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Annotate diagrams of mature sperm and egg cells to indicate their structure and function in fertilization.
Annotate diagrams of mature sperm and egg cells to indicate their structure and function in fertilization.
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To annotate diagrams of mature sperm and egg cells, we will highlight their structures and functions in the context of fertilization. Below is a detailed description of each component along with its role in the fertilization process.
Annotated Diagram of Mature Sperm Cell
- Head:
- Description: Contains the nucleus, which houses the haploid set of chromosomes (23 chromosomes).
- Function: The genetic material from the male is delivered to the egg during fertilization.
- Acrosome:
- Description: A cap-like structure covering the anterior part of the sperm head, filled with enzymes.
- Function: Contains hydrolytic enzymes that facilitate the penetration of the zona pellucida (the outer layer of the egg) during fertilization by digesting this protective barrier.
- Midpiece:
- Description: Contains tightly packed mitochondria wrapped around the axial filament.
- Function: Provides the energy required for sperm motility through ATP production, powering the movement of the tail.
- Tail (Flagellum):
- Description: A long, whip-like structure extending from the midpiece.
- Function: Propels the sperm forward, allowing it to swim through the female reproductive tract to reach the egg.
- Neck:
- Description: The region connecting the head and midpiece.
- Function: Contains centrioles that are important for initiating the first cleavage division of the egg after fertilization.
Annotated Diagram of Egg Cell (Ovum)
- Cytoplasm (Yolk):
- Description: The bulk of the egg cell, rich in nutrients.
- Function: Provides essential nutrients for early embryonic development before implantation occurs.
- Nucleus:
- Description: Contains a haploid set of chromosomes (23 chromosomes).
- Function: Carries genetic material from the female that combines with that from the sperm during fertilization to form a diploid zygote.
- Zona Pellucida:
- Description: A thick, glycoprotein layer surrounding the egg.
- Function: Acts as a protective barrier and plays a crucial role in sperm binding and preventing polyspermy by undergoing changes after fertilization.
- Corona Radiata:
- Description: A layer of follicular cells surrounding the zona pellucida.
- Function: Provides support and nourishment to the egg; also involved in signaling processes that attract sperm to the egg.
- Cortical Granules:
- Description: Small vesicles located just beneath the plasma membrane of the egg.
- Function: Release enzymes during fertilization that modify the zona pellucida to prevent additional sperm from binding (cortical reaction), thus ensuring that only one sperm fertilizes the egg.
Summary Table
| Structure | Location | Description/Function |
|---|---|---|
| Head | Anterior part of sperm | Contains haploid nucleus; delivers genetic material during fertilization |
| Acrosome | Cap on sperm head | Contains enzymes to penetrate zona pellucida |
| Midpiece | Between head and tail | Packed with mitochondria; provides energy for motility |
| Tail (Flagellum) | Posterior part of sperm | Propels sperm forward through swimming motion |
| Neck | Connects head and midpiece | Contains centrioles; important for initiating cleavage division |
| Cytoplasm (Yolk) | Inside ovum | Rich in nutrients for early embryo development |
| Nucleus | Center of ovum | Contains haploid chromosomes; combines with sperm’s genetic material |
| Zona Pellucida | Surrounding ovum | Protective layer; involved in sperm binding and preventing polyspermy |
| Corona Radiata | Outside zona pellucida | Layer of follicular cells providing support and nourishment |
| Cortical Granules | Beneath plasma membrane | Release enzymes to modify zona pellucida after fertilization, preventing polyspermy |
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