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

Animal classification, Explain metachrosis in frogs? How it is different fr...

Explain metachrosis in frogs? How it is different from change of skin colour of chemleon?

Vitamins necessity, Vitamins necessity Vitamins are essential organi...

Vitamins necessity Vitamins are essential organic substances. They are micro nutrients and required in small quantities. They do not produce any energy by themselves.

Basics of echocardiography, Echocardiography is one of the -most frequent...

Echocardiography is one of the -most frequently used imaging modalities for diagnosing cardiovascular diseases. It i's versatile and is applicable in the entire spectrum of

Are the extraembryonic membranes the same in all vertebrates, Q. Are the ex...

Q. Are the extraembryonic membranes the same in all vertebrates? The presence of each extraembryonic membrane differs according to the vertebrate class. In amphibians and fi

Ethylene - apical dominance, Ethylene - Apical Dominance Ethylene also...

Ethylene - Apical Dominance Ethylene also plays a role in the inhibition of lateral bud growth. It is present in those tissues like shoot apex where auxins are also present. I

Feature of the hookworms related to the way they obtain food, Q. Which is t...

Q. Which is the typical feature of the hookworms related to the way they obtain food and explore the host? Both The Necator americanus and Ancylostoma duodenale have mouthparts

O-linked oligosaccharides , Most proteins made by ribosomes on the RER (rou...

Most proteins made by ribosomes on the RER (rough endoplasmic reticulum) are glycoproteins, which is they hold short chains of carbohydrates (oligosaccharides) covalently related t

What are the trends of the gametophyte, What are the trends of the gametoph...

What are the trends of the gametophyte in the evolution of plants? A tendency of the gametophyte evolution in plants has been towards the formation of gametes that are independ

Rapidly flowing waters - biota of rivers, Rapidly Flowing Waters - Biota of...

Rapidly Flowing Waters - Biota of Rivers In the rapidly flowing section of the river, the water current is the dominant feature. Everything that is not attached or weighed is

Respiration, what are the organs of respiration in lower forms of animals?

what are the organs of respiration in lower forms of animals?

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