Answer:
Genetic drift
Explanation:
Genetic drift can also be referred to as allelic drift, it refers to the variation in allelic frequencies within a particular population over a period of time. It can also be referred to as the random fluctuations in the number of genotypes within a population. Genetic drift is not influenced by the environment and is usually more pronounced in a small population of organisms.
For example, a population of birds can consist of green feathers and blue feathers with the green feathers as the dominant allele, but as a result of random fluctuations, the offspring may all be with green feathers and hence could eliminate or reduce the allele responsible for blue feathers over time.
Adaptation is the tendency of some members of a population to be better able to survive and reproduce and pass on their characteristics.
Answer:
Option (A) and (D).
Explanation:
Esophagus may be defined the long tube like structure that connect the throat with the stomach. The partially digested food from the buccal cavity to the stomach is pass down through the esophagus.
The mucosa of the esophagus contains the thick layer of the nonkeratinized squamnous epithelium. The smooth muscles are present in some layers only. The two layer of the muscle that are superior to the one third of the muscularis are the skeletal muscle.
Thus, the correct answer is option (A) and (D).
Why temperature affects heart rate in ectothermic organisms? If the temperature is within the optimal range for enzyme activity more ATP will be produced and the heart will beat faster due to increased metabolic activity and energy availability.
Circulatory system and nucleus
