Answer:
Humans impact the physical environment in many ways: overpopulation, pollution, burning fossil fuels, and deforestation. Changes like these have triggered climate change, soil erosion, poor air quality, and undrinkable water.
The main responsible for the delay among the atrial and
ventricular contractions is the action potential conduction velocity of the AV
node cells. If the atria and ventricles contract simultaneously, atria cannot
give any help in filling the ventricles, which is needed, especially in those
with stiff ventricles as in the elderly. Hence atria have to contract first and
then the ventricles.
Answer:
<h3>Viruses can only replicate themselves by infecting a host cell and therefore cannot reproduce on their own.</h3>
<h3>At the most basic level, viruses consist of genetic material contained within a protective protein coat called a capsid; the existence of both genetic material and protein distinguishes them from other virus-like particles such as prions and viroids.</h3>
<h3>They infect a wide variety of organisms: both eukaryotes (animals, fungi and plants) and prokaryotes (bacteria).</h3>
<h3>A virus that infects bacteria is known as a bacteriophage, often shortened to phage.</h3>
<h3>The study of viruses is known as virology, and those who study viruses are known as virologists.</h3><h3 /><h3>It has been argued extensively whether viruses are living organisms.</h3>
<h3>Most virologists consider them non-living, as they do not meet all the criteria of the generally accepted definition of life.</h3>
<h3>They are similar to obligate intracellular parasites as they lack the means for self-reproduction outside a host cell, but unlike parasites, viruses are generally not considered to be true living organisms.</h3>
<h3>A primary reason is that viruses do not possess a cell membrane or metabolise on their own - characteristics of all living organisms.</h3>
<h3>Examples of common human diseases caused by viruses include the common cold, the flu, chickenpox and cold sores.</h3>
1) Chloroplast
-converts solar energy into food for the plant.
2) Cell Wall
-provides protection and structure.
Answer:
Furthermore, the axial skeleton consists of six parts: the skull, the ossicles of the middle ear, the vertebral column, hyoid, rib cage, and the sternum while the appendicular skeleton consists of limbs and girdles. Axial and appendicular skeleton are the two main parts of the endoskeleton of vertebrates including humans.
Explanation:
