• DNA is, however, supercoiled and wound around "packaging" proteins called histones (in eukaryotes), and both superstructures are vulnerable to the effects of DNA damage. (wikipedia.org)
  • Diatoms are classified as eukaryotes , organisms with a nuclear envelope -bound cell nucleus , that separates them from the prokaryotes archaea and bacteria . (eol.org)
  • [1] In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA damage, resulting in tens of thousands of individual molecular lesions per cell per day. (wikipedia.org)
  • DNA damage, due to environmental factors and normal metabolic processes inside the cell, occurs at a rate of 10,000 to 1,000,000 molecular lesions per cell per day. (wikipedia.org)
  • Unusually for autotrophic organisms, diatoms possess a urea cycle , a feature that they share with animals , although this cycle is used to different metabolic ends in diatoms. (eol.org)
  • A unique feature of diatom anatomy is that they are surrounded by a cell wall made of silica (hydrated silicon dioxide ), called a frustule . (eol.org)
  • [22] Another classification divides plankton into eight types based on size: in this scheme, diatoms are classed as microalgae. (eol.org)
  • After a GSC divides,the daughter still in contact with cap cells remains a stem cell, whereas the daughter that is more distant from cap cells differentiates into a cystoblast. (biologists.com)
  • Other lesions induce potentially harmful mutations in the cell's genome, which affect the survival of its daughter cells after it undergoes mitosis . (wikipedia.org)
  • Individual cells range in size from 2 to 200 micrometers. (eol.org)
  • the maximum life span of individual cells is about six days. (eol.org)
  • The DNA repair ability of a cell is vital to the integrity of its genome and thus to the normal functionality of that organism. (wikipedia.org)
  • In mammals, constitutive β-catenin causes over-proliferation and abnormal differentiation of skin cells, resulting in skin cancer formation. (biologists.com)