Biology 1201A Lecture Notes - Lecture 10: Fetus, Thymine, Sporophyte
Document Summary
No dominant diploid or haploid phase: some plants have short haploid phase, others have longer phase (same with diploid) Plants create spores - makes more cells, remain haploid to create a multicellular haploid plant > called gametophyte. From gametophyte > divide by mitosis and separate into sperm and egg > get fertilized > create zygote. Mosses: haploid phased dominant, green part - gametophyte (n, brown part - sporophyte (2n) Fungi - hardly any diploid phase: as soon as zygote is formed -> divide by mitosis, multicellular gametophyte - dominant. Phenotype - determined by genotype or environment. Most are neutral - no effect on fitness. No variation > doomed to failure, any change to environment/diseased > spread all throughout population. We need diversity, variation for a population to survive in changing environments. If it"s not controlled - cancer > unregulated cell growth. Mejocytes - cells that will undergo meiosis. Effect of gremlin mutations not apparent in the parent.
