Asexual vs. Sexual Reproduction

• Asexual reproduction involves a single plant or organism producing offspring genetically identical to itself.
• Sexual reproduction involves two parents combining genetic material, creating unique offspring.
• Asexual reproduction is faster, while sexual reproduction creates variation, aiding species survival during environmental changes.

Haploid vs Diploid

• Haploid cells, like sperm and egg cells, contain one set of chromosomes.
• Diploid cells, like most cells in the body, contain two sets of chromosomes (one from each parent).
• Diploid cells have a full set of genetic information, while haploid cells have half.

Types of Asexual Reproduction

• Binary fission: A single-celled organism splits into two identical copies.
• Budding: A new individual develops from a generative point on the parent organism.
• Fragmentation: A simple multicellular organism breaks into two or more pieces upon maturing, each growing into a new organism.
• Vegetative propagation: Plants produce new individuals from various body parts like roots, stems, and leaves.

Asexual vs Sexual Reproduction Advantages/Disadvantages

• Asexual reproduction is faster and more efficient; a single parent rapidly produces offspring without needing a mate or expending energy on gamete production.
• Asexual reproduction results in low genetic diversity, making populations vulnerable to environmental changes, disease, and mutations.
• Sexual reproduction requires more time and energy due to two parents and meiosis/fertilization.
• Sexual reproduction offers increased genetic variation through allele shuffling during meiosis and genetic material combination.
• The variation from sexual reproduction enhances the population's ability to adapt to changing environments.

DNA Structure

• DNA is a double helix: two strands with a sugar-phosphate backbone on the outside.
• DNA molecules have 4 nucleotides arranged in a repeated fashion.

Somatic Cells vs Gametes

• Somatic cells have two sets of chromosomes, providing full genetic instructions.
• Gametes are sex cells with only one set of chromosomes and are haploid.
• Somatic cells have double the number of chromosomes.

Genetic Definitions

• Gene: A DNA section containing instructions to make a specific protein.
• Allele: A different version of a gene, inherited in pairs (one from each parent), which may be identical or different.
• Genome: A complete DNA sequence of an organism, including genes determining traits, elements controlling gene expression, and contributing to development/function.
• Locus: A gene's specific position on a chromosome.
• Homologous Pairs: Chromosomes with similar length, gene sequence, and centromere location, inherited one from each parent.
• Homozygous: Same alleles (AA, aa).
• Heterozygous: Two different alleles, one dominant (Aa).
• Phenotype: Observable characteristics of an organism, resulting from genotype expression and environmental influences (e.g., eye color, height).
• Genotype: A specific combination of alleles an individual has for a particular gene or set of genes.

Variation

• Variation is due to inherited genes (genetic causes), environmental conditions, or a combination.
• Variation is crucial for long-term survival/adaptability, arising from allele differences and leading to diverse phenotypes.
• Variation allows populations to respond to environmental pressures (e.g., disease, climate change).
• Individuals with advantageous traits are likely to survive/reproduce, passing on beneficial alleles ("natural selection").

Mitosis

• Two new daughter cells are genetically identical to the parent and have a normal number of chromosomes (diploid-2n).

Meiosis

• Four new daughter cells are produced and are not genetically identical to the parent cell or each other; they each have half the number of chromosomes (haploid-n).
• Half of the 46 chromosomes are maternal (from the mother), and half are paternal (from the father).

Mitosis Cell Cycle

• Interphase: The cell spends most of its time in interphase, growing and performing its functions.
• During interphase, chromosomes duplicate, cell organelles replicate, enzymes are produced, energy (ATP) is produced, and new proteins are made.
• Before the cell divides (towards the end of interphase) the genetic information for the cells needs to be replicated so that new cells contain the same information.
• Prophase: DNA condenses into chromosomes, spindle fibres form at opposite poles, and the nuclear membrane disappears.
• Metaphase: Double-stranded chromosomes line up along the cell's center, and spindle fibres attach to the centromere of each chromosome.
• Anaphase: Spindle fibres pull the chromatids apart to opposite sides of the cell.
• Telophase: New nuclear membranes form around separated chromatids, and the cytoplasm divides.
• Two new nuclei form with a diploid number of chromosomes.
• Cytokinesis: The cytoplasm of the parent cell divides into two daughter cells.
• New cell membranes form.

Mitosis vs. Meiosis

• Mitosis occurs in all organisms (except viruses) and creates all body (somatic) cells.
• Meiosis only occurs in plants, animals, and fungi and creates only sex (germ) cells.
• Mitosis involves one cell division, while meiosis involves two successive cell divisions.
• Mitosis produces two diploid daughter cells, while meiosis produces four haploid daughter cells.
• Mitosis daughter cells are genetically identical while meiosis daughter cells are genetically different.
• Mitosis creates a human cell with 46 chromosomes while meiosis creates a human cell with 23.