Biology Genetics Notes
Introduction: * Genetics are composed of five main areas: DNA replication, meiosis, reproduction, adaptation and evolution. The body is composed of 46 chromosomes (23 from your mother and 23 of your father). The genes are in your cells in the nucleus and some in the mitochondria. The genes are a small part of a long molecule called DNA. DNA is a double stranded molecule (sugar, phosphate and four different bases: Adenine, Thymine, Cytosine and Guanine). The bases in the DNA are in charge of writing the genetic code. Genes are the code to make specifically proteins (for example, that protein that makes your eyes be blue), and these genes are inherited through the different generations. They also tell a cell how to function, there are gene regulators which turn genes on and off. DNA is organized into pieces called chromosomes.
Blending and Gregor Mendel’s way of inheritance:
Blending: Consisted that the offspring will inherit the genes from their parents so it will be half way in between. For example if one parent was small and the other one big, the offspring will turn out to be medium size.
Gregor Mendel: Suggested that there would be a recessive and a Dominant allele. If the offspring inherited the genes from their parents the recessive gene will always be masked by the dominant gene (in the example above, the tallest parent would have a dominant tall allele that would mask the recessive small allele causing the offspring to be tall). *
Gregor Mendel’s Experiments:
Method: Consisted of crossing a variety of tea plants to see after what characteristics would the offspring have.
Result: The pea plants came with characteristics visible in only one of their parents but not both.
Conclusion: The alleles that are formed by the inheritance of genes from their parents had recessive and dominant properties. Recessive alleles would only be seen in an homozygous state while if it had an heterozygous state (in presence with a dominant allele)
Blending and Gregor Mendel’s way of inheritance:
Blending: Consisted that the offspring will inherit the genes from their parents so it will be half way in between. For example if one parent was small and the other one big, the offspring will turn out to be medium size.
Gregor Mendel: Suggested that there would be a recessive and a Dominant allele. If the offspring inherited the genes from their parents the recessive gene will always be masked by the dominant gene (in the example above, the tallest parent would have a dominant tall allele that would mask the recessive small allele causing the offspring to be tall). *
Gregor Mendel’s Experiments:
Method: Consisted of crossing a variety of tea plants to see after what characteristics would the offspring have.
Result: The pea plants came with characteristics visible in only one of their parents but not both.
Conclusion: The alleles that are formed by the inheritance of genes from their parents had recessive and dominant properties. Recessive alleles would only be seen in an homozygous state while if it had an heterozygous state (in presence with a dominant allele)