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Aug 15, 2020 · During cell division, it is essential that DNA remains intact and evenly distributed among cells. Chromosomes are a key part of the process that ensures DNA is accurately copied and distributed in the vast majority of cell divisions. Still, mistakes do occur on rare occasions. Changes in the number or structure of chromosomes in new cells may ...
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A chromosome is a string of DNA wrapped around associated proteins that give the connected nucleic acid bases a structure. During interphase of the cell cycle, the chromosome exists in a loose structure, so proteins can be translated from the DNA and the DNA can be replicated. During mitosis and meiosis, the chromosome becomes condensed, to be orga...
The chromosome holds not only the genetic code, but many of the proteins responsible for helping express it. Its complex form and structure dictate how often genes can be translated into proteins, and which genes are translated. This process is known as gene expressionand is responsible for creating organisms. Depending on how densely packed the ch...
As seen in the graphic above, chromosomes have a very complex structure. DNA, or deoxyribonucleic acidmakes the base of the structure, as seen on the far left. DNA is made of a two strings of nucleic acid base pairs. The base pairs in DNA are cytosine, adenine, thymine, and guanine. The spiral structure formed by the two strings of DNA is due to co...
Prokaryote Replication
When a single bacteria cell has reached a large enough size, it can reproduce asexually. Although there are no membranes that separate individual organelles in bacteria, the cell will duplicate its DNA and and special chemicals it needs to survive. The DNA exists in a single chromosome, sometimes called a genophore, which is replicated by the individual strands being separated and polymerase building new, corresponding strands. The two chromosomes are separated into individual cells, and the...
Eukaryote Replication
A much more complicated view of chromosomes is present in eukaryotes. In eukaryotes, the DNA is replicated at the end of interphase, the part of the cell cycle in which the cell grows and functions. Much like in the prokaryotes, the DNA strands are separated and new strands are created by enzymes. However, in eukaryotes, there are multiple chromosomes. The new chromosomes remain connected at the centromere, a structure that allows microtubules to connect and holds chromosomes together. These...
Chromatin– DNA and its associated proteins, of which chromosomes are a part.Sister Chromatid– The still connected copies of a chromosome, which will be separated into individual chromosomes during anaphase of mitosis or anaphase II of meiosis.Homologous Chromosomes– Pairs of chromosomes from separate parents that contain the same genetic information, which are separated in anaphase I of meiosis.Sister Chromosome– One of the two new chromosomes created during DNA replication, which are now separated from each other and will soon be in different cells.1. A species has 6 homologous chromosome pairs in somatic, non-gamete cells. How many chromosomes are present in the gamete cells? How many homologous pairs? A. 6 chromosomes, 6 homologous pairs B. 12 chromosomes, 3 homologous pairs C.6 chromosomes, no homologous pairs 2. The DNA has been replicated in a cell containing 4 chromosomes. The cell is g...
Jan 19, 2021 · What is a chromosome? In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure. Chromosomes are not visible in the cell’s nucleus—not even under a microscope—when the cell ...
2 days ago · The human X chromosome is about three times larger than the human Y chromosome, containing about 900 genes, while the Y chromosome has about 55 genes. The unique structure of chromosomes keeps DNA tightly wound around spool-like proteins, called histones. Without such packaging, DNA molecules would be too long to fit inside cells!
Oct 30, 2024 · chromosome, the microscopic threadlike part of the cell that carries hereditary information in the form of genes. A defining feature of any chromosome is its compactness. For instance, the 46 chromosomes found in human cells have a combined length of 200 nm (1 nm = 10 − 9 metre); if the chromosomes were to be unraveled, the genetic material ...
- The Editors of Encyclopaedia Britannica
Chromosomes are the genetic material present in all cells. They are present in the nucleus of a eukaryotic cell. They are a thread-like structure. Each chromosome of a eukaryotic cell contains DNA and associated proteins, known as histone proteins. They are responsible for the hereditary traits and passed from parents to offspring from one ...
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Apr 3, 2023 · A chromosome is a DNA molecule that contains the genetic information for an organism. The chromosomal structure is composed of the organism's DNA and special proteins to form the dense, coiled architecture. The chromosome's tertiary structure is a crucial component in transcription regulation and cellular replication, and division.
