Human evolution known to be a process in which species adapt to certain conditions of life, and in the battle of life and death, they are forced to become stronger in order to survive in the world. Diseases have always been present during the evolution, acting themselves as a natural selector-the weaker organisms get sick and die.
Answer:
A. Lancelet
B. All chordates
Explanation:
A. Dorsal nerve chord is the only <u>unique feature</u> among all members of <u>phylum chordata</u> (mainly found in subphylum Vertebrata). In the given list, only lacelet is the Chordate whereas <u>snail belongs to phylum Mollusca</u>, <u>grasshopper belongs to Arthropda</u>, and <u>jellyfish belongs to Cnidaria</u>. Dorsal nerve cord runs along the length of organism's body.
B. <u>Gill slits</u> are <u>opening structures</u> to gills through which water passes from pharynx/throat to exterior. Their main purpose is to help filter the food particles available in surrounding water. Although they are typical for amphibians and fishes, chordates also possess gill slits at embryonic stages.
A descriptive observation may very well be a mixture of both quantitative and qualitative as it can utilize elements of both types. Qualitative deals with the kinds of observations that cannot be measured in numerical form. Quantitative data is just that.
Answer:
Vertebrates contain nervous system which is highly specialized organ.
Explanation:
The nervous system is the complex system in the vertebrate body which is composed of central nervous system that contain brain,spinal cord and peripheral nervous system which contain cranial nerve, spinal nerve,involuntary nerve etc.
The nervous system contain neurons that mainly transmit signal to the different parts of the body.
The peripheral nervous sytem contain somatic and visceral part.
The grey matter and white matter are the 2 areas in vertebrate nervous system.
