Types of ovules, Biology

Assignment Help:

Types of Ovules

Anatropous

This is the most common type of ovule in angiosperms in which the ovule undergoes curvature such that the micropylar end comes to lie parallel to the funiculus.

Orthotropous

In this type of ovule no curvature occurs and the micropyle lies in a straight line with respect to the funiculus.

Hemi anatropous

The hemi anatropous condition results from the curvature of the ovule such that the micropyle comes to lie at right angles to the funiculus.

Campylotropous

In campylotropous type, the ovule is curved but the curvature is less than that in the anatropous condition.

Amphitropous

The amphitropous ovule looks like the campylotropous ovule at the first glance. But there is a point of distinction. In this type the nucellus and the embryo sac are curved like a horse shoe.

Circinotropous

Besides the above basic forms, another interesting type that you should know is the circinotropous ovule. In the early developmental stages of such ovules the .nucellar protuberance is more or less in line with the axis. In the further developmental stages, due to unilateral growth, it assumes anatropous form. The curvature does not stop at this, but continues until the ovule has turned over completely so that the micropylar end again points upwards. This kind of ovule is common in families Cactaceae and Plumbaginaceae.


Related Discussions:- Types of ovules

Explain vitamin B complex, Vitamin B Complex The vitamin B complex comp...

Vitamin B Complex The vitamin B complex comprises the vitamins B 1 , B 2 , B 6 and B 12 as well as the vitamin B factors biotin, folic acid, nicotinic acid and its amide as w

What is phenotypical proportion, Considering hybridization in a given trait...

Considering hybridization in a given trait like the color of the hair of a mammalian species (white/black) conditioned by a pair of different alleles under complete dominance (blac

Crustose lichen stage - xerarch, Crustose Lichen Stage - Xerarch On ba...

Crustose Lichen Stage - Xerarch On bare rocks, conditions are inhospitable for life, as there is extreme deficiency of water and nutrients, great exposure to sun, and extremes

Explain about pentoses, What are pentoses? To what organic group do pentose...

What are pentoses? To what organic group do pentoses belong? Are nucleotides formed of only one type of pentose? Pentoses are carbohydrates made of five carbons. Deoxyribose is

What is the essential morphology of a protozoan cell, Q. What is the essent...

Q. What is the essential morphology of a protozoan cell? Protozoans are eukaryotic cells so they have structures and organelles common to this kind of cell endoplasmic reticula

Objectives of gingival curettage - endodontic surgery, Objectives of Gingiv...

Objectives of Gingival Curettage - Endodontic Surgery a) Provides access and visibility of the apex, b) Removal inflamed tissues, c) Provides biopsy. -  It’s advisable

Homework, Which of the following is NOT a process that may provide an adapt...

Which of the following is NOT a process that may provide an adaptive advantage to eukaryotic chromosomes?.tion..

Discuss about smooth muscles, Smooth muscles These muscles are beyond o...

Smooth muscles These muscles are beyond our control. That means these muscles are controlled by autonomic nervous system. They are non-voluntary muscles. They are found in thin

What are the symptom of short bowel syndrome, Q. What are the Symptom of sh...

Q. What are the Symptom of short bowel syndrome? Diarrhoea is the main symptom of short bowel syndrome. Other symptoms include: • Anorexia • Steatorrhoea • Heart bum a

Birth marks (naevi) and vascular naevi, Birth Marks  (Naevi): Birth Ma...

Birth Marks  (Naevi): Birth Marks  is also known  as naevi.  It  is a multiplication  of  one or more cutaneous elements within  the skin. It  is defined  as a  congenital, ci

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