Central cell - synergids, Biology

Assignment Help:

Central Cell - Synergids

It is the largest cell of the embryo sac, and the mother cell of the endosperm. The enlargement of the embryo sac after the last nuclear division is mainly due to the inflation of the large central vacuole of the central cell. The vacuole in the central cell is presumably the reservoir of sugars, amino acids and inorganic salts. The nuclei of the central cell, also called the polar nuclei, are very large, and are characterized by a conspicuous nucleolus. They are present either in the centre of the cell, suspended by cytoplasmic strands, or in the cytoplasm close to the egg apparatus. In the latter case the chalazal portion of the embryo sac is occupied by a large vacuole. The two polar nuclei fuse before or during double fertilization to form the secondary nucleus.

The cytoplasm of the central cell is rich in plastids, mitochondria, numerous, dictyosomes, and ribosomes or small polysomes. This cell appears to be the centre of intensive synthetic activity in the embryo sac. The thickness of the central cell wall is variable. It is thickest in the regions in contact with the nucellus. Where the central cell touches the egg and synergids, it shows the common feature of partial wall. It becomes thinner towards the chalazal end of the egg apparatus, and finally, in the chalazal region there is no wall between the plasma membranes of the central cell and those of the egg and the synergids. The central cell is connected along with the.egg, synergids, and the antipodals through plasmodesmata connections.


Related Discussions:- Central cell - synergids

Explain the properties of good prebiotic, Explain the Properties of Good Pr...

Explain the Properties of Good Prebiotic? Thus, to summarize, we can say that a good prebiotic should have the following properties: Be active at a nutritionally feasibl

Define serum vitamin a content, Define Serum Vitamin A Content? Assessm...

Define Serum Vitamin A Content? Assessment of serum vitamin A content is the most reliable criterion Tor assessing vitamin A status. Serum levels indicative of various degrees

Resemble the homozygous recessive parental, A dihybrid cross yields 320 F2 ...

A dihybrid cross yields 320 F2 offspring. How many are expected to resemble the homozygous recessive parental?

Is protein collagen has a high proportion of glycine, The protein collagen ...

The protein collagen has a high proportion (20% or more) of A. asparagine and glutamine B. proline and hydroxyproline C. glycine D. both A and B E. both A and C F

Skeleton - animal kingdom, Skeleton - Animal Kingdom You all know that...

Skeleton - Animal Kingdom You all know that the skeleton forms the framework of the body of different organisms in the animal kingdom. Besides giving shape to the animal, it a

What is alternate splicing, Which of the following is a true statement rega...

Which of the following is a true statement regarding alternate splicing? A. Alternate splicing permits for an increase in protein diversity by the differential use of exons whe

Explain procedure for sub-culturing of a culture, Explain Procedure for Sub...

Explain Procedure for Sub-Culturing of a Culture Now carry out the exercise following the steps given herewith: 1. Sterilize the inoculating loop and needle by heating to re

Explain the sub-culturing, Explain the Sub-Culturing? Microbiological s...

Explain the Sub-Culturing? Microbiological studies require microorganisms in pure form, i.e., a single type of microorganisms should be present in a culture. Maintenance of the

What are the micronutrients, What are the Micronutrients   All the micr...

What are the Micronutrients   All the micronutrients except molybdenum, boron and chlorine are available more in acid soils. These elements may limit plant growth either becaus

Biodeterioration, is paper broken down by microorganisms

is paper broken down by microorganisms

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