Problem 134 - Objective Biology for NEET

Question

The male and female sex organs of pteridophyte are called (a) Globule and nucule respectively (b) Antheridia and archegonia respectively (c) Spermatangia and oogonia respectively (d) Tests and ovary respectively

Step-by-Step Solution

Answer

The correct answer is (b) Antheridia and archegonia respectively.

Step 1: Understanding the question

First, understand that the question is asking for the names of the male and female sex organs in pteridophytes, which are a type of non-flowering plant.

Step 2: Analyzing the options

Next, we need to examine all the provided options. We should have a basic understanding of Botanical terms involved in plant reproduction.

Step 3: Selecting the correct option

Through the knowledge of Botany, we know that in pteridophytes, the male organ is called the antheridia and the female organ is called the archegonia. So the correct option is (b) Antheridia and archegonia respectively.

Key Concepts

Male Sex Organs

In the fascinating world of pteridophytes, the male sex organs are pivotal to the reproductive process. These organs play a critical role in the generation and dispersal of male gametes, which are necessary for the fertilization of female gametes and subsequent formation of a new plant.

Male sex organs in pteridophytes are known as **antheridia**. These structures are typically small and can often be found on the underside of the leaves or in certain reproductive specialized areas.

• Antheridia produce male gametes, also known as spermatozoids.
• These spermatozoids are mobile and swim using flagella.
• The movement towards the female sex organ is often facilitated by water, an essential component in their reproductive cycle.

Understanding the role of male sex organs helps in appreciating how non-flowering plants like pteridophytes reproduce without seeds.

Female Sex Organs

Pteridophytes also have specialized female sex organs, which are essential for sexual reproduction. These organs develop from specific tissues and are responsible for harboring the female gamete.

The female sex organs are called **archegonia**. They are structures that serve as the site for fertilization and play a crucial part in housing and nurturing the developing embryo.

• Archegonia are typically flask-shaped structures.
• They consist of a neck and a swollen base known as the venter.
• The venter contains the egg cell, which is the female gamete.

After fertilization, the archegonia support the early stages of sporophyte development, ensuring a successful continuation of the species.

Antheridia

Antheridia are the male gametangia in pteridophytes. These structures form on the gametophyte, the sexual stage in the life cycle of these plants. The active role of antheridia in reproduction highlights their significance.

Typically, each antheridium contains multiple sperms, ready to be released upon maturation. Here's a closer look at how antheridia function:

• Once mature, the antheridia burst open to release sperm cells.
• This release is usually triggered by environmental cues such as moisture.
• The sperm cells are motile and seek out the archegonia in their watery environment.

The design and function of antheridia emphasize efficiency in ensuring the transport and fusion of gametes needed for successful fertilization.

Archegonia

Archegonia are the female gametangia, instrumental in the reproduction of pteridophytes. Located on the gametophyte, archegonia ensure the protection and nutrition of the plant embryo after fertilization.

Archegonia have a unique structure to fulfill their role effectively:

• The neck of the archegonia helps direct sperm to the egg cell.
• Upon successful fertilization, the zygote remains within the protective structure of the archegonia.
• This structure provides nourishment as the zygote develops into a young sporophyte.

The strategic positioning and design of archegonia underscore the importance of this organ in plant reproduction and survival in diverse environments.