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

Do progeny shows all of the dominant phenotypes, Individuals of the followi...

Individuals of the following genotype are crossed: aa BB Cc Dd (crossed with) Aa Bb Cc Dd A) How many different phenotypes are possible for the progeny? B) What are the chanc

Clinical manifestation and diagnosis of pericardiocentesis, Clinical Manife...

Clinical Manifestation Occurs over an extended time period and mimic those of CHF and corpulmonale. Dyspnea on exertion, dependent odema, ascitis, fatigue, anorexia and weight

Describe the working of golgi bodies, Define in brief about the Golgi bodie...

Define in brief about the Golgi bodies In a cell is achieved in a remarkable fashion by the Golgi bodies. The latter receive the newly synthesised proteins from the rough endop

Determine about the disease - brain tumor, Determine about the disease - br...

Determine about the disease - brain tumor Tumor, or neoplasm, is a mass of new tissue that persists and grows independently of its surrounding structures and has no physiologic

Bacterial diseases-brucellosis, Brucellosis Brucellosis among cattle, ...

Brucellosis Brucellosis among cattle, buffaloes, sheep, goats, pigs produces heavy economic losses due to abortions in late pregnancy, infertility and reduction in productivit

Define water as a temperature regulator, Define Water as a temperature regu...

Define Water as a temperature regulator? Water plays an important role in the distribution of heat throughout the body and the regulation of body temperature. Heat is generate

How do bacteria reproduce, How do bacteria reproduce? Bacteria replicat...

How do bacteria reproduce? Bacteria replicate by binary fission (scissiparity). Some bacteria though present a kind of sexual reproduction (transformation, transduction or conj

Show the communication process steps, Q. Show the Communication process ste...

Q. Show the Communication process steps? Planning - Set goals. - Make a plan with alternatives. - Allow the counsellee to select a alternative which is feasible.

Explain in brief about unicellular “animals”, Single-cell organisms, protis...

Single-cell organisms, protists, have always been a problem for taxonomists who have trouble describing categories for organisms. Their mixed feeding habits that include being capa

Post-operative nursing care of a child with cleft lip, Post-operative Care ...

Post-operative Care   The goals of care during post-operative period include:  Prevent the baby from sucking and crying to avoid tension on suture line.  Give proper p

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