Unit 4: Reproductive Strategies Flashcards
Reproductive strategies:
-the human life cycle relies on regular patterns of meiosis and mitosis. However, other organisms rely on alternative reproductive strategies.
- Binary fission:
•method of reproduction utilized by bacteria.
•allows for rapid growth of identical populations through asexual reproduction.
- Conjugation:
•also utilized by bacteria.
•plasmids (DNA source) are transferred from one cell to another through pili.
•creates cells with new genetic combinations (sexual reproduction).
- Budding:
•a form of asexual reproduction in which a complete but miniature version of the parent grows out from the parent’s body; the newly formed clone separates only once it matures.
•commonly utilized by metazoans such as corals, sponges, and hydra.
- Vegetative reproduction:
•a form of budding that takes place in plants (asexual reproduction).
•new plant develops at the end of each stem.
•once new plant takes root, the stem disintegrates and separates the new plant from the parent.
- Parthenogenesis:
•a form of asexual reproduction in which an unfertilized egg develops into an adult.
- Spores:
•form of asexual reproduction which allows parents to disperse their offspring over long distances.
•may be haploid or diploid.
•some spores are actually the product of sexual reproduction (meiosis rather than mitosis), resulting in an alternation of generations.
Alternation of generations:
•the life cycle of some plants consists of two generations:
1. A diploid generation, or sporophyte.
2. A haploid generation, or gametophyte.
i. Through meiosis, the sporophyte (or spore-making body) produces multiple haploid spores.
ii. Haploid spores spread and develop without fertilization.
iii. Each spore grows into a plant body called the gametophyte (or gamete-making body), which produces male and female gametes.
iv. Upon fertilization, gametes develop into another sporophyte, and the cycle repeats.
Sporophyte:
-makes spores.
Spore =
•n (haploid).
Gametophyte:
-makes gametes.
