Answer:
By definition, tissues are absent from unicellular organisms. Even among the simplest multicellular species, such as sponges, tissues are lacking or are poorly differentiated. But multicellular animals and plants that are more advanced have specialized tissues that can organize and regulate an organism’s response to its environment.
Answer: <span>femoral; crural
In referring location/region you can use proximal or distal. Proximal means closer to the body. It's the opposite of distal that would mean further to the body
Femoral (or thigh) is located nearer to the body than crural (or leg).</span>
I think its anaerobic respiration
Answer:
B (active transport using ATP)
Explanation:
Movement of substances normally occur in the direction of concentration gradient/difference i.e. the difference in concentration of a substance across a membrane. Letting molecules diffuse or pass down their concentration gradient does not require energy but pumping those molecules against gradient requires energy in form of Adenosine triphosphate (ATP). This process is called Active transport.
In order to perform certain cellular processes, cells need to move substances from their surroundings into the cell across their cell membrane. Moving this substances against the concentration gradient between the cell membrane and its extracellular fluid requires energy (ATP).
An example is the sodium-pottasium pump employed by animal cells in which they expend energy to move K+ molecules into the cell and Na+ molecules outside the cell against the concentration gradient of their cell membrane and extracellular solution.
Answer:
Explanation:
A keystone species is the one which plays an important role in maintaining the structure of the ecosystem. On the keystone species many other species of the ecosystem are dependent upon.
The potential effects associated with the keystone species includes the following:
1. No other species will be capable of filling the same ecological niche. Hence, the dependent organisms will suffer and the ecosystem will change drastically.
2. The ecosystem will be populated by the invasive species which will affects the population of native species.
