Types of embryogeny, Biology

Types of Embryogeny

On the basis of the plane of division of the zygote and of the cells of the 2-celled proembryo, and also taking into account the relative contributions of the cells of the 4-celled proembryo to the mature embryo, six chief types of Embryogeny have been recognized.

A. Division of the zygote is vertical - Piperade type (e.g. Loranthaceae, Piperaceae).

AA. Division of the zygote is transverse.

B. Apical cell of the 2-celled proembryo divides vertically to form a T-shaped, 4-celled proembryo.

C. Basal cell plays no role at all or only an insignificant role in subsequent development of the proembryo-(Crucifer or Onagrad type (e.g., Ranunculaceae, Brassicaceae).

CC. Basal cell and apical cell both contribute to the development of the embryo - Asterad type (e.g., Asteraceae, Violaceae).

BB. Apical cell of 2- celled proembryo divides transversely so that the 4-celled proembryo is usually linear.

D. Basal cell does not participate or only contributes a little to development of embryo proper.

E. Basal cell usually forms a suspensor - Solanad type (e.g., Solanaceae, Linaceae).

EE. Basal does not divide further and the suspensor, if present, is derived from the apical cell - Caryophyllata type (e.g., Caryophyllaceae, Crassulaceae).

DD. Basal cell and apical cell both divide and contribute to formation of the embryo - Chenopodium type (Chenopodiaceae, Boraginaceae).

Posted Date: 1/23/2013 7:23:52 AM | Location : United States







Related Discussions:- Types of embryogeny, Assignment Help, Ask Question on Types of embryogeny, Get Answer, Expert's Help, Types of embryogeny Discussions

Write discussion on Types of embryogeny
Your posts are moderated
Related Questions
Q. Basis of Classification on Form-relationship principle? As pointed out earlier, this system is mainly based on Form-relationship principle. thus the various genera were. g

notes on urea

If a cow develops a preference for eating white four o'clock flowers and ignoring pink and red four o'clock flowers, what type of selection is being demonstrated? Would the cow eve

What is plant coleoptile? Why does the removal of the coleoptile extremity disallow plant growth? Coleoptile is first (one or more) aerial structure of the sprouting plant that

Explain carbohydrates requirement during thyphoid Carbohydrates: Carbohydrate intake should be liberal. This can be attributed  to: 1.  Repletion of glycogen stores. 2.

Define the Role of Vitamin A in immune response? Vitamins A is essential to normal immune function and- regulation. As discussed above, during vitamin A deficiency the goblet c


Q. Do echinoderms have circulatory and respiratory systems? In echinoderms there are not well- defined respiratory with the exception of the holothurian group and circulatory s

What are the Amylase Inhibitors? Inhibitors of the enzyme a-amylase are found in wheat, rye, beans, mango, legumes, potatoes, sorghum (jowar) and oats. Most amylase inhibitors

Galvanotaxis - Modes of Cell Movement Galvanotaxis considers to the movement of cells in response to a potential variation between cells. It is suggested that there are voltag