Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Circulation Patterns
All vertebrates have some similarities in their circulatory systems but as vertebrate life changes from aquatic to terrestrial, the pattern of circulation becomes more complex. Fish and mammals represent two extremes in vertebrate circulation and Fig. 3.6 compares the two. The principal difference is in heart structure, from two chambered in fish to four chambered in mammals. The fish heart contains two main chambers in series the atrium or auricle and the ventricle. There are two subsidiary chambers (not shown in Figure) the sinus venosus which proceeds the atrium and conus arteriosis which comes after the heart.
These contain valves that prevent backwards flow of blood. Blood makes a single circuit from the heart to the gills where it is' oxygenated and then to the dorsal aorta to be distributed to the body from where it returns to the heart by the veins. Such a system has the advantage that all of the blood going to the body has already been oxygenated in the gills. However, there is a disadvantage i.e. the narrow gill capillaries slow down the blood flow resulting in a low blood pressure. This slows the rate of oxygen delivery to the cells and limits the metabolic rate that fish can attain.
Figure: Circulatory system pattern in (a) fish and (b) mammals. Rust shows oxygenated blood
What is the evolutionary advantage of the occurrence of sperm cells and larval stage in the life cycle of sponges? The sexual reproduction in sponges, in addition to contributi
human genome project
significance of gastrulation
Hemicellulose In plant cell walls, the most abundant compound present is α-cellulose with long fibers embedded in a matrix of cementing compounds (matrix polysaccharides). Thes
What is the name of the cytoplasm division in the end of mitosis? What are the differences in this process between animal and plant cells? Cytoplasm division happens after telo
what is its working
What is the structural representation of a carboxyl group? Carboxyl groups have a carbon attached to single hydroxyl group by a simple bond and to one oxygen by a double bond.
What is the function of the iris and of the pupil? The iris works like the diaphragm of a photographic camera as it has muscles that contract or relax varying the pupil diamete
Q. Why can the genetic code be qualified as a "degenerate code"? The genetic code is a degenerate code because there are amino acids codified by more than one type of codon, it
Q. What are Zoonotic Diseases? The World Health Organization defines Zoonoses (Zoonosis, sing.) as "Those diseases and infections, which are naturally transmitted between verte
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd