Question: The hypotha mus-pituitary-gonad (HPG) axis regulates the reproductive success of all vertebrates…
Show transcribed image text The hypotha mus-pituitary-gonad (HPG) axis regulates the reproductive success of all vertebrates. It is influenced by a variety of internal [i.e. hormones and other bioregulators) and external es such as temperature, photoperiod, and pheromories. The HPG axi of non-mammals operated essentially like that of mammals. Attainment of sexual maturity occurs at a time characteristic for each species and is followed by a series of reproductive cycles closely attuned to certain environmental factors. Bony fishes illustrate the full range of reproductive strategies known for vertebrates. Depending on the species, sexual matu may be achieved during the first year of life (many teleosts), after more than 15 years of juvenile existenced (Atlantic eel, sturgeon) or at some intermediate period. Some animals are s parous and breed only once after a aining sexual maturity and die soon afterwards (for example, Pacific salmon, Onco hynchus spp), whereas most species are iteroparous and exhibit two or more reproductive cyles. Some of these may produce successive broads in a given year or season or may exhibit only one or two cycles per year. A few species may breed as one sex and then change to the opposite sex and breed again. Males may exhibitg an associated reproductive pattern in which gonadal steroids are highest during mating or a dissociated reproductive pattern where mating occurs when androgens are reduced. 1. Apart from the factors named in this passage, what other factors do you know that will affect the attainment of sexual maturity in animals. You can use the human as an example? 2. From the passage what can you deduce as the difference between semelparous and iteroparous organisms? 3. What is the appropriate term for reproductive cycles in primate mammals and non-primate mammals (such as rat, rabbit etc) respectively?
The hypotha mus-pituitary-gonad (HPG) axis regulates the reproductive success of all vertebrates. It is influenced by a variety of internal [i.e. hormones and other bioregulators) and external es such as temperature, photoperiod, and pheromories. The HPG axi of non-mammals operated essentially like that of mammals. Attainment of sexual maturity occurs at a time characteristic for each species and is followed by a series of reproductive cycles closely attuned to certain environmental factors. Bony fishes illustrate the full range of reproductive strategies known for vertebrates. Depending on the species, sexual matu may be achieved during the first year of life (many teleosts), after more than 15 years of juvenile existenced (Atlantic eel, sturgeon) or at some intermediate period. Some animals are s parous and breed only once after a aining sexual maturity and die soon afterwards (for example, Pacific salmon, Onco hynchus spp), whereas most species are iteroparous and exhibit two or more reproductive cyles. Some of these may produce successive broads in a given year or season or may exhibit only one or two cycles per year. A few species may breed as one sex and then change to the opposite sex and breed again. Males may exhibitg an associated reproductive pattern in which gonadal steroids are highest during mating or a dissociated reproductive pattern where mating occurs when androgens are reduced. 1. Apart from the factors named in this passage, what other factors do you know that will affect the attainment of sexual maturity in animals. You can use the human as an example? 2. From the passage what can you deduce as the difference between semelparous and iteroparous organisms? 3. What is the appropriate term for reproductive cycles in primate mammals and non-primate mammals (such as rat, rabbit etc) respectively?
