Human Biology Notes
BIO 202
Chapter 19: The Reproductive System
Section 19.1: Survival of the Species Depends on Gamete Formation
● Sexual reproduction requires two genders to perpetuate the species
○ Males contribute sperm
○ Females contribute eggs
○ Fertilization combines a sperm and an egg to produce the first cell of the new
individual (the zygote)
● Fertilization mixes and blends the alleles in the gene pool, creating new genetic
combinations, which leads to genetic variation
○ These new genetic combinations are essential to the survival of the species
The Reproductive System – Forming Gametes
● The main purpose of the reproductive system is to produce gametes (egg and sperm)
and unite them to form a new individual
● This involves choosing a mate based on phenotype and mixing and shuffling genes to
form a new individual
● This process blends the alleles in the gene pool giving new genetic combinations
● Gametes are produced through the process of meiosis
○ Meiosis is a specialized type of cell division that ensures the gametes will contain
the haploid chromosome number
■ Homologous chromosomes are separated one to each new gamete
Gametogenesis
● Spermatogenesis
○ In the male, meiosis is the process that forms four haploid sperm from two
nuclear divisions of a primary spermatocyte
○ Males produce about 300 million sperm per day from puberty until death
● •Oogenesis
○ In the female, meiosis is the process that forms one haploid egg and up to 3
haploid polar bodies
■ The haploid egg has the potential to be fertilized by one sperm
■ The polar bodies are not viable and are quickly degraded
● Females are born with all the eggs they will ever have
, The Reproductive System –
Other Functions
● Forming gametes is only one function of the reproductive system
● Other functions include
○ Triggering puberty
○ Maintaining reproductive ability
○ Stimulating secondary sex characteristics
○ Producing hormones involved in sexual maturation and general homeostasis
Section 19.2: The Male Reproductive System Produces, Stores, and Delivers Sperm
● There are three main functions of the male reproductive system
BIO 202
Chapter 19: The Reproductive System
Section 19.1: Survival of the Species Depends on Gamete Formation
● Sexual reproduction requires two genders to perpetuate the species
○ Males contribute sperm
○ Females contribute eggs
○ Fertilization combines a sperm and an egg to produce the first cell of the new
individual (the zygote)
● Fertilization mixes and blends the alleles in the gene pool, creating new genetic
combinations, which leads to genetic variation
○ These new genetic combinations are essential to the survival of the species
The Reproductive System – Forming Gametes
● The main purpose of the reproductive system is to produce gametes (egg and sperm)
and unite them to form a new individual
● This involves choosing a mate based on phenotype and mixing and shuffling genes to
form a new individual
● This process blends the alleles in the gene pool giving new genetic combinations
● Gametes are produced through the process of meiosis
○ Meiosis is a specialized type of cell division that ensures the gametes will contain
the haploid chromosome number
■ Homologous chromosomes are separated one to each new gamete
Gametogenesis
● Spermatogenesis
○ In the male, meiosis is the process that forms four haploid sperm from two
nuclear divisions of a primary spermatocyte
○ Males produce about 300 million sperm per day from puberty until death
● •Oogenesis
○ In the female, meiosis is the process that forms one haploid egg and up to 3
haploid polar bodies
■ The haploid egg has the potential to be fertilized by one sperm
■ The polar bodies are not viable and are quickly degraded
● Females are born with all the eggs they will ever have
, The Reproductive System –
Other Functions
● Forming gametes is only one function of the reproductive system
● Other functions include
○ Triggering puberty
○ Maintaining reproductive ability
○ Stimulating secondary sex characteristics
○ Producing hormones involved in sexual maturation and general homeostasis
Section 19.2: The Male Reproductive System Produces, Stores, and Delivers Sperm
● There are three main functions of the male reproductive system
