Podcast
Questions and Answers
Which of the following best describes the primary role of cervical mucus in fertilization?
Which of the following best describes the primary role of cervical mucus in fertilization?
What is the direct consequence of the acrosome reaction in fertilization?
What is the direct consequence of the acrosome reaction in fertilization?
What is the significance of the cortical reaction in the fertilization process?
What is the significance of the cortical reaction in the fertilization process?
What event directly leads to the formation of the female pronucleus?
What event directly leads to the formation of the female pronucleus?
Signup and view all the answers
Which process directly precedes the alignment of chromosomes on the equatorial plane during fertilization?
Which process directly precedes the alignment of chromosomes on the equatorial plane during fertilization?
Signup and view all the answers
What is the chromosomal composition of a zygote?
What is the chromosomal composition of a zygote?
Signup and view all the answers
Which of the following dictates the sex of the zygote?
Which of the following dictates the sex of the zygote?
Signup and view all the answers
What is the direct result of karyogamy in the fertilization process?
What is the direct result of karyogamy in the fertilization process?
Signup and view all the answers
Study Notes
Sperm Migration and Capacitation
- Sperm travel from the cervix to the fallopian tubes
- Cervical mucus aids migration by providing an alkaline medium
- Biochemical changes in sperm plasma membrane enable sperm binding to the zona pellucida
- Capacitation occurs in the female reproductive tract
Pre-Fertilization Phenomena
- Sperm reaches the outer third of the fallopian tube (ampulla)
- Sperm releases hyaluronidase to break down intercellular connections in the corona radiata
- Sperm binds to ZP3 glycoprotein receptors on the zona pellucida
- Acrosome reaction: Acrosome releases hydrolytic enzymes (e.g., acrosin) to digest the zona pellucida
- A single spermatozoon penetrates the zona pellucida and fuses with the oocyte plasma membrane
Cortical Reaction and Meiosis II
- Cortical reaction: Exocytosis of cortical granules alters the zona pellucida, preventing polyspermy
- Secondary oocyte completes meiosis II upon sperm penetration
- Second polar body extruded
Formation of Pronuclei
- Sperm nucleus becomes the male pronucleus
- Oocyte nucleus becomes the female pronucleus
- Pronuclei migrate towards the cell center
- Pronuclei membranes disintegrate
- Chromosomes align on the equatorial plane of the spindle apparatus
Karyogamy (Fusion of Pronuclei)
- Results in the formation of a zygote with 44 autosomes and 2 sex chromosomes
Zygote Formation
- Zygote is the first cell of the new organism
- Contains a complete diploid set of chromosomes
- Composed of combined male and female genetic contributions
Sex Determination
- Sperm's sex chromosome (X or Y) determines the sex of the zygote
- X-sperm: Female (XX)
- Y-sperm: Male (XY)
Outcomes
- Zygote initiates its first mitotic division (cleavage) forming blastomeres
- Embryonic development begins.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the journey of sperm from the cervix to the fallopian tubes, including key biochemical changes that enable fertilization. Explore essential processes like capacitation, acrosome reaction, and the cortical reaction that prevent polyspermy. Test your knowledge on these vital pre-fertilization phenomena in human reproduction.
