NEET Biology Notes Structural Organisation in Animals Frog
Frogs are poikilotherms, have camouflage ability (mimicry). During peak summer and winter, they take shelter in deep burrows- aestivation and hibernation.
- Skin-smooth, slippery absorbs water.
- Body divided into head and trunk, exhibits sexual dimorphism, male frogs can be distinguished by sound producing vocal sacs and copulatory pad present on the first digit of forelimbs.
Anatomy of Frogs
- Digestive system – alimentary canal is short and digestive glands present.
- Respiration – In water, respiration through skin (cutaneous respiration). On land, skin and lungs (pulmonary respiration) both acts as respiratory organs.
- Vascular system – closed type
- Excretory system-consists of a pair of kidneys, ureters, cloaca and urinary bladder, ureotelic animal.
- Control and coordination-Endocrine glands as pituitary, thyroid, thymus, etc., are present and nervous system is well organised.
- Reproduction– Male – a pair of yellowish present testes.
- Female – a pair of ovaries present.
- Fertilisation external in water. Development involves a larval stage called tadpole.