Causes of apomixis, Biology

Assignment Help:

Causes of Apomixis

Apomictic species are generally hybrids or polyploids, as a consequence, there is irregular meiosis. Apomixis appears to be controlled by a set of genes. The trait is genetically inherited. The genes controlling sexual reproduction are non-allelic to those of apomixis. Accordingly, any line of dissent carrying the genes for apomixis will produce both types, apomicts as well as sexually reproducing plants. It has been proposed that apomixis is governed by recessive genes. The three genes (AABBCC) determine the breeding behavior.

In homozygous condition a forms unreduced eggs, b prevents fertilization, and c promotes egg development without fertilization. Thus, aaBBCC will have unreduced egg but cannot develop without fertilization, AAbbCC produces reduced egg but no embryo development take place because fertilization is prevented, and AABBcc will show normal sexual behaviour because the gene C has no effect in the presence of A and B. As a consequence of apomixis, genetic variability in such species is frozen as they have the same genotypes as parents. However, facultative apomicts have an advantage as they have retained both kinds of reproduction.


Related Discussions:- Causes of apomixis

Describe microtubular cytoskeleton in protozoans, Protozoans have endoskele...

Protozoans have endoskeletons formed from microtubular cytoskeleton of the exoskeletons or cytoplasm secreted as shells or tests. Some of these single-cell organisms are capable of

How many asymmetric the amino acid serine have, How many asymmetric carbons...

How many asymmetric carbons does the amino acid serine have? Please explain with a strucutral diagram if possible.

Define direct measurement of individual''s work capacity, Define Direct mea...

Define Direct measurement of individual's Work Capacity? Direct measurement of VO 2 max is determined by having the subject perform exercise at increased loads, for 12 to 15 m

Methods of filter feeding, Methods of Filter Feeding More elaborate me...

Methods of Filter Feeding More elaborate methods of filter feeding are seen in tube dwelling polychaetes which use tentacles to entangle the food particles. Figure shows some

Functions of protein, FUNCTION S OF PROTEIN Proteins from the collo...

FUNCTION S OF PROTEIN Proteins from the colloidal complex of the protoplasm and its organelles. Most Abundant Protein in Organic World is RUBISCO or Ribulose biphosp

Show the natural selection of taxonomist, Q. Show the Natural selection of ...

Q. Show the Natural selection of taxonomist? Natural selection associated with successful reproduction maintains a basic similarity of the reproductive feature of flowers, frui

List out the different preservation techniques, List out the Different Pres...

List out the Different Preservation Techniques? The different preservation techniques commonly used today are given in the Table. Table: Methods of food preservation a)

Define precautions for preparation of phosphate buffers, Define Precautions...

Define Precautions for Preparation of Phosphate Buffers? 1. Glass electrodes should always be dried before and after measuring pH with a tissue paper. 2. The pipettes should

Which kind of gamete produced by a heterozygous individual, Which is the ki...

Which is the kind of gamete produced by a heterozygous individual? And what is the genotypical proportion of these gametes? The Heterozygous individuals, for instance, AA, prod

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