Select Page

Archives: Dictionary


/ˌastrōbīˈäləjē/ Noun 1. Branch of biology that deals with the study of evolution, distribution, and future of life in the universe. ( 2. The science concerned with life in space. (   Syn: Also known as exobiology, exopaleontology, and bioastronomy Word origin: from the Greek ἄστρον, astron (constellation, star); βίος, bios (life); and -λογία, -logia...

Read More


/ˈôtəˌträf/  /-ˌtrōf/ Noun, pl. autotrophs 1. Organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) from simple substances present in its surroundings, generally using energy from light (photosynthesis) or inorganic chemical reactions (chemosynthesis). They are the producers in a food chain, such as plants on land or algae in water. They are able to make their own food, and do not need a living energy or organic carbon source. ( 2. A organism capable of making nutritive organic molecules from inorganic sources via photosynthesis (involving light energy) or chemosynthesis (involving chemical energy). ( 3. Organisms that obtain their carbon and energy (especially the former) without eating other organisms. Some autotrophs (though not all) obtain their energy from photons (i.e., light). (   Syn. producer, “self-feeding” Word origin: Greek autos “self” and trophe...

Read More

Bachmann’s bundle

In the heart’s conduction system, Bachmann’s bundle, or the interatrial tract, is a branch of the anterior internodal tract that resides on the inner wall of the left atrium. It is a broad band of cardiac muscle that passes from the right atrium, between the superior vena cava and the ascending aorta. Bachmann’s bundle is, during normal sinus rhythm, the preferential path for electrical activation of the left atrium. It is therefore considered to be part of the “atrial conduction system” of the heart. ( Named after Jean George...

Read More

Struggling in Biology?

Are You Premed?

Confused about the MCAT? Not sure how to prepare? This guide will show you how