Heredity and Genetic Processes

Heredity and Hereditary Changes

• Heredity is the transfer of biological characteristics from one generation to another via genes.
• Gregor Johann Mendel pioneered modern genetics.
• Hugo de Vries's mutational theory explained sudden changes.
• Walter Sutton observed paired chromosomes (1902).
• Avery, McCarty, and McLeod proved DNA is genetic material (1944) in most organisms
• Francois Jacob and Jack Monod proposed a DNA-based protein synthesis model (1961).
• Recombinant DNA technology emerged from this.
• Heredity is helpful for diagnosing, treating, and preventing genetic disorders, producing hybrid varieties, and industrial processes using microbes.

Transcription, Translation, & Translocation

• DNA structure and different types of RNA are explained.
• Genetic disorders and their names are discussed.
• DNA stores protein synthesis information, which is then used to make proteins via RNA.
• The process of making RNA from DNA is called transcription.
• mRNA is produced complementary to DNA.
• tRNA brings amino acids to ribosomes to assemble proteins (translation).
• rRNA is important to translation in ribosomes.
• This process is called translocation when ribosome moves along mRNA.

Evidences of Evolution

• Evolution is the gradual change in organisms over time.
• Morphological similarities in animals and plants suggest shared ancestry.
• Anatomical similarities in bone structure in different animals suggest a common ancestor.
• Vestigial organs are organs that are reduced in size or function but were once useful in ancestors.
• Fossils are remains of organisms preserved in the earth.
• Studying fossils helps determine the evolution of organisms.
• Gradual change results in new species formation.

Speciation

• Species are groups of organisms capable of interbreeding.
• Speciation is the process of new species formation.
• Geographical isolation leads to reproductive isolation which can lead to speciation.
• Genetic variation is important to new species formation.

Human Evolution

• Humans evolved from simple unicellular organisms.
• Monkey-like ancestors evolved from ancestors similar to modern lemurs.
• Ape-like animals reached Asia, becoming different species.
• Gorillas and chimpanzees evolved from other apes.
• Humans developed erect posture about 2 million years ago.
• Ramapithecus is an early human ancestor.
• Early humans developed agriculture, writing, and complex societies.
• Early hominid ancestors were very similar to apes.

Lamarckism

• Proposed that acquired characteristics could be passed down to offspring.
• Giraffe's long neck was due to generations' extending their necks.
• Evolution occurs via organs changing due to use or disuse.
• This theory has been refuted by modern evolutionary theory.