Fertilization and Gametes Overview

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Questions and Answers

What is the primary purpose of the sperm's acrosome?

To assist in the penetration of the oocyte (correct)

To store excess DNA

To protect the sperm from acidic environments

To provide energy for movement

How long can sperm survive inside the female reproductive tract?

1 week

48 hours

72 hours (correct)

24 hours

Where does fertilization mainly occur in the female reproductive system?

In the uterus

In the vagina

In the ampulla of the oviduct (correct)

In the cervix

What happens to the secondary oocyte if fertilization does not occur?

It degrades and is absorbed by the uterus Signup and view all the answers

What is the structure of the sperm's head primarily composed of?

Nucleus and acrosome Signup and view all the answers

Which component of the sperm provides the necessary energy for its movement?

Midpiece Signup and view all the answers

What is the approximate length of a sperm's head?

3–5 µm Signup and view all the answers

Which of the following statements is true regarding the sperm's DNA structure?

It is concentrated in the smallest volume possible Signup and view all the answers

What structures surround the axial filament in sperm?

Fibrils with circular layout Signup and view all the answers

Which component does NOT contribute to the energy supply in sperm?

Ribosomes Signup and view all the answers

Which statement about oocyte mitochondria is correct?

They contain one to two copies of mitochondrial DNA each. Signup and view all the answers

What is the primary function of the tail in sperm?

To enable motility Signup and view all the answers

What is a key characteristic of the germinal vesicle found in oocytes?

It is highly transcriptionally active. Signup and view all the answers

During which process do sperm undergo biochemical changes in the female reproductive tract?

Capacitation Signup and view all the answers

Which factor helps to guide sperm towards the zona pellucida?

Chemical signals released by the oocyte Signup and view all the answers

What is the result of the changes that occur in sperm during capacitation?

Preparation for acrosome reaction Signup and view all the answers

What is the primary role of cholesterol removal during sperm capacitation?

It increases membrane fluidity and permeability. Signup and view all the answers

What is the primary purpose of the cortical reaction in fertilization?

To prevent additional sperm from binding to the oocyte Signup and view all the answers

Which enzyme is activated by calcium and bicarbonate ions during the sperm's capacitation?

Adenylate cyclase Signup and view all the answers

Which glycoprotein on the zona pellucida interacts with sperm to initiate the acrosome reaction?

ZP3 Signup and view all the answers

What triggers the completion of the second meiotic division in the oocyte?

Calcium ion waves triggered by sperm entry Signup and view all the answers

What results from the completion of meiosis in the oocyte?

Expulsion of the second polar body Signup and view all the answers

What is the function of enzymes released during the acrosome reaction?

To degrade the zona pellucida structure. Signup and view all the answers

What marks the beginning of a new individual’s genetic information during fertilization?

Fusion of the sperm and oocyte pronuclei Signup and view all the answers

What is the role of IZUMO1 protein on the sperm?

To facilitate the fusion with the oocyte membrane. Signup and view all the answers

Which process helps ensure that only one sperm fertilizes the oocyte?

Cortical reaction Signup and view all the answers

What happens to the membranes of the sperm and oocyte during fertilization?

They merge to allow sperm entry. Signup and view all the answers

What role do calcium waves play shortly after sperm entry into the oocyte?

Triggering completion of meiosis Signup and view all the answers

What mechanism prevents polyspermy during fertilization?

Cortical reaction of the oocyte. Signup and view all the answers

What happens immediately after the fusion of the sperm and oocyte plasma membranes?

Zona pellucida hardens Signup and view all the answers

Which of the following statements about the zona pellucida is correct?

It is comprised of ZP1, ZP2, and ZP3 glycoproteins. Signup and view all the answers

Which protein interaction is crucial for the fusion of sperm and oocyte during fertilization?

IZUMO1 and JUNO Signup and view all the answers

Study Notes

Fertilization

Fertilization is the fusion of the male and female gametes, resulting in a diploid zygote.
The zygote is the single cell from which a new individual organism develops.
Fertilization occurs in the ampulla of the oviduct.

Sperm - The Male Gamete

Sperm consists of three parts: a head, a midpiece, and a tail.
The head contains DNA and enzymes necessary for penetrating the oocyte.
The midpiece contains mitochondria for energy production.
The tail enables sperm movement.

Oocyte - The Female Gamete

The oocyte is a large cell with a large, active nucleus.
It is rich in cytoplasm and contains numerous organelles and proteins.
The oocyte is also filled with mitochondria, vital for energy production during development.

Sperm-Oocyte Encounter

The oocyte releases chemical signals, like progesterone, that attract sperm.
This process is called chemotaxis.
Temperature differences in the fallopian tubes also influence sperm movement, known as thermotaxis.

Sperm Capacitation

Capacitation is a maturation process that sperm undergo in the female reproductive tract.
The sperm plasma membrane changes during capacitation.
These changes increase sperm motility, making it capable of penetrating the oocyte's plasma membrane.

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Description

This quiz covers the process of fertilization, the structure of sperm and oocyte, and their roles in reproduction. Learn about the chemical signals that facilitate sperm movement towards the oocyte and the significance of each gamete. Test your understanding of these fundamental biological concepts.