DNA, RNA, Genetics, and Reproduction PDF

**Reviewer on DNA, RNA, Genetics, and Reproduction** **DNA (Deoxyribonucleic Acid)** - The molecule that carries genetic instructions for the development, functioning, growth, and reproduction of all known living organisms and many viruses. - **Parts of DNA:** - **Sugar (Deoxyr...

**Reviewer on DNA, RNA, Genetics, and Reproduction** **DNA (Deoxyribonucleic Acid)** - The molecule that carries genetic instructions for the development, functioning, growth, and reproduction of all known living organisms and many viruses. - **Parts of DNA:** - **Sugar (Deoxyribose):** Part of the DNA backbone. - **Phosphate group:** Links the sugar molecules together in the backbone. - **Nitrogenous Bases:** - Adenine (A) - Thymine (T) - Cytosine (C) - Guanine (G) - **Double Helix Structure:** Two strands running in opposite directions, held together by base-pairing rules (A-T and C-G). **RNA (Ribonucleic Acid)** - Plays a crucial role in the synthesis of proteins from the genetic code in DNA. - **Types of RNA:** - **mRNA (Messenger RNA):** Carries genetic instructions from DNA to ribosomes. - **tRNA (Transfer RNA):** Brings amino acids to the ribosomes during protein synthesis. - **rRNA (Ribosomal RNA):** Combines with proteins to form ribosomes. - **Parts of RNA:** - Similar to DNA but with differences: - Sugar is **ribose** instead of deoxyribose. - Nitrogenous bases include **Uracil (U)** instead of Thymine (T). **Gregor Mendel** - Known as the \"Father of Genetics.\" - Conducted experiments with pea plants to study inheritance. - Developed foundational principles of heredity: - **Law of Segregation:** Each organism inherits two alleles for each trait, which separate during gamete formation. - **Law of Independent Assortment:** Genes for different traits segregate independently. **Key Genetic Concepts** - **Heterozygous:** An individual with two different alleles for a specific gene (e.g., Aa). - **Homozygous:** An individual with two identical alleles for a specific gene (e.g., AA or aa). - **Dominant Allele:** The allele that is expressed in a heterozygous pairing (e.g., A in Aa). - **Recessive Allele:** The allele that is masked in a heterozygous pairing (e.g., a in Aa). - **Punnett Square:** A grid used to predict the genotype and phenotype of offspring from parental genetic crosses. **Reproduction** - **Sexual Reproduction:** - Involves two parents contributing genetic material. - Results in offspring with genetic variation. - Example: Humans, animals, and flowering plants. - **Asexual Reproduction:** - Involves a single parent producing genetically identical offspring (clones). - Examples: Binary fission in bacteria, budding in hydra. **Heredity and Genes** - **Heredity:** The passing of traits from parents to offspring. - **Genes:** Units of heredity made of DNA, located on chromosomes, and responsible for determining traits.