Cell Specification and Differentiation (Chapter 2)

Practice flashcards for Chapter 2: Cell Specification and Differentiation

__ is a process in which cells cease to divide and develop a specialized structural element, giving them a distinct function within the organism.

Differentiation

A __ is a differentiated cell that produces keratin, found in hair and fingernails.

keratinocyte

__ produce melanin, which is the pigmentation in your skin.

Melanocytes

The commitment of a cell is the process of specification and _____

determination.

__ is when the fate of a cell or tissue is capable of differentiating autonomously in a neutral environment, but its fate is not yet sealed and can adjust to different neighbor cells.

Specification

__ is when cells are capable of differentiating autonomously, and their fate is sealed, meaning they will not adjust to new neighbors.

Determination

In , the fate of cells is predetermined based on their position within the egg cytoplasm.

autonomous specification

Within the egg, , such as transcription factors, RNA, and microRNAs, provide positional information for early cell components.

morphological determinants

The yellow cytoplasm in sea squirts contains , which encodes a muscle-specific transcription factor, promoting muscle tissue development.

MACHO mRNA

By removing certain components at different cell stages, scientists can create , which predict what areas of an embryo will develop from a blastocyte based on their location.

fate maps

occurs when cells meet their respective fates by interacting with other cells, sensing their environment and adjusting their strategy.

Conditional specification

__ proposed that each cell of the embryo would develop autonomously and that chromosomes broke into chunks unique to each cell type, which was later found to be incorrect.

Weismann's Germplasm Theory

In , one cell of a two-cell stage embryo was destroyed, resulting in only half the embryo developing, which initially seemed to support autonomous specification.

Rue's experiment

Hans Driesch demonstrated conditional specification by shaking apart four-cell stage embryos, causing each isolated cell to develop , rather than one-fourth of an organism.

fully into the organism

Driesch's __ showed that reshuffling early embryonic cells still resulted in normal development, disproving Weismann's theory of fixed chromosomal chunks and supporting cell pluripotency.

pressure plate experiments

occurs in insects, where a cytoplasm contains many nuclei (syncytium) before cellular walls form, and gradients of factors determine cell fate.

Syncytial specification

__ is a morphological factor in insect eggs that establishes the anterior-posterior gradient, with the highest concentration at the anterior end.

Bicoid

Another gradient-forming factor, __, proceeds in the opposite direction to bicoid, starting highest at the posterior end.

Caudal

predominates in most invertebrates, such as the sea squirt.

Autonomous specification

Most vertebrates and a few invertebrates primarily use for cell fate determination.

conditional specification

predominates in most insect classes, like the fruit fly Drosophila melanogaster.

Syncytial specification