Chromosomes are special structures that store genetic information in all living things. Each chromosome is made of tightly wrapped DNA strands. This helps keep the genetic material safe and organized during cell division.
1. What is DNA?
Nucleotides: DNA is made up of small parts called nucleotides. Each nucleotide has three parts:
Double Helix: The DNA shape looks like a twisted ladder, known as a double helix. The two strands are held together by bonds between matching base pairs (A pairs with T, and C pairs with G). In a single human cell, DNA can be about 2 meters long and has nearly 3 billion of these base pairs.
2. How Are Chromosomes Made?
Turning DNA into chromosomes happens in several steps:
DNA Packaging: In cells with a nucleus (called eukaryotic cells), DNA wraps around proteins called histones. This mix creates a structure called chromatin. A group of DNA wrapped around histone proteins is called a nucleosome.
Supercoiling: The chromatin strands get coiled up tightly. This supercoiling helps the DNA pack into visible chromosomes. When a cell gets ready to divide, the chromatin can shrink down by about 10,000 times to make distinct chromosomes.
Chromosome Structure: Each chromosome has two identical parts called sister chromatids. These chromatids are connected at a point called the centromere. When a cell splits, these parts separate to make sure each new cell gets a complete set of chromosomes.
3. Key Facts and Why They Matter
In short, chromosomes are created from DNA through a process that includes wrapping around proteins, tightly coiling, and organizing properly. This ensures that genetic information is stored and passed down efficiently.
Chromosomes are special structures that store genetic information in all living things. Each chromosome is made of tightly wrapped DNA strands. This helps keep the genetic material safe and organized during cell division.
1. What is DNA?
Nucleotides: DNA is made up of small parts called nucleotides. Each nucleotide has three parts:
Double Helix: The DNA shape looks like a twisted ladder, known as a double helix. The two strands are held together by bonds between matching base pairs (A pairs with T, and C pairs with G). In a single human cell, DNA can be about 2 meters long and has nearly 3 billion of these base pairs.
2. How Are Chromosomes Made?
Turning DNA into chromosomes happens in several steps:
DNA Packaging: In cells with a nucleus (called eukaryotic cells), DNA wraps around proteins called histones. This mix creates a structure called chromatin. A group of DNA wrapped around histone proteins is called a nucleosome.
Supercoiling: The chromatin strands get coiled up tightly. This supercoiling helps the DNA pack into visible chromosomes. When a cell gets ready to divide, the chromatin can shrink down by about 10,000 times to make distinct chromosomes.
Chromosome Structure: Each chromosome has two identical parts called sister chromatids. These chromatids are connected at a point called the centromere. When a cell splits, these parts separate to make sure each new cell gets a complete set of chromosomes.
3. Key Facts and Why They Matter
In short, chromosomes are created from DNA through a process that includes wrapping around proteins, tightly coiling, and organizing properly. This ensures that genetic information is stored and passed down efficiently.