Heredity
Class 10: Science
Heredity, Genetics, Gene, Cell Division, DNA, RNA, Chromosome, Sex Determination in Humans, Mendel’s Experiment, Genotype and Phenotype, Mendel’s Law, Genetic Technology, Selective Breeding, Artificial Insemination, In Vitro Fertilization
Heredity
Heredity is the process by which traits and characteristics are passed from parents to offspring through genes.
- Traits are features or qualities (e.g., eye color, height) inherited from parents.
- Variations are the differences in traits among individuals.
Genetics
Genetics is the branch of biology that studies heredity and variation in organisms. Gregor Mendel is known as the Father of Genetics. He conducted experiments on pea plants to explain inheritance patterns.
Gene
A gene is a segment of DNA that carries the instructions for making a specific protein, which determines a trait.
Example: Genes for eye color or hair type.
Cell Division
Cell Division is the process where a mother cell splits into two or more daughter cells. There are two types of cell division.
1. Mitosis: Produces two identical daughter cells, essential for growth and repair.
- Steps: Prophase, Metaphase, Anaphase, Telophase, Cytokinesis.
2. Meiosis: Produces gametes (sperm and egg) with half the chromosome number, essential for reproduction.
- Steps: Meiosis I and Meiosis II.
DNA (Deoxyribonucleic Acid)
DNA is the hereditary material in humans and most other organisms. DNA, or Deoxyribonucleic Acid, is like a recipe book inside every living thing. It carries instructions that tell our body how to grow, look, and work. These instructions are passed down from parents to children, which is why family members often look alike. DNA is found in tiny parts of our body called cells, and it’s shaped like a twisted ladder, which scientists call a double helix.
- Structure:
- Double helix shape.
- Composed of nucleotides: Adenine (A), Thymine (T), Guanine (G), Cytosine (C).
- Base pairing: A-T, G-C.
- Function: Contains the genetic blueprint for development, functioning, and reproduction.
RNA (Ribonucleic Acid)
RNA is a single-stranded molecule that helps in protein synthesis. RNA, or Ribonucleic Acid, is like a helper for DNA. While DNA stores the instructions for how our body works, RNA helps carry out those instructions. It takes the messages from DNA and helps make the proteins that our body needs to grow, repair, and stay healthy. RNA is like a single strand, not a twisted ladder like DNA.
- Types:
- mRNA (Messenger RNA): Carries instructions from DNA to ribosomes.
- tRNA (Transfer RNA): Brings amino acids to ribosomes for protein synthesis.
- rRNA (Ribosomal RNA): Part of the ribosome structure.
