Land animals require more energy since they have to overcome greater inertia during locomotion. Land mammals have adopted many evolutionary mechanisms to support high energy demand.
Heart is four chambered instead of the usual two in aquatic animals like fishes. More number of divisions in heart increases the efficiency of blood circulation process which in turn increases the oxygen delivery rate to cells for producing more energy.
Land mammals also have developed lungs which increase the efficiency of gas exchange process which increases the output of respiration process.
In addition, land mammals also have a strong and developed musculoskeletal system which helps in locomotion.
The parents are of genotype heterozygous dominant and homozygous recessive. Supposing the dominant allele is N and the recessive allele is n, one of the parents will be Nn while the other nn. The phenotypic (based on visible characteristics) ratio will be 1:1 for dom/rec and rec/rec as indicated in the diagram below.
the answer is actually A. chemical weathering by oxidation .
chemical weathering works on rocks that contain iron. These rocks turn to rust in a process called oxidation. Rust is a compound created by the interaction of oxygen and iron in the presence of water.
