In plants, transpiration is a process which is inevitable but potentially harmful, because it can cause loss of water. Loss of water can lead to wilting and eventual death of the plant. Even a little stress can interfere with the plant's growth process.
But, at the same time, transpiration is necessary because of a number of reasons - the transpiration stream aids the processes of mineral absorption, water absorption, energy exchange, helps provide the plant with optimum turgidity, it helps the exchange of gases and so on.
Lancelet is a chordate but not a vertebrate because it lacks a backbone
Explanation:
The subphyla of the phylum Chordata are - Vertebrata, Urochordata and cephalochordate
Those chordates with a structural backbone belong to Vertebrata.
Urochordates and cephalochordates lack a backbone and hence are termed invertebrate chordates.
Lancelet is an invertebrate chordate of the subphylum – Cephalochordata.
The lancelets consist of a notochord that extends right from the head till the tail at the dorsal surface. The notochord acts like the backbone and provides support and a semi-flexible structure to aid in the movement of the organism.
They lack a developed nervous system like vertebrates but only has a dorsal nerve tube
.
Meiosis is important because it ensures that all organisms produced via sexual reproduction contain the correct number of chromosomes.
Fish are cold-blooded or poikilothermic, meaning that their body temperatures vary with the surrounding temperature. During the cold of winter fish become less active. They find little pockets out of the way of fast moving water where they can stay still and conserve energy.
