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

What is the function of the immune system, What is the function of the immu...

What is the function of the immune system? The immune system performs exact defense against agents, the antigens, that are foreign or harmful to the body. Exogenous antigens

Pulmonary arterial system changes, Q. Pulmonary Arterial System Changes ? ...

Q. Pulmonary Arterial System Changes ? a) Pulmonary Plethora With increased pulmonary arterial blood flow, pulmonary branches are visualized beyond the inner 2/3 of the lung

Which technique would use to see if a particular protein, Which technique w...

Which technique would you use to A) see if a particular protein bound to a piece of DNA B) Detect exactly where on a piece of DNA a protein bound.

Define utilization of soy protein concentrate, Define Utilization of Soy Pr...

Define Utilization of Soy Protein Concentrate? Soy protein concentrates are used in food products for their nutritional characteristics or for their functional properties or fo

What are the signs used in acute pericarditis, Q. What are the Signs used i...

Q. What are the Signs used in acute pericarditis? • Pericardial friction rub is pathognomonic of pericarditis. It is heard as a phasic scatching sound. It may vary with phases

Proestrus - estrous cycle, Proestrus - Estrous cycle This precedes the...

Proestrus - Estrous cycle This precedes the next heat and is characterised by functional involution of the corpora lutea and preovulatory swelling of the follicles. Fluid coll

Role of dietitian in health care, Role of Dietitian in Health Care The ...

Role of Dietitian in Health Care The role of the dietitian has come a long way since the early 1900s. Their role is still unknown to a  lot of people. Some think that dietitian

Define type of instruments used in spectral techniques, Define Type of Inst...

Define Type of Instruments used in Spectral Techniques? A wide range of instruments are available, possessing a combination of features but there is no rigid classification of

Identify by mean of biochemical tests, The human blood group, related to th...

The human blood group, related to the MN system is controlled by two alleles, S and s. Three distinct phenotypes can be identified by mean of biochemical tests. Among 1000 Britishe

What is rounded st depression, Q. What is Rounded ST Depression? A roun...

Q. What is Rounded ST Depression? A rounded ST-segment depression pattern in the CM5 lead, as well as in the other leads, is common and is often associated with ischaemia. This

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