<span>The best place to test the pulse is just below the base of the thumb, on the wrist. This allows the person to continue their exercise while still being able to check the pulse rate and see if it has reached the level they are desiring.</span>
Examples of passive transport are osmosis, diffusion, facilitated diffusion and filtration. Hope that'll help.
Answer:
phylum Rhodophyta
Explanation:
Red algae falls under the kingdom Protista and phylum Rhodophyta.
The answer would be the first and second choice because metamorphosis is a very complicated process
Answer:
The 6th Mass Extinction is the current mass extinction event of the Holocene era.
The 6th extinction differs with the last five in terms of the cause. The last 5 extinction events all had natural causes, with species killed either by climate change or by natural disasters such as volcanic eruptions.
Explanation:
Before we elaborate the 6th extinction, it is important to understand the meaning of mass extinction and why it takes place.
Mass Extinction:
<em>A mass extinction is a time period in which a large number of living species go extinct. </em>
The Earth has gone through 5 major extinction events. Lets analyse how their cause differs from the 6th extinction.
- The first extinction occurred in the The Ordovician Period of the Paleozoic Era (about 440 million years ago). The major cause of this event was continental drift and the climate change that followed. This extinction took place in 2 stages: an ice age that covered the Earth and the rising sea levels when the ice age ended.
- The second one occurred in The Devonian Period of the Paleozoic Era (about 375 million years ago). Many climatic changes are suspected to be causes of this event: Lack of oxygen in the oceans, quick cooling of air temperatures, volcanic eruptions, and meteor strikes.
- The third event took place in The Permian Period of the Paleozoic Era (about 250 million years ago). Asteroid strikes, volcanic activity and climate change are suspected to be the causes.
- The fourth extinction occurred at the end of the Triassic Period of the Mesozoic Era (about 200 million years ago). Volcanic activity, rising pH and salt concentrations in the oceans and climate change are said to be the primary causes.
- The fifth extinction occurred at the end of the Cretaceous Period of the Mesozoic Era (about 65 million years ago). Asteroid strikes or meteor showers are said to be the causes.
- The 6th extinction, occurring in the Holocene era, is believed to caused solely by human activities and the consequent climate change.
