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Epigenetics and Hereditary DNA - Coggle Diagram
Epigenetics and Hereditary DNA
DNA
DNA replication: making copies of DNA. helicase unzips the two strands. polymerase adds new nucleotides to make new DNA.
Protein Synthesis: (transctiption) section in DNA unzips, mRNA reads the bases and creates the corresponding in a line.
Epigenetics
the job of epigenetics is to switch genes on and off
DNA is wrapped around histones. the way DNA wraps around the histone can change the protein produced
tightly wrapping decreases gene expression. loose wrapping increases gene expression
acetylation (adding acetyl group) that enhances gene expression. methylation (adding methyl group) inhibits gene expression
Mitosis and Meiosis
similarities:
both types of cell division, both start off as diploid cells, DNA replication occurs during interphase,
differences:
meiosis produces 4 daughter cells. mitosis 2 daughter cells. mitosis has 1 division, meiosis has 2 divisions. mitosis produces 2 identical cells. meiosis produces non-identical daughter cells. meiosis has crossing over but mitosis doesn't. Daughter cells are diploid, Daughter cells are haploid. meiosis makes sex cells, mitosis for growth and repair
variation:
crossing over, non-disjunction (not separating down syndrome), random assortment
Cancer
malignant: tumour cells spread to other parts of the body. Benign: tumour cells haven't spread
cancer is causes by carcinogens which may increase chance of cancer eg (chemicals, smoking, UV light, x-rays)
STEM Cells
unspecialised cells that can differentiate into other cell types
totipotent: ability to form embyro & membranes that surround it
pluripotent: capable of giving rise to most but not all tissue types
multipotent: give rise to cells that have a particular, only specific cells