Organelle, cell, tissue, organ, organ system, organism.
Answer:
Niche
Explanation:
A niche refers to how an organism responds to different environmental conditions. This conditions could be competitors and how resources are distributed.
Warbler bird's optimum and tolerance requirements for survival, in terms of temperature, precipitation, and food abundance talks about the Niche of the Warbler bird. The ecologist is therefore trying to study the niche of the bird.
The correct answer is A. Between the visceral and parietal layers of serous membranes
Explanation:
Serous fluid is a type of pale yellow fluid similar to mucus that is secreted by certain membranes to reduce friction in body cavities. This can be found on different organs in the body including the digestive system, for example in the peritoneum that encloses multiple organs in the abdomen. Additionally, serious fluid develops between two main layers: the visceral layer that covers the organs and the parietal layer that follows the visceral layer. According to this, serous fluid reduces friction "between the visceral and parietal layers of serous membranes".
All of the above answers are correct.