Discovery of vast sex differences in cellular activity has major implications for disease treatment
"We discovered a pronounced 'men are from Mars, women are from Venus' pattern," says marine and environmental biologist Suzanne Edmands.
"We discovered a pronounced 'men are from Mars, women are from Venus' pattern," says marine and environmental biologist Suzanne Edmands.
Cell & Microbiology
Jun 25, 2024
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39
New research led by the University of Bath's Milner Centre for Evolution shows that shorebird species where females breed with multiple males in each season evolve significantly faster than monogamous species. Their findings ...
Plants & Animals
Jun 12, 2024
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111
In an agricultural advancement, scientists have deciphered the genetic underpinnings of watermelon chromosomal translocations, the key to cultivating fruits with fewer seeds.
Plants & Animals
Jul 2, 2024
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Neanderthals, the closest cousins of modern humans, lived in parts of Europe and Asia until their extinction some 30,000 years ago.
Evolution
Jun 17, 2024
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In a study published in the journal Science China Life Sciences, Jianing Yu's group from Shaanxi Normal University and Yuxian Zhu's group from Wuhan University assembled a reference durian genome of 777.8 Mb with 28 chromosomes ...
Evolution
Jul 2, 2024
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A chromosome is an organized structure of DNA and protein that is found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions. The word chromosome comes from the Greek χρῶμα (chroma, color) and σῶμα (soma, body) due to their property of being very strongly stained by particular dyes. Chromosomes vary widely between different organisms. The DNA molecule may be circular or linear, and can be composed of 10,000 to 1,000,000,000 nucleotides in a long chain. Typically eukaryotic cells (cells with nuclei) have large linear chromosomes and prokaryotic cells (cells without defined nuclei) have smaller circular chromosomes, although there are many exceptions to this rule. Furthermore, cells may contain more than one type of chromosome; for example, mitochondria in most eukaryotes and chloroplasts in plants have their own small chromosomes.
In eukaryotes, nuclear chromosomes are packaged by proteins into a condensed structure called chromatin. This allows the very long DNA molecules to fit into the cell nucleus. The structure of chromosomes and chromatin varies through the cell cycle. Chromosomes are the essential unit for cellular division and must be replicated, divided, and passed successfully to their daughter cells so as to ensure the genetic diversity and survival of their progeny. Chromosomes may exist as either duplicated or unduplicated—unduplicated chromosomes are single linear strands, whereas duplicated chromosomes (copied during synthesis phase) contain two copies joined by a centromere. Compaction of the duplicated chromosomes during mitosis and meiosis results in the classic four-arm structure (pictured to the right). Chromosomal recombination plays a vital role in genetic diversity. If these structures are manipulated incorrectly, through processes known as chromosomal instability and translocation, the cell may undergo mitotic catastrophe and die, or it may aberrantly evade apoptosis leading to the progression of cancer.
However, in practice "chromosome" is a rather loosely defined term. In prokaryotes, a small circular DNA molecule may be called either a plasmid or a small chromosome. These small circular genomes are also found in mitochondria and chloroplasts, reflecting their bacterial origins. The simplest chromosomes are found in viruses: these DNA or RNA molecules are short linear or circular chromosomes that often lack any structural proteins.
This text uses material from Wikipedia, licensed under CC BY-SA