Problem 15 - Biology Today and Tomorrow Without Physiology

Question

__________ consist(s) of nucleotides. a. sugars b. DNA c. RNA d. \(b\) and \(c\)

Step-by-Step Solution

Answer

d. b and c

Step 1: Understand the Components

Identify what nucleotides are. Nucleotides are the building blocks of nucleic acids, which include DNA and RNA.

Step 2: Analyze the Options

Look at each given option: a. sugars - Sugars are carbohydrates, not made of nucleotides. b. DNA - DNA (Deoxyribonucleic acid) is made up of nucleotides. c. RNA - RNA (Ribonucleic acid) is also made up of nucleotides. d. both b and c - This option suggests both DNA and RNA consist of nucleotides.

Step 3: Select the Correct Answer

Based on the analysis, options b and c both consist of nucleotides. Therefore, the correct choice is option d: b and c.

Key Concepts

DNA

DNA, or Deoxyribonucleic Acid, is the hereditary material in almost every living organism. It is like a blueprint for each organism's development and functioning. DNA is composed of long chains of nucleotides. Each nucleotide in DNA comprises three parts: a phosphate group, a sugar called deoxyribose, and one of four nitrogenous bases, which are adenine (A), thymine (T), cytosine (C), and guanine (G).
The sequence of these bases determines the genetic information available for building and maintaining an organism, much like letters in a word or sentence.

Within the DNA double helix structure, the bases pair specifically: adenine pairs with thymine, and cytosine pairs with guanine. This pairing is due to hydrogen bonding between the bases, creating a stable structure essential for DNA replication and function. DNA replication occurs during cell division, ensuring each new cell has the same genetic material.

• DNA is integral to the functioning of living organisms.
• Its structure allows it to store and transmit genetic information.

Understanding DNA's role helps in areas like genetics, forensics, and biotechnology.

RNA

RNA, which stands for Ribonucleic Acid, is crucial for various biological processes in cells. Like DNA, RNA is composed of nucleotides, but there are key differences in structure and function. RNA nucleotides include a sugar called ribose, which has one more oxygen atom than deoxyribose found in DNA. The nitrogenous bases in RNA are adenine (A), uracil (U), cytosine (C), and guanine (G). Note that uracil replaces thymine found in DNA.

RNA's primary role is to act as a messenger between DNA and the proteins synthesized within cells. This process involves several types of RNA:

• Messenger RNA (mRNA) - carries genetic information from DNA to the ribosomes, where protein synthesis occurs.
• Transfer RNA (tRNA) - brings amino acids to ribosomes during protein synthesis.
• Ribosomal RNA (rRNA) - a structural component of ribosomes.

Each type of RNA plays a distinct but interrelated role in gene expression and regulation, ultimately guiding protein production essential for life.

Nucleic Acids

Nucleic acids are vital biomolecules found in every living cell, known primarily for storing and transmitting genetic information. They encompass DNA and RNA, which are both polymers of nucleotides. Each nucleotide is composed of three components: a sugar, a phosphate group, and a nitrogenous base. These constituents form the backbone of nucleic acids and are linked together to create long chains.
Nucleic acids' primary function is to preserve and convey an organism's genetic blueprint so that it can be utilized and expressed appropriately.

Additionally, nucleic acids play a critical role in coding for proteins, the workhorses of cells that perform most functions necessary for life. They are involved in processes such as cellular replication, repair, and gene expression.

• DNA harbors the instructions required for the development, functioning, and reproduction of cells.
• RNA translates and executes these instructions to synthesize proteins and carry out various biological roles.

The interplay between DNA and RNA is fundamental to life, showcasing the importance of nucleic acids in all domains of biology.