Different structures of cells can exist within the same organism. Different structures of cells may be indicative of different organelles presents different structures mostly arise due to different functions of the cell, as how structure of cells always complement the function of cells hence it is most it is mostly likely the last option that the cells have different functions
I do believe it would be the last one in which it describes how how the other species would decline in population size and migrate
Answer:1) medulla to the diaphragm, increasing the rate of breathing
Explanation:
Basically involuntary respiration is controlled by the Respiration centers in the brain Stem. They are group of respiratory neurons ; the dorsal and ventral respiratory groups located in the medulla oblongata , and the pontine respiratory group located in the Pons varolii.
The primary function of this center is for creation and maintenance of respiration rhythms and adjustment of the sequences to fluctuation in body homeostatic balance .
In order to regulate respiration rate and its depth, it collects its input signals from chemoreceptors ( cells that generate biological signals from chemical substances), mechanoreceptors( receptors which relay external physical stimuli of touch, and pressure to internal stimulus by regulation of gated ion channels), the hypothalamus and the cerebral cortex. The fluctuation in the levels of plasma C02, oxygen, and blood pH, stimulated the input progression.
Therefore an elevated C02 blood levels, marked by low pH send input signals to the respiratory centers in the medulla.The latter sends signals to the respiratory muscles (and the diaphragm,) to initiate mechanism of rapid breathing to exhaled more C02 so that the acidity of the blood is reduced..
The cell cycle is divided into the following five stages:
1. Interphase: The cell increase in size. The cell synthesize a complete copy of DNA in its nucleus.
2. Prophase: Chromosomes condense and are more visible. The nuclear membrane disappears. Centrioles separated at move to the opposite poles of the cell. Spindle fibers forms and radiate towards the center of the cell.
3. Metaphase: Chromosomes line up across the middle of the cell. Spindle fibres connect the centromere of each sister chromatid to the cell poles.
4. Anaphase: The centromere that join the sister chromatid split. Sister chromatids separate becoming individual chromosomes and moving to the opposite poles of the cell.
5. Telophase: Chromosomes uncoil. A nuclear envelope forms around each chromosome. Spindle fiber breaks down and dissolves.<span />