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

Show the physical criteria of quality for honey, Q. Show the Physical crite...

Q. Show the Physical criteria of quality for Honey? Colour, crystallization, pH, acidity, water content are some of the criteria used for analysis of honey. These criteria are

Therapeutic dose of pyridoxine, Q. Therapeutic dose of pyridoxine? Ther...

Q. Therapeutic dose of pyridoxine? Therapeutic dose of pyridoxine (lg/day) is usually tried in all patients with hypermethioninernia and homocystinemia. For patients who do not

How rapidly a person breathes, Considering the nature of negative-feedback ...

Considering the nature of negative-feedback control and the function of the respiratory system, what effect do you predict that a decrease in CO2 in the internal environment would

Explain ganongs potometer, For measuring the rate of transpiration of a twi...

For measuring the rate of transpiration of a twig using Ganong's potometer, learner A cuts the twig and fits it in the broad end of the water-filled potometer. Learner B cuts the t

The cell, how does autophagy help in converting a tadpole larva into an adu...

how does autophagy help in converting a tadpole larva into an adult amphibian

Explain adverse effects of ritonavir, Explain Adverse effects of ritonavir ...

Explain Adverse effects of ritonavir - Adverse reactions are common to full doses of ritonavir, but less common with the low doses used in PI combinations. Ritonavir can cause

Water loss - plant water relation, Water Loss - Plant Water Relation ...

Water Loss - Plant Water Relation Plants lose about 98% of water to the atmosphere by transpiration. Often water loss by transpiration exceeds gain by absorption and results

Cytokinesis in an animal cell, Cytokinesis in an animal cell: Splitting...

Cytokinesis in an animal cell: Splitting of the cell is called cytokinesis which starts at telophase. In animal cells, microtubules form a furrow in a ring around the cell.

Determine the important neuropathic symptoms, The following are the importa...

The following are the important neuropathic symptoms: 1. Dysesthesia: It means burning or tingling sensation, sunburn like feeling etc. Take a note of duration, time of occurre

Define classification of weight imbalance, Define Classification of Weight ...

Define Classification of Weight Imbalance? Obesity is defined as a condition with accumulation of excess body fat. Do you think that a measure of how much fat a person has in i

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