Nuclear membrane - structure of nucleus, Biology

Assignment Help:

KARYOTHECA OR NUCLEAR MEMBRANE

It is also called Nucleolemma, term given by Erclab & Hertwig.
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.
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.
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.
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 .

Related Discussions:- Nuclear membrane - structure of nucleus

Apical window, The transducer is placed in the mid axillary line with ...

The transducer is placed in the mid axillary line with the transducer ridge pointing towards the patients left to obtain the four-chamber view. The left ventricular apex is

Decomposers - biotic components, Decomposers - Biotic Components Also ...

Decomposers - Biotic Components Also known as saprotrophs. Mostly, these are microscopic and are heterotrophic in nature. Decomposer organisms obtain their energy and nutrient

How to determines the actual availability of nutrients, How to determines t...

How to determines the actual availability of nutrients The amount of a particular nutrient determined analytically does not necessarily represent what is available but is merel

On which type of basis you classify the plants, Q. On which type of Basis y...

Q. On which type of Basis you classify the plants? Linnaeus mainly employed the characters of stamens and carpels and that is why the system is called as Sexual system of class

Differance among subphylum chaetognatha and urochordata, Explain differance...

Explain differance between Subphylum Chaetognatha and Subphylum Urochordata? Subphylum Chaetognatha: Larval stages of this small group share some of the characteristics with

Optional use values of biodiversity, Q. Optional use values of biodiversity...

Q. Optional use values of biodiversity? Optional values are associated with potential use in the future. Accordingly one opts to conserve biodiversity based on the hope that it

How to identify the metal out of which the wire is made, A wire 50.0 m long...

A wire 50.0 m long and 2.00 mm in diameter is connected to a source with a potential difference of 9.11 V, and the current is found to be 33.7 A. Assume a temperature of 20°C and,

Cardiac catheterization and angiography, Q.Define Cardiac catheterization a...

Q.Define Cardiac catheterization and angiography? The purpose of this unit is to give you an overview and insight into the world of Cardiac Catheterization and Angiography. Thi

Are the limbs modified into wings of bats, Are the limbs modified into wing...

Are the limbs modified into wings of bats and the wings of birds examples of evolutionary analogy or homology? What about whale fins compared to fish fins? Bat and bird wings h

Preparation of the standard curve for haemoglobin, Preparation of the stand...

Preparation of the standard curve for haemoglobin? Label 6 clean dry rest tubes and label them as S1 -S6 Add 5 ml of Drabkin's solution to test tube numbers S2 - S6

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages