146 results found

Search Results for: exchange

Chorion

Chorion Definition The chorion is a membrane that develops around the developing fertilized egg. It begins to develop... Read More

Respiration

Organization of the Respiratory System Each lung is composed of air sacs called alveoli - the sites of gas exchange with... Read More

System

A system pertains to interdependent or interrelated objects comprising and functioning as a whole. In biology, it may refer... Read More

Ventilation

Ventilation Definition Often when persons think of ventilation, they think of getting clean or enough air into a room. This... Read More

Parenchyma

Parenchyma Definition What does parenchyma mean? Let's define the word "parenchyma". Most of the functional tissues in... Read More

Prophase I

Organisms all use mitosis to create more cells in the body. Meiosis, a similar process, is used in some organisms to undergo... Read More

Book lungs

Book Lungs Definition Lungs are known as the organs that help organisms breathe. When we think of lungs, we think of the... Read More

Mutualistic symbiosis

Mutualistic Symbiosis Definition In order to understand what a mutualistic symbiotic relationship means, we will break down... Read More

Conjugate

Conjugate Definition Conjugate in a broader sense refers to related pairs of substances or entities that are interconnected... Read More

Meiosis

What is Meiosis? A simple definition of meiosis would be is this: meiosis is the process of cell division that results in... Read More

Osmotic pressure

Osmotic Pressure Definition Osmotic pressure is the pressure caused by a difference in the amounts of solutes (or... Read More

Circulation

Blood Blood is composed of a liquid, plasma, and blood cells such as erythrocytes (red blood cells,) leukocytes (white... Read More

Organ

Definition Of Organ An organ is a collection of tissues that carries out a function or set of related ones. An organ often... Read More

Alveolus

Definition noun, plural: alveoli (1) pulmonary alveolus; air sac (2) (general) A concave cavity or pit alveolar,... Read More

Embryo

An embryo refers to the early developmental stage of a multicellular organism that follows fertilization. This stage... Read More

Respiratory system

Definition noun An organ system comprised of organs and structures associated for respiration or gas exchange Supplement An... Read More

Simple squamous epithelium

Simple Squamous Epithelium Definition Simple squamous epithelium, also known as simple squamous epithelial tissue or... Read More

Communicable disease

Definition noun, plural: communicable diseases A type of disease that is contagious since the agent of the disease may be... Read More

Pneumatophore

Definition noun, plural: pneumatophores (botany) A specialized aerial root, such as in certain mangrove species, that stick... Read More

Alveolar cell

Definition noun, plural: alveolar cells The cell lining the pulmonary alveolus; the cell of the air sac of the... Read More

Sexual reproduction

Sexual reproduction is a mode of reproduction involving the fusion of haploid female gamete (egg cell) and haploid male... Read More

Archaea

Archaea is a group of prokaryotic life forms distinct from bacteria forming a separate domain of life. They possess... Read More

Arthropod

Arthropod Definition What is an arthropod? An arthropod is an invertebrate living organism characterized by the presence of... Read More

Telophase

Telophase is the stage of cell division characterized by the decondensation of chromosomes, and the nuclear envelope... Read More

Genetic variability

Genetic Variability Definition Genetic variability refers to the tendency of individual genetic characteristics in a... Read More

Homologous chromosome

A homologous chromosome pertains to one of a pair of chromosomes with the same gene sequence, loci, chromosomal length, and... Read More

Bacteria

Bacteria Definition What are bacteria? What is the definition of bacteria in biology? Bacteria are defined as organisms... Read More

Chromatids

Chromatid Definition Chromatids are found inside our cells. Chromatids are condensed chromosomes distinguishable during... Read More

Roots

Upon seed germination, the embryo root, called the radicle, grows and develops into the first root. The radicle may thicken... Read More

Anaerobic respiration

Anaerobic Respiration Definition What is anaerobic respiration? Anaerobic (cellular) respiration is a respiratory process... Read More

Osteon

What is an Osteon? In osteology (the study of bony structures and skeleton), the osteons (or Haversian systems) are the... Read More

Bivalent

Bivalent Definition What is bivalent? In genetics, bivalent is used in describing homologous chromosomes (referred to as... Read More

Species

Every living organism is unique when you observe its morphological, anatomical, molecular, genetic, biochemical, chemical,... Read More

Independent Assortment and Crossing Over

Reviewed by: Mary Anne Clark, Ph.D. The previous tutorial investigates the process of meiosis, where... Read More

Animal

Animal Definition An animal (plural: animals) refers to any of the eukaryotic multicellular organisms of the biological... Read More

Independent Assortment

Independent Assortment Definition Independent assortment refers to the alleles or genes that sort into the newly formed... Read More

Process

Process Definition What is a process? In biology, a process (plural: processes) means any of the various biological... Read More

Turgor pressure

In biology, turgor pressure pertains to the pressure that is exerted by the fluid (e.g. water) against the cell wall. It is... Read More

Permutation

permutation 1. The act of permuting; exchange of the thing for another; mutual transference; interchange. The violent... Read More

Sympatric speciation

Speciation is a process of evolution through which two different existing populations evolve and a distinct species form. It... Read More