L4 - Pre-Natal Development Flashcards

Flashcards on prenatal development, covering conception, stages of prenatal development (germinal, embryonic, fetal), genetic influences, potential abnormalities, and environmental factors affecting prenatal health.

Conception

Occurs when an egg from the mother is fertilized by a sperm from the father.

Ovum (Egg)

The largest cell in the human body; released from one of the mother's ovaries during ovulation and travels into the fallopian tube.

In Vitro Fertilization (IVF)

The most effective and common form of assisted reproductive technology, involving fertilization outside of the body.

Germinal Stage

The stage of prenatal development from 0-2 weeks, characterized by the zygote and initial cell specialization.

Embryonic Stage

The stage of prenatal development from 3-8 weeks, during which the heart starts to beat and the embryo is most vulnerable to teratogens.

Fetal Stage

The stage of prenatal development from 9 weeks to birth, marked by the formation of hands, feet, and facial features.

Zygote (in Germinal Stage)

Specialization of cells begins, and the placenta starts to form.

Embryo (in Embryonic Stage)

Heart starts to beat; most vulnerable to teratogens.

Fetus (in Fetal Stage)

Feet and hands have formed; facial features are forming.

Chromosomes

Threadlike structures that come in 23 pairs, containing the genetic substance DNA.

DNA (Deoxyribonucleic Acid)

A complex molecule that contains genetic information.

Genes

Units of hereditary information composed of DNA, directing cells to reproduce and manufacture proteins.

Mitosis

Cell division where the cell's nucleus duplicates itself, forming two new cells with the same DNA.

Meiosis

Cell division forming eggs and sperm (gametes), resulting in four cells each with half the genetic material.

Fertilization

The fusion of an egg and a sperm to create a single cell with 23 paired chromosomes.

Dizygotic Twins (Fraternal Twins)

Twins resulting from the mother's body releasing two ova that are both fertilized.

Monozygotic Twins (Identical Twins)

Twins resulting from a single fertilized ovum splitting into two.

Genotype

A person’s genetic heritage; the actual genetic material.

Phenotype

The way an individual’s genotype is expressed in observed and measurable characteristics.

Dominant-Recessive Genes Principle

One gene of a pair always exerts its effects, overriding the potential influence of the recessive gene.

Sex-Linked Genes

When a mutated gene is carried on the X chromosome, affecting males differently than females.

Polygenic Inheritance

Trait is produced from the cumulative effects of many genes.

Epigenetic View

Development is the result of an ongoing, bidirectional interchange between heredity and the environment.

Teratogen

Any disease, drug, or other environmental agent that can harm a developing fetus.