D Flashcards
What are the three types of cell division in reproduction?
1) Binary Fission (Prokaryotic organisms, quick but error-prone)
2) mitosis (Eukaryotic organisms used for growth, repair, and asexual reproduction).
3) Meiosis (Used for sexual reproduction, reduces the chromosome number by half).
Binary Fission?
A simple form of cell division in prokaryotes, where the DNA replicates, the cell elongates and then divides into two identical cells.
Mitosis?
A type of cell division in eukaryotic cells that results in two genetically identical diploid cells. Used for growth, repair, and some asexual reproduction.
Steps of Mitosis?
1) Interphase - DNA replication occurs.
2) Prophase - Chromosome becomes visible.
3) Prometaphase - The nuclear membrane breaks apart.
4) Metaphase - Chromosome align at the center.
5) Anaphase - Chromatids are pulled apart.
6) Telophase - Two new nuclei form.
7) Cytokinesis - The cytoplasm splits, forming new cells.
Meiosis?
Type of cell division that results in four haploid cells (gametes or spores) with half the original chromosome number, introducing genetic diversity.
What are the main types of asexual reproduction that use mitosis?
Budding (yeasts, corals, hydras, sponges)
Fragmentation (Flatworms, starfish, molds)
Gemmules (sponges)
Apomixis (Parthenogenesis and Agamospermy in plants).
Fragmentation?
Mode of asexual reproduction where a piece of the organism breaks off and grows into a new individual (ex: starfish, flatworms, algae).
Parthenogenesis?
A type of asexual reproduction where an embryo develops from an unfertilized egg. It can occur via mitotic oogenesis (clonal offspring) or meiotic parthenogenesis (haploid males, ex, bees, ants).
Why does Meiosis increase genetic diversity?
- Independent assortment of Chromosomes
- Crossing over (exchange of genetic material between chromosomes).
- Random Fertilization in sexual reproduction.
What are the three types of gamete sizes?
- Isogamy - Gametes of equal size.
- Anisogamy - One small, one large, both mobile.
- Oogamy - One small and mobile (sperm), one large and immobile (egg).
How are males and females biologically defined?
Males produce small, mobile sperm.
Females produce large, nutrient-rich eggs.
Batemans Principle?
Males maximize their reproductive success by mating with multiple females, while females maximize success by selecting the best mate. However, exceptions exist in nature.
