Question

6) Which of the following is NOT a correct association of amphibian pigment cells? A) Melanophores-brown or black pigment B) Xanthophores orange, yellow, and red pigment C) Chromatophores on the top of the epidermis D) Iridophores-silvery light-reflecting pigment E) All of the choices are correct associations 7) Which is true regarding frog skin? A) The dermis contains chromatophores, which provide skin color. B) The epidermis has mucous glands that secrete mucus to waterproof the skin. C) The epidermis contains keratin. D) The dermis contains large serous glands derived from the inner epidermis that produce a skin poison. E) All of these choices are correct. 8) It grows legs and loses a tail. It changes from an herbivore with a long digestive tract to a carnivore with a shorter one. It loses its gills and lateral line system and uses its skin, mouth, and lungs for gas exchange. What is it? A) Sea squirt larva B) Lancelet C) Tadpole D) Primitive reptile E) Lung-fish 9) Consider the case of some large salamanders that live a long time, produce fewer young, and do not metamorphose into adults without gills, but maintain the juvenile body form as reproductive adults (e.g., hellbender, mudpuppy, sirens). In contrast, "normal" salamanders undergo metamorphosis rather rapidly and have short lives and many young. In what habitat would you expect the large salamanders that retain the juvenile body form to live? A) As salamanders, both types would have exactly the same habitat and evolutionary pressures B) In permanent ponds or streams providing a stable environment C) In temporary ponds with an unstable environment D) In slow-moving streams and rivers with stagnant water E) None of the choices is correct

Answer 1

Q.6ANSWER- E) All the choices are correct combinations because amphibians have a wide array of colors when it comes to skin pigmentation.The pigment of amphibian are determined by specialized cells called chromatophores.There are three types of chromatophores that are important in the coloration of amphibians are:melanophores(contain black or brown pigment from melanin),xanthophores(contain yellow colored pigment) and iridophores(contain reflective or iridescent pigments).

Q.7ANSWER - A,C,D) These options are correct .frog skin have chromatophore which provide skin color to frog skin.The basal layer of the epidermis the stratum germinativum,is composed of columnar or cuboidal cells.these cells are migrating superficially through the stratum spinosum and stratum granulosum layers as they mature,ultimately becoming keratinized in the epidermis.In the frog skin glandular glands with secretions ranging from distasteful to toxic.

Q.8ANSWER - C)Tadpole (larval stage of frog) as they undergo metamorphosis during which they grow limbs,develop lungs,changes herbivorous to carnivorous and reabsorb the tail.

Q.9ANSWER - A)Neotany causes evolutinary modifications due to changes in timing/rate of develpoment.reproduction is seen in what was ancestrally a juenile morphological stages.