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

Invertebrates - osmotic and ionic regulation, Invertebrates - Osmotic and I...

Invertebrates - Osmotic and Ionic Regulation Regulation of water and ions in invertebrates is done by neuroendocrine mechanism. It operates at the level of Malpighian tubules

Explain metabolic response to injury, Explain Metabolic Response to Injury?...

Explain Metabolic Response to Injury? There is an increase in the basal metabolic rate above the normal. The degree of hyper metabolism is related to the severity of the injury

Explain the impedance method to measure body fats, Explain the Impedance me...

Explain the Impedance method to Measure Body Fats? Impedance method: This method can give entire body composition like total body water (TBW), fat free mass (FFM) or lean body

Diarrhoeas disease, Diarrhoeas disease: Diarrhoeas disease rank among ...

Diarrhoeas disease: Diarrhoeas disease rank among  th most leading causes of children's death in developing countries. We shall discuss two main problems in this section i.e.

Are the xylem and the phloem made of living cells, Are the xylem and the ph...

Are the xylem and the phloem made of living cells? The cells that constitute the xylem ducts are dead cells killed by lignin deposition. The cells of the phloem are living

Values of dpd for plant cells under hypertonic media, Q. What are the value...

Q. What are the values of DPD for plant cells under hypertonic, hypotonic and isotonic media? In plant cells under hypertonic medium there is loss of water for the external, SF

Transition of the vertebrates, Q Which is the chordate class considered an ...

Q Which is the chordate class considered an evidence of the transition of the vertebrates from the aquatic to the dry land environment? The amphibians are totally aquatic in th

Eye muscles, MUSCLES - In eye orbit, eye ball is fixed by 6 skeletal...

MUSCLES - In eye orbit, eye ball is fixed by 6 skeletal muscles attached to 3rd, 4th & 6th cranial nerves (motor). 4 - straight or recti muscles are present. 2 - oblique

What are the reagents and products of fermentation, In general what are the...

In general what are the reagents and products of fermentation? In fermentation glucose (sugar) is degraded into pyruvic acid (every glucose molecule forms two pyruvic acid mole

Explain phylum cnidaria - coelenterates, Explain Phylum Cnidaria - Coelente...

Explain Phylum Cnidaria - Coelenterates? Members of the Phylum Cnidaria and one other group-Phylum Ctenophora (the comb jellies)-are the only two animal phyla that have radiall

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