Because whales live in the ocean, many people think they are fish. But do you know that whales and dolphins are not fish? They are mammals. People are mammals too. Mammals are the group of animals that breath air using lungs, give birth to live young (rather than laying eggs), and feed their young with mother’s milk. All animals, including people, need oxygen, a chemical found in the air and in water. Fish use their gills to take oxygen from the water that they live in. But people get the oxygen we need by breathing air, using our lungs. Whales and dolphins use their lungs to breathe air also.
That’s one reasons why they come to the surface of the ocean. Sometimes they lie right at the surface of the water, with just a part of their back sticking out. Look closely at a picture of a whale or dolphin; can you see a nose on the whale? You can’t, because whales don’t have noses like you and me. Instead they have a hole – called a “blow hole” – on top of their heads. Sometimes when a whale breathes air out of its blow hole, it shows up as a spray or mist – called a “spout” – that can be seen many miles away. Blow holes are surrounded by muscles that keep the hole closed when the whale or dolphin is under water and open it when the animal is at the surface and needs to breathe.
In fact, some of the animals have two blow holes next to each other and others have only one. So when you see a picture of a whale, see if you can tell the difference. Pilot whales and dolphins have one blow hole; humpbacks, minkes and right whales have two
With ideal environmental factors, bacteria are able to reproduce at a very rapid pace.
<h3>Bacterial reproduction</h3>
Bacteria reproduce mainly by a single cell dividing into two, given the right condition. In order words, they reproduced by binary fission.
When environmental conditions are optimum, a typical bacterial cell can divide every 4 to 20 minutes depending on the species.
The time can become longer with sub-optimal environmental conditions.
More on bacterial reproduction can be found here: brainly.com/question/600239
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The gourth one best supports
defends body against infections so probobly secreting enzymes
Uses natural pressure
Has groundwater stuck between impermeable layers
are the statements which describe the attributes of an Artesian well.
<u>Explanation</u>:
- Artesian well, well from which water is pumped under natural pressure without pumping. It is dug or dug wherever a soft dip, porous rock layer obtains water along its ridge at a point higher than the rate of the ground surface at the well site
- .First, artesian groundwater is the same as any other groundwater type; the only distinction is how it reaches the surface.
- An artesian well is simply a well that doesn't involve a pump to get water to the surface it happens when there is sufficient pressure in the aquifer. This gives rise to positive pressure.
