The correct answer is option B. The scientists were studying if the mud snails can reproduce both sexually and asexually. The characteristics in the study included parameters such as the mating season, number of offspring, effect of environmental stress conditions and lack of mates. Out of all the parameters being studied can affect asexual reproduction in the mud snail but lack or presence of mates is a parameter required to be studied to determine the mode of reproduction i.e. sexual or asexual because need for mates or mate dependent reproduction occurs in case of sexual reproduction.
Answer:
Vestigial structure. Hope this helps :P
Explanation:
False it is does not have plants it can be release oxygen gas to the atmosphere
Frogs exchange gases through their skin and the lining of their mouths. This exchange of gases is referred to as respiration. During the larval stage in frogs development, it lacks functional lungs but they can take in oxygen through gills which are in process of metamorphosis.
The gills take in oxygen when water is being passed over them. Once lungs are mature, they lose their gills and are able to bring in oxygen through lungs.
They rely on lungs to breath when they are active and they need more oxygen than what skin respiration alone can provide.
Although they have oxygen, most of their respiration occurs through the skin.
