Stigma (anatomy): Difference between revisions

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'''Stigma (anatomy)''' refers to a small spot, mark, or pore that is significant in the anatomy of various organisms. In the context of anatomy, the term is most commonly associated with the respiratory system of insects and the reproductive system of plants. This article will focus on these two primary contexts, providing an overview of the role and function of stigmas in both insects and plants.
{{Short description|Anatomical structure in flowers}}
{{Anatomy}}


==In Insects==
==Stigma (anatomy)==
In insects, the '''stigma''' is an external opening of the [[tracheal system]], serving as a critical component in the insect's respiratory system. These openings, also known as spiracles, are located along the sides of the body and allow for gas exchange. Oxygen enters the tracheal system through these stigmas, while carbon dioxide is expelled. The regulation of these openings is crucial for the insect's survival, as it helps maintain the proper oxygen and carbon dioxide levels within their bodies.
The '''stigma''' is a vital part of the female reproductive system in [[flowering plants]]. It is the topmost part of the [[pistil]], which is the female reproductive organ of a flower. The stigma plays a crucial role in the process of [[pollination]] and [[fertilization]].


==In Plants==
[[File:Ovulation.jpg|thumb|right|Diagram of a flower showing the stigma as part of the pistil.]]
In the context of plant anatomy, a '''stigma''' is part of the [[pistil]], the female reproductive organ of a flower. It is the receptive tip of the pistil, where pollen lands and germinates. The stigma is often sticky or feathery, adapting to efficiently capture and trap pollen grains. Once pollen grains land on the stigma, they germinate, growing a pollen tube down the [[style]] to reach the [[ovary]], where fertilization occurs. The structure and function of the stigma are critical for plant reproduction, influencing the efficiency of pollen capture and the success of fertilization.


==Function and Significance==
==Structure==
The function and significance of the stigma vary significantly between insects and plants, yet in both cases, they play a crucial role in the survival and reproduction of the organism. In insects, the stigma's role in respiration is vital for metabolic processes, while in plants, the stigma is essential for reproduction and the continuation of species.
The stigma is typically located at the tip of the [[style]], which is a slender stalk that connects the stigma to the [[ovary]] of the flower. The stigma is often sticky or feathery, which helps it to effectively capture and hold [[pollen]] grains. The surface of the stigma can vary greatly among different species of plants, adapting to the specific pollination mechanisms they employ.


==See Also==
==Function==
* [[Tracheal system]]
The primary function of the stigma is to receive pollen during the process of pollination. Once pollen grains land on the stigma, they germinate and form a [[pollen tube]] that grows down the style to reach the ovary. This allows the sperm cells within the pollen to travel to the ovule, where fertilization occurs, leading to the formation of seeds.
 
==Pollination==
Pollination can occur through various means, including [[wind pollination]], [[insect pollination]], and [[animal pollination]]. The structure and position of the stigma are often adapted to the specific method of pollination. For example, in wind-pollinated plants, the stigma may be large and feathery to catch airborne pollen, while in insect-pollinated plants, it may be sticky to adhere to pollen carried by visiting insects.
 
==Variations==
Stigmas can vary widely in shape, size, and texture. Some stigmas are simple and flat, while others may be lobed or branched. The diversity in stigma morphology is often related to the plant's reproductive strategy and the type of pollinators it attracts.
 
==Related pages==
* [[Pistil]]
* [[Pistil]]
* [[Pollination]]
* [[Pollination]]
* [[Respiratory system]]
* [[Ovule]]
* [[Flower]]
* [[Reproductive system of plants]]


[[Category:Anatomy]]
[[Category:Plant anatomy]]
[[Category:Plant anatomy]]
[[Category:Insect anatomy]]
[[Category:Reproductive system]]
 
{{anatomy-stub}}

Latest revision as of 10:46, 15 February 2025

Anatomical structure in flowers


Stigma (anatomy)[edit]

The stigma is a vital part of the female reproductive system in flowering plants. It is the topmost part of the pistil, which is the female reproductive organ of a flower. The stigma plays a crucial role in the process of pollination and fertilization.

Diagram of a flower showing the stigma as part of the pistil.

Structure[edit]

The stigma is typically located at the tip of the style, which is a slender stalk that connects the stigma to the ovary of the flower. The stigma is often sticky or feathery, which helps it to effectively capture and hold pollen grains. The surface of the stigma can vary greatly among different species of plants, adapting to the specific pollination mechanisms they employ.

Function[edit]

The primary function of the stigma is to receive pollen during the process of pollination. Once pollen grains land on the stigma, they germinate and form a pollen tube that grows down the style to reach the ovary. This allows the sperm cells within the pollen to travel to the ovule, where fertilization occurs, leading to the formation of seeds.

Pollination[edit]

Pollination can occur through various means, including wind pollination, insect pollination, and animal pollination. The structure and position of the stigma are often adapted to the specific method of pollination. For example, in wind-pollinated plants, the stigma may be large and feathery to catch airborne pollen, while in insect-pollinated plants, it may be sticky to adhere to pollen carried by visiting insects.

Variations[edit]

Stigmas can vary widely in shape, size, and texture. Some stigmas are simple and flat, while others may be lobed or branched. The diversity in stigma morphology is often related to the plant's reproductive strategy and the type of pollinators it attracts.

Related pages[edit]