● Frog has different types of `color{violet}("sense organs")`, namely `color{violet}("organs")` of touch ( `color{brown}("sensory papillae")` ), taste ( `color{brown}("taste buds")`), smell ( `color{brown}("nasal epithelium")`), vision ( `color{brown}("eyes")`) and hearing ( `color{brown}("tympanum with internal ears")`).

● Out of these, eyes and internal ears are `color{brown}("well-organised structures")` and the rest are `color{violet}("cellular aggregations")` around nerve endings.

`star` `color{green}("Eyes:")`

● `color{violet}("Eyes")` in a frog are a pair of `color{violet}("spherical structures")` situated in the `color{violet}("orbit in skull.")`

● These are `color{brown}("simple eyes")` (possessing only one unit).

`star` `color{green}("Ear:")`

● `color{violet}("External ear")` is absent in frogs and only `color{brown}("tympanum")` can be seen externally.

● The ear is an `color{violet}("organ")` of hearing as well as balancing ( `color{brown}("equilibrium")`).

● `color{violet}("Frogs")` have well organised male and female `color{violet}("reproductive systems.")`

`star` `color{green}("Male Reproductive Organs :")`

● `color{violet}("Male reproductive organs")` consist of a pair of `color{brown}("yellowish ovoid testes,")` which are found adhered to the upper part of kidneys by a double fold of peritoneum called `color{brown}("mesorchium.")`

● `color{brown}("Vasa efferentia")` are 10-12 in number that arise from testes.

● They enter the `color{violet}("kidneys")` on their side and open into `color{brown}("Bidder’s canal.")`

● Finally it communicates with the `color{brown}("urinogenital duct")` that comes out of the `color{violet}("kidneys")` and opens into the `color{violet}("cloaca.")`

● The `color{brown}("cloaca")` is a small, median chamber that is used to pass `color{violet}("faecal matter, urine")` and `color{violet}("sperms")` to the exterior.

`star` `color{green}("Female Reproductive Organs:")`

● The `color{violet}("female reproductive organs")` include a `color{brown}("pair of ovaries.")`

● The `color{violet}("ovaries")` are situated near `color{violet}("kidneys")` and there is no functional connection with `color{violet}("kidneys.")`

● A `color{brown}("pair of oviduct")` arising from the ovaries opens into the `color{violet}("cloaca separately.")`

● A `color{violet}("mature female")` can lay 2500 to 3000 ova at a time.

● Fertilisation is `color{violet}("external")` and takes place in water.

● `color{violet}("Development involves")` a larval stage called `color{brown}("tadpole.")`

● `color{violet}("Tadpole")` undergoes `color{brown}("metamorphosis")` to form the adult.

● `color{violet}("Frogs")` are beneficial for mankind because they eat insects and protect the crop.

● Frogs `color{brown}("maintain ecological balance")` because these serve as an important link of `color{violet}("food chain and food")` web in the `color{violet}("ecosystem.")`

● In some countries the `color{violet}("muscular legs")` of `color{violet}("frog")` are used as `color{violet}("food by man.")`