Bio 119: Developmental and Reproductive Biology - Lecture 1: Overview of Development and Cell Specification

Vocabulary flashcards covering the introductory concepts of developmental biology, historical landmarks, the animal life cycle, germ layers, and flowering plant embryogenesis.

Development

The slow, progressive process of structural and functional change through which a multicellular organism builds itself over time.

Embryology

The scientific study of animal development from fertilization through the embryonic stages.

Zygote

A single diploid cell produced by the fusion of an egg and a sperm cell during fertilization, which divides to produce all cells of the body.

Indeterminate Growth

A growth pattern in which an organism, such as a plant, continues to grow, elongate, and produce new organs indefinitely throughout its lifespan rather than stopping at a predetermined size.

Regeneration

The developmental capacity of plants and animals to regrow or restore missing or severed body parts.

Metamorphosis

The process of changing body form between developmental stages to achieve sexual maturity.

Oviparity

A reproductive pattern where animals are born from eggs that hatch outside the parent body, seen in birds, frogs, and invertebrates.

Viviparity

A reproductive pattern characterized by giving live birth, typical of mammals.

Ovoviviparity

A reproductive pattern where an organism produces eggs that hatch inside the female body, observed in certain reptiles and sharks.

Holoblastic Cleavage

A cleavage division pattern where the entire egg is cleaved completely into smaller cells, typical of frogs and mammals.

Meroblastic Cleavage

A cleavage pattern where only part of the egg is destined to become the embryo, while the remaining yolk serves as a nutritional source.

Aristotle

The first known embryologist, who conducted the first study of comparative developmental anatomy described in his 350 BCE work "On the Generation of Animals."

William Harvey

Scientist who published "Generation of Living Creatures" in 1651, concluded "Ex ovo omnia" (all from egg), discovered the chick blastoderm, and described amniotic fluid as a shock absorber.

Marcello Malpighi

Italian anatomist who published the first microscopic account of chick development in 1672, detailing the neural tube groove, somites, and vascular circulation.

Embryogenesis

The sequence of developmental stages occurring between fertilization and birth or hatching.

Fertilization

The fusion of mature male and female haploid gametes (pronuclei) to restore the diploid chromosome number and initiate embryonic development.

Genome

The complete collection of genes inherited from parental gametes that instructs the embryo to develop similarly to its parents.

Cleavage

A series of rapid mitotic divisions immediately following fertilization that partitions the single-celled zygote into many smaller cells.

Blastomeres

The individual daughter cells generated by mitotic divisions during the cleavage stage.

Blastula

The spherical embryonic structure formed by blastomeres at the completion of cleavage.

Gastrulation

The developmental stage in which cells of the blastula undergo position rearrangement to generate the three primary germ layers.

Ectoderm

The outermost primary germ layer that gives rise to the epidermis, brain, and nervous system.

Endoderm

The innermost primary germ layer that gives rise to the lining of the digestive gut and the respiratory system.

Mesoderm

The intermediate primary germ layer that gives rise to connective tissue, muscle, blood, the heart, skeleton, and kidneys.

Organogenesis

The process by which germ layer cells interact through chemical signaling and rearrange to generate distinct tissues and organs.

Germ Cells

The group of specialized cells and their precursors set aside specifically for reproduction to produce the next generation of gametes.

Somatic Cells

All non-germ cells that form the normal tissues and structures of an individual's body.

Blastopore

An invagination formed during gastrulation that marks the future dorsal side of the embryo and provides a pathway for migrating mesodermal and endodermal cells.

Notochord

A rod of condensed mesodermal cells along the dorsal midline that emits chemical signals instructing the overlying ectoderm to develop into nervous tissue.

Neurula

The embryonic stage characterized by neural precursor cells elongating and folding along the dorsal midline to create the neural tube.

Somites

Segmented blocks of mesoderm adjacent to the neural tube and notochord that form back muscles, spinal vertebrae, and the dermis.

Diploid Sporophytic Stage

The spore-bearing, $2n$ phase of the plant life cycle that produces spores via meiotic division.

Haploid Gametophytic Stage

The gamete-producing, $n$ phase of the plant life cycle that produces sperm and egg cells.

Endosperm

A specialized nutrient-storing tissue layer within flowering plant seeds that nourishes the developing embryo.

Cotyledons

Embryonic leaves formed during plant embryogenesis that provide nutrients to the developing plant.

Shoot Apical Meristem (SAM)

A region of plant stem cells located at the shoot tip that builds above-ground structures such as stems, leaves, and flowers.

Root Apical Meristem (RAM)

A region of plant stem cells located at the root tip responsible for driving underground vertical root growth.

Dermal Tissue

The plant tissue layer formed during embryogenesis that produces the outer epidermis of the plant body.

Ground Tissue

Internal plant tissue that forms the cortex, functioning in nutrient storage, support, and photosynthesis.

Vascular Tissue

Plant conducting tissue consisting of xylem for water transport and phloem for the transport of sugars and photosynthetic nutrients.

Meristems

Perpetual stem cell niches situated at the apical and basal tips of plants that allow continuous self-renewal and indeterminate growth throughout adulthood.