Comprehensive Human Development & Genetics
Exam Review: Fertilization, Capacitation,
Amphimixis, Cleavage, Blastocyst & Implantation,
Gastrulation & Germ Layers (Ectoderm, Mesoderm,
Endoderm), Placentation & Extraembryonic
Membranes, Trimester Development,
Organogenesis, Parturition & Labor Stages,
Multiple Births, Postnatal Growth & Puberty,
Senescence, Mendelian & Polygenic Inheritance,
Genetic Recombination, Mutation, Sex-Linked
Traits, Chromosomal Abnormalities, and Human
Genome Principles Exam Questions Veerified and
Provided with A+ Graded Rationales Latest
Updated 2026
Development
Gradual modification of anatomical structures & physiological characteristics from fertilization
to maturity
Inheritance
Transfer of genetic material from generation to generation
Differentiation
- Creation of different types of cells required in development
- Occurs through selective changes in genetic activity
--> As development proceeds, some genes are turned off, others are turned on
- Involves changes in genetic activity of some cells but not others
Fertilization (Conception)
When development begins
Embryonic Development
,- Occurs during first two months after fertilization
- Embryology: the study of these events
Fetal Development
- Begins at start of 9th week
- Continues until birth
Prenatal Development
Embryonic & fetal development stages
Postnatal Development
- Commences at birth
- Continues to maturity (the state of full development or completed growth
Genetics
The study of mechanisms responsible for inheritance
Fertilization
- Fusion of two haploid gametes each containing 23 chromosomes
- Produces zygote containing 46 chromosomes
- Occurs in uterine tube within a day after ovulation
--> Secondary oocyte travels a few centimeters
--> Spermatozoa must cover distance between vagina & ampulla
Spermatozoon
- Delivers paternal chromosomes to fertilization site
- Travels relatively large distance
- Small, efficient, & highly streamlined
Gamete
Provides:
- Cellular organelles
, - Inclusions
- Nourishment
- Genetic programming necessary to support development of embryo for a week
Capacitation
Changes of spermatozoa while in female
- Must occur before spermatozoa can fertilize secondary oocyte
--> Contract with secretions can fertilize secondary oocyte
--> Exposure to conditions in female reproductive tract
Hyaluronidase
- Enzyme breaks down bonds between adjacent follicle cells
- Allows spermatozoa to reach oocyte
Acrosin
- A proteolytic enzyme
- Required to reach oocyte
Acrosomes
- Release hyaluronidase & across
- Penetrate corona radiata, zona pellucida, toward oocyte surface
Oocyte Activation
- Contact and fusion of cell membranes of sperm and oocyte
- Follows fertilization
- Oocyte completes meiosis II, becomes mature ovum
Polyspermy
- Feriliztion by more than one sperm
- Prevented by cortical reaction
Cortical Reaction
Exam Review: Fertilization, Capacitation,
Amphimixis, Cleavage, Blastocyst & Implantation,
Gastrulation & Germ Layers (Ectoderm, Mesoderm,
Endoderm), Placentation & Extraembryonic
Membranes, Trimester Development,
Organogenesis, Parturition & Labor Stages,
Multiple Births, Postnatal Growth & Puberty,
Senescence, Mendelian & Polygenic Inheritance,
Genetic Recombination, Mutation, Sex-Linked
Traits, Chromosomal Abnormalities, and Human
Genome Principles Exam Questions Veerified and
Provided with A+ Graded Rationales Latest
Updated 2026
Development
Gradual modification of anatomical structures & physiological characteristics from fertilization
to maturity
Inheritance
Transfer of genetic material from generation to generation
Differentiation
- Creation of different types of cells required in development
- Occurs through selective changes in genetic activity
--> As development proceeds, some genes are turned off, others are turned on
- Involves changes in genetic activity of some cells but not others
Fertilization (Conception)
When development begins
Embryonic Development
,- Occurs during first two months after fertilization
- Embryology: the study of these events
Fetal Development
- Begins at start of 9th week
- Continues until birth
Prenatal Development
Embryonic & fetal development stages
Postnatal Development
- Commences at birth
- Continues to maturity (the state of full development or completed growth
Genetics
The study of mechanisms responsible for inheritance
Fertilization
- Fusion of two haploid gametes each containing 23 chromosomes
- Produces zygote containing 46 chromosomes
- Occurs in uterine tube within a day after ovulation
--> Secondary oocyte travels a few centimeters
--> Spermatozoa must cover distance between vagina & ampulla
Spermatozoon
- Delivers paternal chromosomes to fertilization site
- Travels relatively large distance
- Small, efficient, & highly streamlined
Gamete
Provides:
- Cellular organelles
, - Inclusions
- Nourishment
- Genetic programming necessary to support development of embryo for a week
Capacitation
Changes of spermatozoa while in female
- Must occur before spermatozoa can fertilize secondary oocyte
--> Contract with secretions can fertilize secondary oocyte
--> Exposure to conditions in female reproductive tract
Hyaluronidase
- Enzyme breaks down bonds between adjacent follicle cells
- Allows spermatozoa to reach oocyte
Acrosin
- A proteolytic enzyme
- Required to reach oocyte
Acrosomes
- Release hyaluronidase & across
- Penetrate corona radiata, zona pellucida, toward oocyte surface
Oocyte Activation
- Contact and fusion of cell membranes of sperm and oocyte
- Follows fertilization
- Oocyte completes meiosis II, becomes mature ovum
Polyspermy
- Feriliztion by more than one sperm
- Prevented by cortical reaction
Cortical Reaction
