Answer:
A polygenic trait can be described as a physical trait which is influenced by more than one gene.
The three types of selection for a polygenic trait are:
1) Directional Selection: In a directional selection, one of the phenotype is favored in an ecosystem. As a result of this favoring, the allelic frequency changes and shifts in favor of this particular trait.
2) Stabilizing selection: It is a type of natural selection in which the intermediate trait is favored. The population carries a middle trait in abundance.
3) Disruptive Selection: Disruptive trait is a type of natural selection in which the traits on the extreme sides are favored. The intermediate traits are less favored.
Answer:
Respiration is a process in which energy is released due to the breakdown of glucose molecules with the addition of oxygen forming carbondioxode, water and energy in the form of Adenine tri phosphate (ATP). In respiration process, carbondioxide is released in the atmosphere and oxygen is used for breakdown of food. This carbondioxide is used by the plants in the process of photosynthesis and oxygen is released in the atmosphere which is again used by animals for respiration.
Answer:
Amount of DNA in a diploid G2 nucleus after S phase has already undergone DNA replication hence the amount of DNA in a diploid nucleus in G1 would be 200 ng. As the organism is diploid, 200 ng of DNA would be carried on 14 chromosomes.
Complex organisms need cells that can perform many different functions. they need to be supported on a cellular level. Without specialized cells you they won't be able to perform different functions.