Q. Heart is absent in
NTA AbhyasNTA Abhyas 2020
Solution:
Earthworm does no longer has a real heart as it is an invertebrate, however, refers to them as the heart because they have 5 pairs of aortic arches. Those arches are present within the anterior place of the frame and that they join ventral and dorsal vessels and pump blood at some point of the frame.
Cephalochordates have a closed circulatory system (the blood is enclosed in blood vessels) but lack an imperative pump (coronary heart). As an alternative, the blood is propelled with the aid of pulsation (rhythmic contraction and rest) of several blood vessels. Example: Amphioxus.
Annelids do no longer have an imperative, well-evolved coronary heart, and commonly the muscular dorsal blood vessel features to pump blood via the circulatory system. In a few species, there may be some muscular blood vessels that function as blood-pumping hearts. Example: Nereis.
Cephalochordates have a closed circulatory system (the blood is enclosed in blood vessels) but lack an imperative pump (coronary heart). As an alternative, the blood is propelled with the aid of pulsation (rhythmic contraction and rest) of several blood vessels. Example: Amphioxus.
Annelids do no longer have an imperative, well-evolved coronary heart, and commonly the muscular dorsal blood vessel features to pump blood via the circulatory system. In a few species, there may be some muscular blood vessels that function as blood-pumping hearts. Example: Nereis.