Genetics in Class 12 Biology:

Introduction:
Genetics is the study of heredity and variation in living organisms. It involves the study of genes, their functions, and how they are passed down from one generation to the next.

Mendelian Genetics:
Mendelian genetics is based on the work of Gregor Mendel, an Austrian monk who studied pea plants. He discovered the laws of inheritance, which state that traits are passed down from parents to offspring in predictable patterns.

Chromosomal Theory of Inheritance:
The chromosomal theory of inheritance states that genes are located on chromosomes and are passed down from one generation to the next through the process of meiosis and fertilization.

DNA and Gene Expression:
DNA is the genetic material that contains the instructions for the development and function of all living organisms. Gene expression is the process by which genes are turned on or off, and it plays a crucial role in determining an organism's traits.

Genetic Disorders:
Genetic disorders are caused by mutations in genes or chromosomes. They can be inherited from one or both parents, or they can occur spontaneously.

Human Reproduction, Class 12 Biology:

Introduction:
Human reproduction is the process by which offspring are produced. It involves the fusion of male and female gametes to form a zygote, which develops into a fetus.

Male Reproductive System:
The male reproductive system includes the testes, epididymis, vas deferens, seminal vesicles, prostate gland, and urethra. These structures produce, store, and transport sperm.

Female Reproductive System:
The female reproductive system includes the ovaries, fallopian tubes, uterus, cervix, and vagina. These structures produce and transport eggs, provide a site for fertilization, and support the development of the fetus.

Menstrual Cycle:
The menstrual cycle is the regular, monthly cycle of changes that occur in the female reproductive system. It is regulated by hormones and involves the shedding of the uterine lining, ovulation, and the preparation of the uterus for pregnancy.

Fertilization and Pregnancy:
Fertilization occurs when a sperm cell fuses with an egg cell to form a zygote. The zygote develops into a fetus, which is supported by the mother's uterus and placenta.

Childbirth and Lactation:
Childbirth is the process by which a baby is born. It involves the contraction of the uterus and the expulsion of the fetus. Lactation is the process by which a mother produces milk to feed her baby.