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In insects, growth and metamorphosis are controlled by hormones synthesized by endocrine glands near the front of the body ().Neurosecretory cells in an insect's brain secrete a hormone, the prothoracicotropic hormone (PTTH) that activates prothoracic glands, which secrete a second hormone, usually ecdysone (an ecdysteroid), that induces ecdysis (shedding of the exoskeleton). [7]
Like most insects, the Lepidoptera are oviparous or "egg layers". [40] Lepidopteran eggs, like those of other insects, are centrolecithal in that the eggs have a central yolk surrounded by cytoplasm. The yolk provides the liquid nourishment for the embryo caterpillar until it escapes from the shell. [60]
Lepidoptera (/ ˌ l ɛ p ɪ ˈ d ɒ p t ər ə / LEP-ih-DOP-tər-ə) or lepidopterans is an order of winged insects which includes butterflies and moths.About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organisms, [1] [2] making it the second largest insect order (behind Coleoptera) with 126 families [3] and 46 superfamilies ...
Amphibians, particularly frogs, are among the hardest hit by an extinction crisis, as are insects and reptiles. Frogs are dying off at record rates, an ominous sign the 6th mass extinction is ...
Once wounded, their cells become activated and restore the organs back to their pre-existing state. [13] The Caudata ("urodeles"; salamanders and newts), an order of tailed amphibians, is possibly the most adept vertebrate group at regeneration, given their capability of regenerating limbs, tails, jaws, eyes and a variety of internal structures ...
At the time, third grade teacher, Lynn K. Burgess, and her 1997-1998 class were studying about South Carolina when they found that the state did not have an official state amphibian and decided to ...
The world’s frogs, salamanders, newts and other amphibians remain in serious trouble. A new global assessment has found that 41% of amphibian species that scientists have studied are threatened ...
All but the most primitive caecilians have two sets of muscles for closing the jaw, compared with the single pair found in other amphibians. One set of muscles, the adductors, insert into the upper edge of the pseudoangular in front of the jaw joint. Adductor muscles are commonplace in vertebrates, and close the jaw by pulling upwards and forwards.