Reproduction and Stem Cells Vocabulary

Vocabulary flashcards about reproduction in animals, covering sexual and asexual reproduction, meiosis, gametes, fertilization, stem cells, and related topics.

Reproduction

The process by which living things produce offspring and pass on their genes to future generations to continue their species.

Asexual Reproduction

The formation of offspring from a single parent cell(s) that are genetically identical to the parent.

Sexual Reproduction

Requires two different sex cells (haploid cells) from two different individuals fusing together to reproduce the first cell (diploid cell) of a new organism.

Mitosis

Cell division that produces genetically identical offspring in asexual reproduction.

Fission

A method of asexual reproduction employed by prokaryotic cells where the circular DNA is copied and cytokinesis separates the membranes, forming two identical cells.

Budding

A method of asexual reproduction where the growth of cells on a parent organism eventually separates to form an autonomous organism.

Fragmentation

A method of asexual reproduction where a new organism grows from a separated portion of a parental organism, developing to be morphologically identical to the parent.

Parthenogenesis

A method of asexual reproduction where an offspring develops from an unfertilized gamete, usually involving the production of a diploid egg cell by the female parent.

Gametes

Sex cells (sperm and egg cell) that fuse during sexual reproduction.

Zygote

A diploid cell formed by the fusion of two haploid gametes during fertilization.

Meiosis

A type of cell division that produces haploid gametes with genetic variation through crossing over and random orientation.

Crossing Over

The exchange of equivalent sections of DNA (genes) between non-sister chromatids of a homologous pair during meiosis I, creating genetic variation.

Random Orientation/Independent Assortment

The random orientation of maternal and paternal homologues during meiosis I, resulting in different allele combinations.

Fertilization

The fusion of egg and sperm cell (gametes) to form a zygote, producing new allele combinations.

Sperm cells

Male gametes, small and motile cells produced by the testes to fertilize the egg.

Egg/ova cells

Female gametes, larger and immotile cells produced by the ovaries containing food reserves for the developing zygote.

Morula

A solid ball of cells formed by the zygote undergoing several mitotic divisions.

Blastocyst

A structure formed as the morula continues to divide, undergoing differentiation and cavitation (cavity formation).

Differentiation

The process by which unspecialized cells develop into specialized cells that can carry out specific functions.

Gene Expression

The process by which the information encoded in a gene is used to direct the assembly of a protein molecule. Differences in gene expression determine the type of cell that forms.

Morphogens

'Form-giving' molecules released by cells in an early embryo that create a concentration gradient determining the fate of other cells.

Stem cell

Unspecialized cells that can divide without limit and have the capacity to differentiate into specific cell types.

Totipotent Stem Cells

Stem cells that can differentiate into any type of cell, including placental cells, giving rise to a complete organism.

Pluripotent Stem Cells

Stem cells that can differentiate into all body cells but cannot give rise to a whole organism.

Multipotent Stem Cells

Stem cells that can differentiate into a few closely related types of body cell.

Stem Cell Niche

The microenvironment within an organism where a stem cell lives and receives instructions by interacting with other surrounding cells and the extracellular environment.