Development and Inheritance Flashcards

Flashcards to review key concepts from the Development and Inheritance lecture.

What is development?

Gradual modification of anatomical structures and physiological characteristics from fertilization to maturity.

What occurs during Prenatal development?

Embryonic and fetal developmental stages.

What occurs during Postnatal development?

From birth to maturity

What is inheritance (heredity)?

Transfer of genetically determined characteristics from generation to generation

What is Genetics?

Study of the mechanisms responsible for inheritance

What is fertilization?

Fusion of two haploid gametes, each containing 23 chromosomes.

What does fertilization produce?

A zygote containing 46 chromosomes.

Where does fertilization occur?

Occurs in the uterine tube within a day after ovulation

What is capacitation?

Functional maturation of the sperm that must occur before it can fertilize the secondary oocyte.

What occurs during the Acrosomal Reaction?

Sperm acrosome releases enzymes to penetrate corona radiata and reach the oocyte

What is the function of zonal inhibiting proteins (ZIPs)?

Inactivate sperm receptors and harden the zona pellucida which acts as a block to polyspermyfertilization by more than one sperm

What is Female pronucleus?

Reorganized nuclear material remaining in the ovum after the completion of meiosis II

When does the first cleavage division nears completion?

The first cleavage division nears completion about 30 hours after fertilization

What is Gestation?

Time spent in prenatal development

What is Cleavage?

Sequence of cell divisions that begins immediately after fertilization

What is Implantation?

Blastocyst attaches to endometrium and invades maternal tissues

What is Placentation?

The placenta develops to permit exchange between maternal and embryonic blood

What is Embryogenesis?

Formation of a viable embryo which establishes the foundations for all major organ systems

What is Gastrulation?

Cell migration in the early embryo that forms an embryonic disc

What is developed from the Ectoderm?

Integumentary system: epidermis, nails, hair follicles, hairs, glands communicating with the skin (sweat, mammary and sebaceous glands)

What part of the Integumentary system is developed from the Mesoderm?

Dermis and hypodermis

What part of the Endocrine system is developed from the Endoderm?

Thymus, thyroid gland and pancreas

Which cells secrete human chorionic gonadotropin (h C G)?

Trophoblast cells and the chorion secrete human chorionic gonadotropin (h C G)

What is Induction?

Cells release chemical substances that affect differentiation of other embryonic cells

What does the early embryo contain?

Mesonephric ducts (Wolffian ducts) and Paramesonephric ducts (Mullerian ducts)

If TDF is present, what happens?

Wolffian ducts develop into testes and produce testosterone

If TDF is absent, what happens?

Mullerian ducts develop into female reproductive structures

What are the function of human chorionic gonadotropin (h C G)?

Appears in maternal bloodstream soon after implantation and allows the corpus luteum to persist for 3 – 4 months

What are Dizygotic twins (“fraternal twins”)?

Two separate oocytes are ovulated and fertilized

What are Monozygotic twins (“identical twins”)?

Separation of the blastomeres early during cleavage and Splitting of the inner cell mass before gastrulation

What are Chromosomes?

Made of supercoiled chromatin (D N A and proteins)

What are Genes?

Functional segments of D N A and each gene carries the information to direct synthesis of a specific polypeptide

What is Genotype?

Genetic makeup of an organism and chromosomes and their genes

What is Phenotype?

Physical characteristics and Phenotypic trait – specific character variant, such as blue eye

What is Karyotype?

Set of chromosomes in an individual

What is the Locus?

The position of a gene on a chromosome

What are Alleles?

Various forms of a given gene

What is Homozygous?

Homologous chromosomes carry the same allele

What is Heterozygous?

Homologous chromosomes carry different alleles

What is Punnett square?

Simple box diagram used to predict characteristics of offspring

What are X-linked genes?

Found on the X chromosome but not on the Y

What is Human genome?

Full set of genetic material (D N A) in our chromosomes

What is Gene therapy?

Medical approach that treats genetic disorders by inserting corrective genes into a patient’s cells