The answer is 44 chickens and 28 rabbits.
We have a system of two equations.
x - the number of rabbits
y - the number of chickens
Both chicken and rabbit have only 1 head, so the first equation is: x + y = 72.
Since rabbits have 4 legs and chickens 2 legs, the second equation is: 4x + 2y = 200.
Now, let's solve the system:
x + y = 72
4x + 2y = 200
___________
y = 72 - x
⇒ 4x + 2 · (72 - x) = 200
4x + 2 · 72 - 2 · x = 200
4x + 144 - 2x = 200
2x + 144 = 200
2x = 200 - 144
2x = 56
⇒ x = 56 ÷ 2 = 28
So, there are 28 rabbits.
Since
y = 72 - x = 72 - 28 = 44,
there are 44 chickens.
Answer:Amphibians evolved during the middle of the Devonian period (416 to 359 million years ago) from the lobe-finned fish of the vertebrate class Sarcopterygii. Species within the genus Ichthyostega (members of the Labyrinthodontia subclass) are considered by some scientists to be the earliest amphibians.
Explanation:
Answer:
<u>-blue and red light</u>
Explanation:
Plants produce sugars or carbohydrates during the process of photosynthesis. They absorb light energy from the electromagnetic spectrum with pigments within the thylakoid membrane, like chlorophyll a, chlorophyll b.
Chlorophylls are made of ringed molecules chlorine, a hydrogenated form of porphyrin with a magnesium ion bonded to four atoms of nitrogen. Chlorophyll a shows the most absorption of red light (642 nm) and blue light (372 nm); while chlorophyll b shows the most absorption at 626 nm and 392 nm.
Different types of chlorophyll sidechains change the molecules' absorption ranges; A's methyl group is bound at carbon 7, B's aldehyde (CHO) ring is bound at carbon 7. Both absorb light from orange-red and violet-blue wavelengths. As such, the best light wavelengths for photosynthesis are within the blue and red wavelengths (425–450 nm) and (600–700 nm).
Answer: It is important that we use our natural resources so that we use any bad things for our earth
Explanation:
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The answer is <span>Cyanobacteria are photoautotrophs.
</span><span>Cyanobacteria /saɪˌænoʊbækˈtɪəriə/, also known as Cyanophyta, is a phylum of bacteria that obtain their energy through photosynthesis. The name "cyanobacteria" comes from the color of the bacteria.</span>