Conception and Multiple Births

Study Notes

Conception/Fertilization

Conception occurs when a sperm successfully penetrates an egg cell, resulting in fertilization.
Key factors for successful conception include:
- Release of one healthy egg from the ovaries.
- Migration of the egg cell towards the fallopian tube.
- Penetration of the egg by a single sperm to form a zygote.

Multiple Births

Dizygotic twins, also known as fraternal twins, form from two different sperm and egg cells, resulting in different genetic makeups akin to regular siblings.
Monozygotic twins, or identical twins, originate from a single fertilized ovum that splits, leading to identical genetic makeup.
Factors contributing to multiple births include:
- Delayed childbearing, which increases the likelihood of multiple ovulations.
- The increased use of fertility treatments, including fertility drugs.
- Procedures like in vitro fertilization (IVF) that often involve the transfer of multiple embryos.

Mechanisms of Heredity

DNA (deoxyribonucleic acid) serves as the fundamental basis for heredity.
The genetic code is determined by the sequence of base pairs within the DNA.
The complete set of DNA sequences is referred to as the human genome.
Genes are small segments of DNA that encode specific traits.
Each cell contains chromosomes, which are tightly coiled structures of DNA that carry genetic information.

Description

This quiz covers the basics of conception, focusing on how a sperm fertilizes an egg and the conditions required for successful conception. Additionally, it explores the differences between dizygotic and monozygotic twins, providing insights into multiple births and their genetic implications.