1st Law: Principle of dominance; this means that some alleles(a form of a gene) are dominant and some are recessive. Dominant means that they will appear as a phenotype(physical trait) if they are present in the genotype(genetic code). Recessive means that the phenotype the recessive gene represents will not appear unless there are two recessive alleles. But if they are present along with the dominant allele the trait can be passed on.
2nd Law: Law of segregation; During meiosis, the formation of gametes(sex cells, sperm/eggs), the alleles for the gene that the parent carries will separate. The parent will only pass on one allele for each trait/genotype.
3rd Law: Law of Independent assortment, this means that when the alleles are separating during meiosis they separate independently from other genes. This means that not all dominant genes go to one gamete and all the recessive go to another, but each gene will separate in its own way.
Mutations
DNA
DNA stands for Deoxyribonucleic acid, and is made of hydrogen bonds(Adenine, thymine, Cytosine, and Guanine) twisted into a double helix. DNA a record of instructions telling the cell what it's job is going to be and how it will be assembled/ how it will assemble things.
Chromosomes
Chromosomes are what carry the DNA. In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure. humans have 46 chromosomes or 23 chromosomal pairs.
Refer to our page on Marfan Syndrome for more information