Obturator - ovule, Biology

Assignment Help:

Obturator - Ovule

An obturator is an outgrowth of the placenta or funicle or integument or style near the micropyle. It is presumed to guide the pollen tube to the micropyle. This tissue is either composed of thin-walled compact tissue or it is made up of loose hairy outgrowths. The cells of the obturator at the ultra structural level, show dense cytoplasm containing a copious number of ER, dictyosomes, and vesicles. The cells of the obturator produce a surface exudate and provide mechanical and chemical guidance to the growing pollen tube.

323_Obturator.png

Figure:  Obturator in Tetragonia tetragonioides


Related Discussions:- Obturator - ovule

Differentiate between the five kingdoms of organisms, Question 1: (a) G...

Question 1: (a) Give, in order, the major categories of taxonomic classification. (b) Differentiate between the five kingdoms of organisms. (c) Differentiate between net

Who could be the parents of a child, This problem refers to the MN and ABO ...

This problem refers to the MN and ABO loci mentioned in class. It also refers to the Rh locus, which is responsible for the positive/negative part of the blood type. The Rh+ allele

DNA REPAIR, assignment for discussing DNA REPAIR

assignment for discussing DNA REPAIR

Explain precautions for detection of metanil yellow, Explain Precautions fo...

Explain Precautions for Detection of Metanil Yellow? 1. One should be careful while using concentrated HCl otherwise it may result in burn. 2. Amount of concentrated HCl in

Which keel is characteristic of the flowers, Keel is characteristic of the...

Keel is characteristic of the flowers of : 1. Gulmohur 2. Cassia 3. Calotropis 4.  Bean Bean

What is sarcoplasmic reticulum, An increase in the calcium conductance of a...

An increase in the calcium conductance of all sarcoplasmic reticulum membranes of a skeletal muscle with no external forces on it leads to A. an increase in the amount of calci

Explain about the secondary protein derivatives, Explain about the Secondar...

Explain about the Secondary Protein Derivatives? These are the products of further hydrolytic cleavage of the protein molecule, Examples include: a) Proteoses: Soluble in wa

How does phosphorus cycle vary from carbon cycle, (a) Trace the succession ...

(a) Trace the succession of plants on a dry bare rock. (b) How does phosphorus cycle vary from carbon cycle?

What are the main harms caused by vitamin a deficiency, What are the main h...

What are the main harms caused by vitamin A deficiency? How does this vitamin act in the physiology of vision? Deficiency of vitamin A (retinol) might be cause night blindness

What are the proportions of gametes, An organism having the genotype AaBbCc...

An organism having the genotype AaBbCcDdEe is self-fertilized. What are the proportions of gametes that are expected to carry only dominant alleles?

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