Biology

• Law of Dominance 


  In a cross of parents that are homozygous for a trait only one form of the trait will appear in the next generation
• Law of segregation 


  During the formation of gamides the 2 alleles responsible for each trait seperate from each other. Alleles for a trait are the recombined at fertilization, producing the genotype for the trait of the offspring
• Law of independence


  Alleles for different traits (colour & texture) are distributed to sex cells and offspring independently to one another
• Alleles


  Alternative forms of a gene

  Located on corresponding position of homologous chromosomes
• Homozygous


  The same allele
• Heterozygous 


  Different alleles
• Gender (X-linked inheritance)


  The trait is located on the X chromosome. While females have 2 alleles ( XaXA), males only have one (XaY)
• Genetic


  Each DNA string has 23 sections (chromosomes). Each cell has 46 chromosomes (22 from your dad, 22 from your mom and 2 sex chromosomes). The complete genetic material is called genome
• DNA


  Molecule that stored the information in a sequence of four bars (A + F;C + G)
• Semi-conservative replication 


  DNA is copied for cells to multiply. Therefore the 2 strands of DNA unwind from each other and each acts as a template for synthesis of a new, complementary strand
• Mitosis

  1. Prophase: the nuclear envelope breaks, the centrosomes separate and a structure called the mitotic spindle (spindle fibre) begins to form
  2. Metaphase: the DNA lines up due to mitotic spindles pulling on the sister chromatids 
  3. Anaphase: the two sister chromatids of each chromosome are moved towards the opposite centrosome by the spindle fibers
  4. Telophase: the nuclear envelope reforms and chromosomes condense. The mitotic spindke breaks
• DNA (Protein)


  The DNA is made up of a phosphate group containing sugar (deoxyribose) and base. In total it's called nucleotide.
• Protein


  A protein consists of about 450 amino acids 52 of them are insuline and 34.350 are titin (ordered diversely). Amino acids can be produced by us or consumed.
• Gene


  Information in the DNA to build proteins
• Meiosis


  1. Prophase I

  2. Metaphase I

  3. Anaphase I

  4. Telophase I

  5. Prophase II

  6. Metaphase II

  7. Anaphase II

  8. Telophase II
• Prophase I

  • Nuclear envelope brakes
  • Centrosomes separate
  • Spindle fibers form
  • Crossing over between chromosomes
• Metaphase I

  • Chromosomes line up due to spindle fibers
• Anaphase I

  • Chromosomes pull apart but sister chromatids are still attached
• Telophase I

  • Nuclear envelope forms around sister chromatids
• Prophase II

  • Nuclear envelope breaks
  • Centrosomes separate
  • Spindle fibers form
• Metaphase II

  • Sister chromatids line up
• Anaphase II

  • Sister chromatids are pulled apart
• Telophase II

  • Nuclear envelope reforms around haploid chromatids
• Transcription


  Process by which a cell makes an RNA copy of a piece of DNA. This RNA copy called messenger RNA carries the genetic information needed to make proteins in the cell. It carries the information from the DNA in the nucleus of the cell to the cytoplasm where proteins are made
• Translation


  Process in living cells in which proteins are produced using RNA molecules as template
• Crossing Over


  Crossing over is a cellular process that happens during meiosis when chromosomes of the same type are lined up. When two chromosomes — one from the mother and one from the father — line up, parts of the chromosome can be switched. The two chromosomes contain the same genes, but may have different forms of the genes.