Genes have two alleles.
Some genes have a variety of different forms, which are located at the same position, or genetic locus, on a chromosome. Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent. Each pair of alleles represents the genotype of a specific gene.
Answer:
is revealed by the degree of similarity in sections of their DNA
Explanation:
phylogenetic analysis of DNA sequences of two different species are compared and the level of similarity between nucleotide sequences in DNA help to identify their relatedness.
Answer:
Inspiration (breathing in)
The diaphragm contracts and moves downwards. The intercostal muscles contract and move the ribs upwards and outwards. This increases the size of the chest and decreases the air pressure inside it which sucks air into the lungs. During normal breathing, the major inspiratory muscles produce rib cage expansion and a downward movement of the diaphragm. These movements cause the pressure around and in the lung to become negative (relative to atmospheric pressure).
Explanation: