Reproduction and Development Flashcards
What is the basic premise of sexual reproduction?
The fusion of a male and female gamete forms a diploid zygote
What is the basic premise of asexual reproduction?
Production of offspring without gamete fusion. Can be budding, fission, or fragmentation with regeneration.
What are variations on the mode of reproduction?
Parthenogenesis, hermaphroditism, sex reversal
What controls reproductive cycles?
Hormones and environmental cues
What is fertilization mediated by, whether internal or external?
Pheremones, environmental cues, courtship behavior.
_____ fertilization is associated with fewer offspring and higher survivorship?
Internal
Fertilization brings together the _____ of ______ and ______, forming a _______ zygote that begins development.
nuclei, sperm and egg.
diploid
What prevents polyspermy in many animals?
Changes at the surface of the egg upon sperm entry.
What process follows fertilization and what is it?
Cleavage, a period of rapid cell division without growth, which results in a large number of cells.
In many species, cleavage creates a multicellular ball called the _______, which contains a fluid-filled cavity, the _______
blastula, blastocoel
What is gastrulation?
The conversion of the blastula to the gastrula.
What is the gastrula?
Three germ layers (ecto, meso and endo) with a primitive digestive cavity.
The mammalian zygote develops into a _______ (mammalian blastula) before implantation in the endometrium, what is that?
blastocyst
