Answer:
The animals present body structure is due to evolution. It is seen in each part including the structure of the heart. The vertebrate heart becomes complex from a simpler form.
Invertebrates, the heart of fishes is two-chambered having one auricle and one ventricle. The deoxygenated blood gets purified in the gills. They are aquatic and no lungs for breathing. The hearts pump a mixture of oxygenated and deoxygenated blood to the body.
The amphibians and reptiles have 3 chambered heart as they lead terrestrial mode of life. The gills modified into the lungs. The left auricle receives pure blood and the right auricle receives deoxygenated blood. The blood purified in the lungs and in the ventricle, both types of blood get a mix. The ventricle pumps the mixed-blood throughout the body.
In the case of birds and mammal, the heart is 4 chambered and the oxygenated and deoxygenated blood are separated. These two are higher vertebrates. No mix of pure and impure blood, the body receives only the oxygenated blood.
This shows to construct the phylogenetic tree of vertebrates - the fishes should be in the bottom, and above it amphibians, reptiles, then, mammals and birds on the top branch of the tree. As the chambers and structure of the hearts modified one after another.
The greatest amount of genetic variation is a sexual population is due to the processes of meiosis and mutation. Meiosis increases the genetic variation because of the recombination and independent assortment in the process, such that each gamete contains a different set of DNA, therefore the zygote produced during fertilization has a unique combination of genes.<span />
I believe that the term metabolic rate reflects the energy the body needs to perform only its most essential activities. It is the rate of energy expenditure per unit time by endothermic animals while at rest, or the amount of energy that a person need to maintain the body functions while at rest per unit time.
Genotype
DEFINITION
IT IS THE GENETIC MAKEUP OF THE CELLS.
Phenotype
DEFINITION
IT IS PHYSICAL APPEARANCE OF ORGANISMS.
The Genotype, carried by all living organisms, holds the critical instructions that are used and interpreted by the cellular machinary of the cells to produce the r Phenotype of the organism.
Thus, all the physical parts, the molecules, cells and other structures, are built and maintained by cells following the instructions give by the genotype.
The correct answer is Streptococcus.
Glomerulonephritis (GN) is inflammation of the glomeruli and may be acute or chronic. Acute glomerulonephritis can be a response to an infection (immune system overreacts to the infection) such as strep throat which is caused by group A Streptococcus bacteria.
