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

Oxygen cycle, Oxygen is a major component of all living organisms. All the ...

Oxygen is a major component of all living organisms. All the organisms and plants required oxygen for aerobic respiration which they absorb from environment. Only plants release ox

Plasmotomy, draw a well labled diagram of plasmotomy

draw a well labled diagram of plasmotomy

How fats promote absorption of fat soluble vitamins, 1. Fats promote absorp...

1. Fats promote absorption of fat soluble vitamins like vitamin A, D, E and K. Patients of cystic fibrosis often absorb fat poorly and are at-risk for fat-soluble vitamin deficienc

How organic farming differ from traditional farming, Recently, the media ha...

Recently, the media have promoted the idea of consuming only locally grown, organic produce. Are there any nutritional values that might be present in locally grown produce that mi

Neurons, how does sodium and potassium ions maintain the resting petential ...

how does sodium and potassium ions maintain the resting petential of neurons

Explain the techniques of surgical correction , Explain  the Techniques of...

Explain  the Techniques of Surgical Correction ? Techniques of Surgical Correction proximal Dissection (De Bakey type I and IZ or Stanford A) Monitoring lines are insert

What are proteins and why they are important for us, What are Proteins and ...

What are Proteins and Why they are important for us? We just read that proteins are essential for maintaining and sustaining life. What are proteins or what constitutes protein

Explain procedure of aortic valvuloplasty, Q. Explain procedure of Aortic V...

Q. Explain procedure of Aortic Valvuloplasty? BAV is usually performed by the retrograde transarterial approach. Often another catheter is placed in the LV through transseptal

Explain the several terms atp, Explain the several terms ATP, NAD, and FAD ...

Explain the several terms ATP, NAD, and FAD ? Adenosine Triphosphate (ATP) is an ester, an organic compound formed from a reaction between carboxylic acid and an alcohol. ATP i

Section 3.1, Lack of iron in the photic zone of the ocean restricts the siz...

Lack of iron in the photic zone of the ocean restricts the size of plankton population.Iron is what kind of factor for marine plankton?

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