Genetics is the scientific study of heredity and inherited variations. Offspring acquire genes from parents through the inheritance of chromosomes. Sexual reproduction combines genes from two parents, leading to genetically diverse offspring. Meiosis produces haploid gametes with one set of chromosomes through two cell divisions in the ovaries and testes. During fertilization, the egg and sperm unite forming a zygote that develops into a multicellular organism through mitosis.

1. Genetics
• Genetics is the scientific study of heredity and
inherited variations.
• The transmission of traits from one generation
to the next is called inheritance or heredity
• offspring acquire genes from parents by
inheriting chromosomes
• In asexual reproduction, a single parent
produces genetically identical offspring by
mitosis
• Sexual reproduction combine genes from two
parents, leading to genetically diverse
offspring

2. Meiosis
• Normal human somatic cells are diploid. They have 46
chromosomes made up of two set of 23, one set from
each parent
• Human diploid cells have 22 pair of homologs that are
autosomes, and one pair of sex chromosome
• Homologous chromosomes carry genes controlling the
same inherited characters
• In human ovaries and testes produce haploid gametes
by meiosis, each gamete containing a single set of 23
chromosomes
• During fertilization, an egg and sperm unite forming a
diploid single celled zygote
• Zygote develops into a multicellular organism by
mitosis

3. Meiosis
• The two cell division of meiosis, meiosis I and meiosis II
produce four haploid daughter cell
• The number of chromosome sets is reduced from 2n to n in
meiosis I
• The second meiotic division separates sister chromatids

4. Meiosis

5. Mitosis Vs Meiosis

6. Genes
• DNA is the genetic blueprint which codes for, and determines the
characteristics of an organism
• DNA is packaged and organized into discrete structures called
chromosome
• A gene is a sequence of DNA that encodes for a specific trait
• The position of gene on a particular chromosome is called the
locus

7. Alleles
• Alleles are alternative forms of a gene that code for the different
variations of a specific trait
• Alleles only differ from each other by one or a few bases