- Schleiden and Schwann cell theory
- Spontaneous generation (creation of living organisms from nonliving components)
- Fixity of species (animals and plants have remained unchanged since beginning of time)
- Natural Selection
- Mendel’s genetics
Chromosome theory of inheritance
- Inherited traits are controlled by genes residing on chromosomes that are transmitted
through gametes, maintaining genetic continuity.
- Humans have a diploid number of chromosomes (46)
- Exist in pairs – homologous chromosomes
- Mitosis transfers a diploid amount of chromosomes into daughter cells. (makes body
- Meiosis transfers a haploid amount of chromosomes into gamete cells. (sex cells)
- Caused by mutations (any heritable trait that causes genetic variation)
- Alleles are alternative forms of a gene and produce observable changes in the
- Genotype is a set of alleles for a given trait that are carried by an individual.
Search for Chemical Nature of DNA.
- Genes are carried on chromosomes - Bacteriophages (bacteria that attack viruses) were used to show that DNA was
responsible for genetic material and not the protein because its protein cap stayed on
the outside of an infected cell and the DNA entered it.
- DNA is made up of nucleotides, each containing one of the 4 bases – ATGC. These
bases specific the amino acid sequence that codes for the protein
- Transcription – DNA to mRNA
- Translation – mRNA to protein (amino acid sequence)
- Info encoded in mRNA is called the genetic code.
- Proteins are very common in the body – enzymes, hemoglobin, histones, etc.
- Sickle cell anemia is caused by mutant form of the protein hemoglobin.
- Discovered that bacteria produce enzymes that cut viral DNA at specific sites to get rid
of it from its DNA. We can also use this to insert or remove a fragment of a DNA into a
Biotechnology in Genetics and Medicine
- DNA microarray can study the whole genome to determine any mutations in it
- Gene therapy - clinicians transfer normal genes into individuals affected with genetic
- Genomics – study of genes
- Proteomics - identifies the set of proteins present in a cell under a given set of conditions
and additionally studies the post-translational modification of these proteins, their
location within cells, and the protein–protein interactions occurring in the cell.