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

How public perception of science has distorted, Give an example of how the ...

Give an example of how the public perception of science has been distorted or manipulated to serve an alternative purpose.

Classification of the river zones, Classification of the river zones ...

Classification of the river zones The course of a river can be classified in two ways Firstly by its physical characteristics and Secondly by the presence or absen

Explain kingdom plantae, Kingdom Plantae The kingdom plant are includes m...

Kingdom Plantae The kingdom plant are includes multicellular eukaryote organisation with photosynthetic nutrition. Typically cell has cellulose wall, sap vacuole, plastids and .

#titleclasses of fish.., what are the two main classes into which fish are ...

what are the two main classes into which fish are divided

Explain a reason these cells are used instead of outer body, The cells lini...

The cells lining the inside of the cheek are frequently removed for making observations of basic cell structure. The cells are from stratified squamous epithelium. Explain a reason

A haploid cell attempted to perform meiosis, What problem would most likely...

What problem would most likely to occur if a haploid cell attempted to perform meiosis? The cell could not replicate its DNA prior to meiosis.The cell could not pair homologous

Tricuspid stenosis-tricuspid valve disease, Tricuspid Stenosis :  Acquired...

Tricuspid Stenosis :  Acquired tricuspid stenosis is most often due to chronic rheumatic carditis. Rarely could it be due to right atrial tumors or carcinoid syndrome producing mi

Explain therapeutic diet planning, Explain therapeutic diet planning Al...

Explain therapeutic diet planning All detailed dietary modifications  should be presented with choices,  clear guidelines, menu guidance and supporting  information  as  to  al

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