Membranes

• Prophase (mitosis)


  chromosomes condense, nuclear envelope breaks down, centrioles move to poles of cell, spindle fibres begin to form
• Metaphase (mitosis)


  Spindle fibres attach to centromeres, chromosomes arranged at metaphase plate on cell equator
• Anaphase (mitosis)

  Centromeres divide, spindle fibres contract and pull chromosomes to opposite ends, sister chromatids separated
• Telophase (mitosis)


  chromosomes decondense, new nuclear envelopes formed, new nucleoli formed
• Prophase I (Meiosis)

  chromosomes condense, nuclear envelope breaks down, centrioles move to poles of cell, spindle fibres begin to form
• Metaphase I (Meiosis)


  mitosis, but bivalents line up at metaphase plate instead of individual chromosomes
• Anaphase 1 (Meiosis)

  mitosis, but homologous chromosomes pulled to opposite poles
• Telophase 1 (Meiosis)


  chromosomes decondense, new nuclear envelopes formed, new nucleoli formed
• Prophase 2 (Meiosis)


  chromosomes condense, nuclear envelope breaks down, centrioles move to alternate poles, spindle fibres begin to form
• G1 phase


  Cellular contents, excluding the chromosomes, are duplicated
• S phase


  Each chromosome is duplicated
• G2 phase


  Duplicated chromosomes checked for errors, repaired if necessary
• totipotent stem cell


  stem cell that can differentiate into any type of cell
• pluripotent stem cell


  stem cell that can form all tissue types but not whole organisms
• multipotent stem cell


  stem cell that can form a range of cells within a certain type of tissue
• cell


  smallest unit of life
• tissue


  group of cells with a common function
• organ


  group of tissues with shared function/functions
• organ system

  group of organs with related functions
• differentiation


  process by which a cell becomes specialised
• stem cell


  undifferentiated cell
• Adaptations of erythrocytes


  biconcave shape, no nucleus, flexible, contain haemoglobin
• adaptations of neutrophils


  granular cytoplasm contains lysosomes, flexible shape
• adaptations of sperm cells

  acrosome contains digestive enzymes, flagellum, lots of mitochrondria
• adaptations of palisade cells

  rectangular box shape, thin cell wall, large vacuole, lots of chloroplasts, chloroplasts can move
• adaptations of root hair cells

  large SA, thin permeable cell wall, mitochondria, solutes in cytoplasm
• adaptations of guard cells

  cell walls thicker on inside, changes shape asymmetrically to close and open stoma
• adaptations of squamous epithelium

  only one cell thick
• adaptations of ciliated epithelium


  cilia on surface, goblet cells release mucus
• adaptations of cartilage


  firm and flexible, composed of chondrocyte cells embedded in extracellular matrix
• adaptations of muscle


  muscle fibres contain myofibrils, myofibrils contain contractile proteins
• xylem tissue


  vascular tissue responsible for water and mineral transport, composed of vessel elements, walls strengthened with lignin, pits present
• phloem tissue


  vascular tissue responsible for transport of dissolved solutes, composed of columns of sieve tube cells separated by perforated sieve plates, companion cells present
• bivalent


  a pair of homologous chromosomes
• allele


  different versions of the same gene
• somatic cell


  any cell other than a gamete
• chromatid

  single strand of replicated chromosome
• mitosis


  nuclear division giving rise to genetically identical daughter cells
• locus


  specific position on a chromosome where a particular gene is located
• meiosis

  cellular division that happens in the reproductive organs to produce gametes