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

What are classes into which the phylum arthropoda is divide, Q. What are th...

Q. What are the classes into which the phylum Arthropoda is divided? What are the three major ones and some of their representative species? The three main classes of arthropod

Rna editing, RNA  editing  is  the  name  given  to  several  reactions  wh...

RNA  editing  is  the  name  given  to  several  reactions  whereby  the  nucleotide series  on an mRNA  molecule  should  be modified  by mechanisms  other  than RNA  splicing.  T

Explain pedicellaria in brief, Explain Pedicellaria in brief? Defensive...

Explain Pedicellaria in brief? Defensive pincerlike structures found on the surface of echinoderms. They are capable of responding to external stimuli independently from the ma

01.03 new technology, What is the best microscope to get a detailed view of...

What is the best microscope to get a detailed view of the parts inside of a preserved plant cell?

What is the function of the testicles, Q. Concerning reproduction what is t...

Q. Concerning reproduction what is the function of the testicles? The testicles are the male gonad that is the organs where the production of gametes takes place. In human bein

Energetic function of organic molecules, Q. What are the few examples of th...

Q. What are the few examples of the energetic function of organic molecules? Ans. Since they are complex molecules, organic molecules store large amount of energy, present

Secondary and tertiary consumers - biotic components, Secondary and Tertiar...

Secondary and Tertiary Consumers - Biotic Components Besides there are animals which depend on herbivores for food and are called secondary consumers. Since secondary consumer

Respiratory gases -respiration, Respiratory Gases -Respiration Physio...

Respiratory Gases -Respiration Physiologically the most important gases are oxygen, carbon dioxide and nitrogen. Molecular oxygen comprises 21% of the atmosphere; carbon diox

What are the preservation of insulin, What are the Preservation of Insulin ...

What are the Preservation of Insulin Regular insulin is stable for 18 months at 23.8 0 C and Lente insulin are stable for 24 months at this temperature. Although refrigeration

What is the significance of proteins for living beings, Q. What is the sign...

Q. What is the significance of proteins for living beings? Proteins play an essential role in nearly all biological processes. Due to their variety they can suppose many divers

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