membrame may have 80s ribosomes.E.R. is connected to outer nuclear membrane at several places.
  3. Just beneath inner nuclear membrane, there is a fibrous layer called fibrous lamina. It provides strength to nuclear membrane and also provides attachment site to peripheral heterochromatin.
  4. Nuclear membrane is perforated by nuclear pores of 400 - 1000 Aº diameter with space 1500 Aº . In the oocyte of frog (Xenopus laevis) 30 million nuclear pores are present. Nuclear pores are covered by an octagonal structure composed of eight granular subunits called Annulus or Bleb. Anulus and nuclear pore collectively called pore complex.
  5. These pores regulates transport bet. nucleoplasm and cytoplasm, Small ions like K+, Na+ and Cl- move through nuclear membrane while t-RNA ,r-RNA and m- RNA pass through nuclear pores. Protein nucleoplasmin which occur in pore complex regulates the nucleo cytoplasmic traffic .

357_nucleus.png


Related Discussions:- Nuclear membrane - structure of nucleus

Describe microtubular cytoskeleton in protozoans, Protozoans have endoskele...

Protozoans have endoskeletons formed from microtubular cytoskeleton of the exoskeletons or cytoplasm secreted as shells or tests. Some of these single-cell organisms are capable of

Meningocele, Meningocele In this the meninges protrude through the op...

Meningocele In this the meninges protrude through the opening in the vertebrae generally in the lower back. The sac contains meninges and cerebrospinal fluid. The sac may

Explain the anaesthesia and analgesia, Explain the Anaesthesia and Analgesi...

Explain the Anaesthesia and Analgesia Most implant surgery can be carried out under local anaesthesia, although some patients will require sedation or general anaesthesia. The

Michaelis menten, Regulation of enzymatic action equations for competitive,...

Regulation of enzymatic action equations for competitive, non-competitive, uncompetitive inhibition and mixed reaction

What is polyethylene, Q. What is Polyethylene? Polyethylene (P) (Low de...

Q. What is Polyethylene? Polyethylene (P) (Low density polyethylene (LDPE), medium density, linear low-density (LLDPE), high-density polyethylene (HDPE) and ethylene vinyl acet

How age factors affecting the calcium absorption, How Age factors Affecting...

How Age factors Affecting the calcium absorption? Age is another factor which influences the absorption of calcium. Fractional absorption of calcium is highest in infancy i.e.,

State the term - symbolic representation, State the term - Symbolic represe...

State the term - Symbolic representation Symbolic representation is the representation of both the external and internal world through symbols and has been discussed in relatio

First stage of invagination, First Stage of Invagination The large en...

First Stage of Invagination The large endodermal cells that are remaining in the vegetal plate move laterally towards the centre of the plate and fill the gap in the vegetal

How do arthropods grow, How do arthropods grow? Because of the presence...

How do arthropods grow? Because of the presence of exoskeleton the growth of an arthropod is periodical. During the growth period the animal loses the exoskeleton, grows and de

Indications for gingival curettage - endodontic surgery, Indications for Gi...

Indications for Gingival Curettage - Endodontic Surgery a) Persistent periradicular pathosis following endodontic treatment, b) Periradicular lesion that enlarges after endo

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd