Biology Test 118

Lysine is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group, an α-carboxylic acid group, and a side chain lysyl, classifying it as a basic, charged, aliphatic amino acid. It is encoded by the codons AAA and AAG

Tensor tympani is the larger of the two muscles of the tympanic cavity. Its role is to dampen sounds, such as those produced from chewing.

The small intestine is all about maximising the surface area.

The International Society of Blood Transfusion (ISBT) identifies about 30 major blood group systems, including the ABO and Rh systems.

Trachoma is an infectious disease caused by bacterium Chlamydia trachomatis. The infection causes a roughening of the inner surface of the eyelids. This roughening can lead to pain in the eyes, breakdown of the outer surface or cornea of the eyes, and eventual blindness. Blinding endemic trachoma results from multiple episodes of reinfection that maintains the intense inflammation in the conjunctiva. Without reinfection, the inflammation will gradually subside. The conjunctival inflammation is called "active trachoma" and usually is seen in children.

The Maximum Contaminant Level (MCL) of nitrate as nitrogen (NO₃N) is 10 mg/L (or 10 parts per million) for the safety of drinking water. Nitrate levels at or above this level have been known to cause a potentially fatal blood disorder in infants under six months of age called methemoglobinemia or 'blue baby syndrome'; in which there is a reduction in the oxygen-carrying capacity of blood.

The delay of senescence of leaves and other organs of the plants by cytokinins is called Richmond Lang effect.

Watermelon snow, also called snow algae, pink snow, red snow, or blood snow, is a phenomenon caused by Chlamydomonas nivalis, a species of green algae containing a secondary red carotenoid pigment (astaxanthin) in addition to chlorophyll.

Chlamydomonas nivalis owes its red color to a bright red carotenoid pigment, which protects the chloroplast from intense visible and also ultraviolet radiation, as well as absorbing heat, which provides the alga with liquid water as the snow melts around it.

Oxytocin is a neurohormone. It is a peptide hormone and neuropeptide. Oxytocin is normally produced by the paraventricular nucleus of the hypothalamus and released by the posterior pituitary. It plays a role in social bonding, sexual reproduction, childbirth, and the period after childbirth.

The term proofreading is used in genetics to refer to the error-correcting processes. In bacteria, all three DNA polymerases (I, II and III) have the ability to proofread, using 3' → 5' exonuclease activity. When an incorrect base pair is recognized, DNA polymerase reverses its direction by one base pair of DNA and excises the mismatched base. Following base excision, the polymerase can re-insert the correct base and replication can continue

In eukaryotes only the polymerases that deal with the elongation (delta and epsilon) have proofreading ability (3' → 5' exonuclease activity).