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4 years ago

explain why the top of an energy pyramid does not have an arrow showing energy going back down to the bottom.

2 answers:

4 0

The answer to your question is that all of the energy is ultimately radiated into empty outer space as heat. The second law of thermodynamics mandates that all processes that involve the transfer of energy MUST radiate a portion of this energy into space as waste heat. This is why when you run down the street you get hot and sweaty, and this is why automobiles MUST have a functioning radiator and nuclear power stations MUST have evaporation cooling towers or else be located near a large body of water to exchange excess waste heat into, etc., etc. It is also true that the transfer of energy at each step up the food chain is very inefficient. They say it takes around 50 lbs of corn to produce one pound of beef, and it probably takes 20-30 pounds of beef to produce one pound of human tissue. The rest of the energy just goes into your living room as radiated body heat. I hope this helps.

Nostrana [21]4 years ago

4 0

Energy does not go back to the bottom of the pyramid. Energy is used by the organisms in that level or passed on to decomposers when the animals die. Some of the energy is lost to the atmosphere as heat from the animal's body.

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Black fur is dominant to white fur in guinea pigs. If two guinea pigs (Bb) are crossed what color and in what percentage What is

mote1985 [20]

I believe that the odds are strong that the off-spring would be 1/4 black, 1/2 black and white, and 1/4 white:

Bb x Bb = ¼ BB (all black); ½ Bb (black and white ) ;¼ bb (all white).

4 0

3 years ago

Put the steps of zygomycete sexual reproduction in the right order. Start with the production of multinucleate gametangia at the

Vesnalui [34]

Answer:

Choice 4 of 5. Hyphae produces multinucleate gametangia

Choice 1 of 5. Gametangia fuse

Choice 2 of 5. Karyogamy occurs and zygosporangium develops

Choice 5 of 5. A dark, thick-walled zygospore develops

Choice 3 of 5. Meiosis occurs to produce haploid spores

Explanation:

The steps of zygomycota sexual reproduction are;

Germination step; Hyphae produces multinucleate gametangia

Plasmogamy step; Gametangia fuse when compatible mating types of mycelia are brought close to each other by the formation gametangia between

The fusion of the nuclei results in the formation of zygosporangium that has multiple haploid nuclei and a thick wall

Karyogamy step; A zygote having multiple diploid nuclei is formed by the fusion of nuclei

Germination and Meiosis step; The sporangia grows and haploid spores are produced

Therefore, we have;

Choice 4 of 5. Hyphae produces multinucleate gametangia

Choice 1 of 5. Gametangia fuse

Choice 2 of 5. Karyogamy occurs and zygosporangium develops

Choice 5 of 5. A dark, thick-walled zygospore develops

Choice 3 of 5. Meiosis occurs to produce haploid spores

3 0

3 years ago

Plz can anyone write an essay about water pollution about 1300 words

AysviL [449]

Answer:

Explanation:

The biological or chemical change in the quality of water due to the presence of contaminants in water is called water pollution. Most of this contamination as on date is due to various human activities. In fact, humans are responsible for the mass deaths of whales and other aquatic organisms often swept ashore at different beaches in the world. There is an urgent need to look into the measures to control water pollution although a lot many efforts and schemes have already been announced by the Government in this regard. To make the students aware of this we have prepared short and long essays for students which shall inform them about water pollution and the means to minimise it.

4 0

3 years ago

Each of the four pedigrees that follow represents a human family within which a genetic disease is segregating. Affected individ

Ne4ueva [31]

Answer:

The following four traits are -:

Pedigree 1 - A recessive trait (autosomal recessive) is expressed by pedigree 1.
Pedigree 2- Recessive inheritance is defined by Pedigree 2.
Pedigree 3 - The inheritance of the dominant trait (autosomal dominant) is illustrated by Pedigree 3.
Pedigree 4- An X-like dominant trait is expressed by Pedigree 4.

Explanation:

Explaination of each pedigree chart-

Pedigree 1 demonstrates the recessive trait since their children have been affected by two unaffected individuals. If the characteristics were X-linked, in order to have an affected daughter, I-1 would have to be affected. $X^A$ In this, both parents are autosomal recessive trait carriers, so the child will be affected by a 1/4 (aa)
Recessive inheritance is defined by Pedigree 2. This is X-related inheritance as autosomal recessive inheritance has already been accounted for in part 1. This inference is confirmed by evidence showing that the father (I-1) is unaffected and that only the sons exhibit the characteristic in generation II, suggesting that the mother must be the carrier. The individual I-2 is a carrier for this X-linked trait. A typical Xa chromosome is attached to the unaffected father (I-1), so the chance of carrier II-5 is 1/2. Probability of an affected son = 1/2 (probability II-5 is a carrier) x 1/2 (probability II -5 contributes ( $X^A$ ) x 1/2 (probability of Y from father II-6) = 1/8. An affected daughter's likelihood is 0 because a typical $X^A$ must be contributed by II-6.
The inheritance of the dominant trait is demonstrated by Pedigree 3 because affected children still have affected parents (remember that all four diseases are rare). The trait must be autosomal dominant because it is passed down to the son by the affected father. There is a 1/2 risk that the heterozygous mother (II-5) would pass on mutant alleles to a child of either sex for an autosomal dominant feature.
Pedigree 4 is an X-linked dominant function characterized by the transmission to all of his daughters from the affected father but none of his son. On the mutant X chromosome, the father (I-1) passes on to all his daughters and none of his sons. As seen by his normal phenotype, II-6 therefore does not bear the mutation. An affected child's likelihood is 0.

In the question the pedigree chart was missing ,hence it is given below.

7 0

3 years ago

Select the correct answer from each drop-down menu. Alma is walking in a park. Suddenly, a wild dog charges toward her. Alma is

zaharov [31]

Answer:

when she sees the dog charging towards her her eyes sees it and sends message to the brain and then brain gives the response to run away but after running sometimes she realises that she has left the dog far so her brain responds to slow down so, after a while her heart beats also slow down.

hope it helps..

4 0

3 years ago