Question

The correct sequence of developmental stages of embryo in angiosperms is ___________.

• A. Octant $\rightarrow$ globular $\rightarrow$ heart shaped $\rightarrow$ horse shoe shaped
• B. Globular $\rightarrow$ octant $\rightarrow$ heart shaped $\rightarrow$ horse shoe shaped
• C. Octant $\rightarrow$ heart shaped $\rightarrow$ horse shoe shaped $\rightarrow$ globular
• D. Octant $\rightarrow$ horse shoe shaped $\rightarrow$ heart shaped $\rightarrow$ globular

Hint:

Always remember: globular stage comes before heart-shaped stage in angiosperm embryo development.

Answer 1

The Correct Option is A

Step 1: Understanding embryonic development in angiosperms.
After fertilization, the zygote undergoes a series of mitotic divisions forming a multicellular embryo with distinct morphological stages.
Step 2: Order of developmental stages.
The embryo first reaches the octant stage, followed by the globular stage. With differentiation of cotyledons, it becomes heart shaped, and later develops into the horse shoe shaped stage.
Step 3: Analysis of options.
(A) Correct — this sequence accurately represents embryo development in angiosperms.
(B), (C), (D) Incorrect — these do not follow the correct developmental progression.
Step 4: Conclusion.
The correct sequence is octant $\rightarrow$ globular $\rightarrow$ heart shaped $\rightarrow$ horse shoe shaped.