CELL BIOLOGY AND GENETICS NOTES
CELL BIOLOGY
Definition:
Cell biology is the study of the structure and function of cells, which are the basic units of life.
Types of Cells:
• Prokaryotic cells – lack a true nucleus (e.g. bacteria)
• Eukaryotic cells – have a true nucleus (plant and animal cells)
Cell Organelles and Functions:
• Cell membrane – controls entry and exit of substances
• Nucleus – controls cell activities, contains DNA
• Mitochondria – energy production (ATP)
• Ribosomes – protein synthesis
• Endoplasmic reticulum – transport and synthesis
• Golgi apparatus – modifies and packages proteins
• Lysosomes – digestion and waste removal
• Vacuole – storage
• Chloroplast – photosynthesis (plants)
• Cell wall – support and protection (plants)
Cell Division:
• Mitosis – growth and repair of tissues
• Meiosis – formation of gametes and genetic variation
GENETICS
Definition:
Genetics is the study of heredity and variation in organisms.
Key Genetic Terms:
• Gene – unit of inheritance
• DNA – genetic material
• Chromosome – structure carrying genes
• Allele – alternative form of a gene
• Genotype – genetic makeup
• Phenotype – physical expression
Structure of DNA:
• Double helix structure
• Made up of nucleotides (sugar, phosphate, base)
• Bases: Adenine, Thymine, Guanine, Cytosine
Mendelian Inheritance:
• Law of segregation
• Law of independent assortment
• Dominant and recessive traits
Non-Mendelian Inheritance:
• Incomplete dominance
• Codominance (e.g. blood groups)
• Sex-linked traits
Gene Expression:
• Transcription – DNA to RNA
CELL BIOLOGY
Definition:
Cell biology is the study of the structure and function of cells, which are the basic units of life.
Types of Cells:
• Prokaryotic cells – lack a true nucleus (e.g. bacteria)
• Eukaryotic cells – have a true nucleus (plant and animal cells)
Cell Organelles and Functions:
• Cell membrane – controls entry and exit of substances
• Nucleus – controls cell activities, contains DNA
• Mitochondria – energy production (ATP)
• Ribosomes – protein synthesis
• Endoplasmic reticulum – transport and synthesis
• Golgi apparatus – modifies and packages proteins
• Lysosomes – digestion and waste removal
• Vacuole – storage
• Chloroplast – photosynthesis (plants)
• Cell wall – support and protection (plants)
Cell Division:
• Mitosis – growth and repair of tissues
• Meiosis – formation of gametes and genetic variation
GENETICS
Definition:
Genetics is the study of heredity and variation in organisms.
Key Genetic Terms:
• Gene – unit of inheritance
• DNA – genetic material
• Chromosome – structure carrying genes
• Allele – alternative form of a gene
• Genotype – genetic makeup
• Phenotype – physical expression
Structure of DNA:
• Double helix structure
• Made up of nucleotides (sugar, phosphate, base)
• Bases: Adenine, Thymine, Guanine, Cytosine
Mendelian Inheritance:
• Law of segregation
• Law of independent assortment
• Dominant and recessive traits
Non-Mendelian Inheritance:
• Incomplete dominance
• Codominance (e.g. blood groups)
• Sex-linked traits
Gene Expression:
• Transcription – DNA to RNA
