Frog Reproduction
... Eggs hatch into tadpoles within a few days of fertilization. Tadpoles live off of the yolk of the egg for a few days until the mouth opens and gills are grown. Metamorphosis begins. ...
... Eggs hatch into tadpoles within a few days of fertilization. Tadpoles live off of the yolk of the egg for a few days until the mouth opens and gills are grown. Metamorphosis begins. ...
Reproduction - BiologyUnit2-TSC
... – Why do animals that lay eggs in a terrestrial environment have to invest more in each egg? – What would be the difference between the eggs of r-selected species and K-selected species? – What is the difference between egg-yolk viviparity and placental viviparity? • Would these strategies show r or ...
... – Why do animals that lay eggs in a terrestrial environment have to invest more in each egg? – What would be the difference between the eggs of r-selected species and K-selected species? – What is the difference between egg-yolk viviparity and placental viviparity? • Would these strategies show r or ...
Egg
An egg is the organic vessel containing the zygote in which an animal embryo develops until it can survive on its own, at which point the animal hatches. An egg results from fertilization of an ovum. Most arthropods, vertebrates, and mollusks lay eggs, although some do not, such as scorpions and most mammals.Reptile eggs, bird eggs, and monotreme eggs are laid out of water, and are surrounded by a protective shell, either flexible or inflexible. Eggs laid on land or in nests are usually kept within a favorable temperature range (warm) while the embryo grows. When the embryo is adequately developed it hatches, i.e. breaks out of the egg's shell. Some embryos have a temporary egg tooth with which to crack, pip, or break the eggshell or covering.The largest recorded egg is from a whale shark, and was 30 cm × 14 cm × 9 cm (11.8 in × 5.5 in × 3.5 in) in size; whale shark eggs normally hatch within the mother. At 1.5 kg (3.3 lb) and up to 17.8 cm × 14 cm (7.0 in × 5.5 in), the ostrich egg is the largest egg of any living bird, though the extinct elephant bird and some dinosaurs laid larger eggs. The bee hummingbird produces the smallest known bird egg, which weighs half of a gram (around 0.02 oz). The eggs laid by some reptiles and most fish can be even smaller, and those of insects and other invertebrates can be much smaller still.Reproductive structures similar to the egg in other kingdoms are termed ""spores,"" or in spermatophytes ""seeds,"" or in gametophytes ""egg cells"".