Whether inked cards are legal largely depends on the context in which they're being used. In the realm of collectible card games like Magic: The Gathering, inked cards, which are modified with ink for cosmetic reasons, are usually permissible in casual play if all players agree. However, for official tournaments, the legality of inked cards is subject to the event's rules. The main concern is whether the modification causes the card to become marked, making it identifiable from the back and potentially giving a player an unfair advantage. Therefore, in competitive settings, inked cards are often subject to scrutiny and may be disallowed if they're deemed to provide such an advantage or if they obscure any official markings of the card. For other card games or in non-game contexts, legibility and the card's integrity after being inked are key factors in determining its acceptability.

RNA (Ribonucleic Acid) is not an amino acid. Instead, it is a nucleic acid, one of the fundamental macromolecules essential for all known forms of life. Amino acids are the building blocks of proteins and play various roles in metabolism and physiology. In contrast, RNA is made up of a long chain of nucleotide units, each composed of a sugar (ribose), a phosphate group, and a nitrogenous base. RNA is crucial in the coding, decoding, regulation, and expression of genes. It plays a pivotal role in protein synthesis where, through the processes of transcription and translation, the genetic code in the DNA is translated into the amino acid sequence of proteins. RNA and amino acids interact closely in cellular functions, but they are distinct entities with different roles and structures.

Fiber is an essential part of a healthy diet, known for aiding digestion and preventing constipation. It's broadly categorized into two types: soluble and insoluble. Soluble fiber dissolves in water and can help lower glucose levels and blood cholesterol. Good sources include oats, peas, beans, apples, citrus fruits, carrots, barley, and psyllium. Insoluble fiber, on the other hand, helps food move through your digestive system and increases stool bulk, found in whole wheat flour, wheat bran, nuts, beans, and vegetables such as cauliflower, green beans, and potatoes. Incorporating a mix of both fiber types by eating a variety of these foods is beneficial for maintaining good health and digestion.