bio

Asexual Reproduction

A form of reproduction that involves a single organism creating a genetically identical offspring without the involvement of gametes.

Sexual Reproduction

A form of reproduction that involves the fusion of male and female gametes, leading to offspring with genetic contributions from both parents.

Genetic Diversity

The variation in genetic traits within a population, often increased through sexual reproduction by mechanisms like independent assortment and crossing over.

Acrosomal Reaction

The process where enzymes from the sperm's acrosome are released to help the sperm penetrate the egg's protective layers.

Zygote Formation

The process of forming a fertilized egg after the fusion of sperm and egg nuclei.

Cleavage Divisions

Rapid mitotic divisions of the zygote that produce smaller cells without growth, resulting in a blastula.

Gastrulation

The reorganization of the blastula into a multi-layered structure, establishing germ layers.

Diploblasts

Organisms that have two germ layers: ectoderm and endoderm, such as cnidarians.

Triploblasts

Organisms that have three germ layers: ectoderm, mesoderm, and endoderm, such as vertebrates.

Organogenesis

The process by which specific organs and structures develop from the germ layers.

Induction

The process by which cells interact to influence each other's development.

Cell Migration

The movement of cells to their destined location during developmental processes.

Determination

The stage in development where a cell's fate becomes fixed, committing it to become a specific type of cell.

Extraembryonic Membranes

Membranes outside the embryo that provide support and protection, such as the amnion and chorion.

Amnion

A membrane that surrounds the embryo, providing a cushion of fluid.

Chorion

A membrane involved in gas exchange and contributes to the formation of the placenta in mammals.

DNA Nucleotide

The building blocks of DNA, consisting of a phosphate group, deoxyribose sugar, and a nitrogenous base.

Phosphodiester Backbone

The sugar-phosphate chain formed by covalent bonds between nucleotides, which makes up the structure of DNA.

Complementary Base Pairing

The specific pairing of nitrogenous bases in DNA, where adenine pairs with thymine, and guanine pairs with cytosine.

Helicase

An enzyme that unwinds the DNA double helix at the replication fork.

Okazaki Fragments

Short segments of DNA synthesized on the lagging strand during DNA replication, formed in the opposite direction of the replication fork.