Freshman biology problem, super urgent!! Call for help

Choose A, because there are two ways to consume the energy ingested by sheep, one is to become the manure of sheep to be used by the decomposer, and the other is the energy of sheep assimilation, so n-36%n is the energy of sheep assimilation.

Among them, there are two ways to consume the energy of sheep assimilation, one is that it can be consumed as respiration, and the other is that it can be used for growth, development and reproduction. The energy used for growth, development and reproduction can be divided into: 1.

Posthumous remains (can be decomposed by the decomposer), II. Secondary consumer intake. Since the question does not tell the energy used by the decomposer after the death of the sheep, B is not selected.

In the same way, because the question does not tell the energy used by the decomposer after the death of the sheep, it is not chosen.

AD analysis: A assimilation amount = intake - the content of organic matter in the feces, so it is easy to know that A is right;

b energy stored in sheep = assimilation - respiration consumption, so it should be 16%n;

c. The energy flowing to the decomposer, i.e., the energy in the feces, is 36%n;

D flows to the next level of energy, i.e. the energy stored by the sheep, which is the same as option B, so D is paired.

The energy ingested into the body is n, and after digestion, 36%n is taken away with feces, but in fact, the assimilated energy is 64%n. The flow to the trophic level should be 64%n of the assimilation of the sheep minus 48%n of the energy lost by respiration, that is, 16%n (10-20)%. Because it is impossible to use all of them to the next trophic level.

Hope that is clear.

The energy ingested by sheep is n, which is the total amount.

Among them, the energy in sheep manure is 36%n, and the energy lost by respiration is 48%n, so the energy flowing from sheep to the next trophic level is n—(36%n + 48%n)==16%n

The key to choosing A is to figure out the relationship between various energies, and any energy will not disappear for no reason, but will only be transformed.

Respiratory energy loss 48%n

Assimilated Energy 64% n{ Decomposer Dismantled Energy.

Energy ingested n{ energy present in sheep 16% n{ energy in feces 36% n flows to the next trophic level of energy.

This is my own summary, I hope it will be useful to you.

First trophic level intake - excretion = first trophic level assimilation (assimilation efficiency = assimilation intake).

First trophic level assimilation - self-respiration consumption = first trophic level production (production efficiency = production assimilation).

First trophic level production – decomposer consumption – unutilized = second trophic level intakenext

That is, the energy lost during the two assimilation processes is: first-level respiration consumption, first-level decomposition consumption, first-level unutilized, and second-level excretion.

Choose A, D

The energy in sheep manure was 36%n, and the assimilation energy of sheep was n-36%n=64%n

Assimilation of 64%N, the energy lost by respiration is 48%N, that is, the survival of the sheep consumes 48%N, and the remaining energy accumulates in the sheep, and the accumulated energy will flow to the next trophic level 64%N-48%N=16%N

The answer is D.

I don't know if I'm doing it right, so let's just say it.

C21HxoYN4S2 has 4 N and 2 S, so it can be inferred that it is composed of four amino acids and contains 2 cysteines (C3H7O2NS). then a is wrong.

2 cysteines (C3H7O2NS) have 6 Cs, and the remaining 15 C2 amino acids can only be phenylalanine and leucine.

The four amino acids were calculated as having a total of C21H38O8N4S2, and 3 molecules of H2O and 2 H+ were removed, and the final polypeptide was wrong.

The polypeptide is composed of 3 amino acids, c wrong.

3H2O and 2H+ are removed during peptide formation, and the molecular weight is 56 in total. Pick D

If so, I'll tell you how I did it, or ignore me.

Choose D! It's too much trouble to explain. Think for yourself!

If there is nothing wrong with this to the Tao itself, some knowledge from the university should be used.

The accumulation of genes is used.

Additive effect: when two pairs of alleles control a trait at the same time, one trait is expressed when both pairs of genes are dominant, another trait is expressed when only one pair of genes is dominant, and a third trait is expressed when both pairs of genes are recessive. The proportion of phenotypes in AABB inbred offspring is 9:

6:1, the phenotypic ratio of the tested offspring is 1:2:

1。<> use the dominant superposition of the gene (try it yourself).

Dominant superposition of genes: when two pairs of alleles control a trait at the same time, the dominant state of one pair of genes has a masking effect on the other pair of genes (regardless of dominant recessiveness), that is, when a pair of genes is dominant, another trait is manifested when the other pair of genes is dominant and the first pair of genes is recessive, and a third trait is expressed when both pairs of genes are recessive. The phenotypic proportion of ABB inbred offspring is 12:

3:1, and the phenotypic ratio of the offspring is 2:1

1。Use the additive effect of genes (try it yourself).

Additive effect: The effect of both genes is the same, but the more dominant genes accumulate, the more obvious the trait manifests. There are 5 phenotypes in ABB inbred offspring (4 dominant genes, 3 dominant genes, 2 dominant genes, 1 dominant gene, and 0 dominant genes), and the ratio is 1:

1. The phenotypic ratio of the offspring is 1:2:1.

I feel that there is something wrong with this body itself

Because the labeled phage DNA has two strands, after the phage is impregnated with bacteria, the phage uses its own DNA as a template, uses the raw materials in the bacteria, etc., synthesizes its own DNA, and guides the synthesis of its own protein, assembles into a new progeny phage, and finally lyses the bacterium to release the newly synthesized phage.

The replication of DNA follows the principle of semi-reserved replication, the two DNA strands of the parent are tagged and replicated after distending, and the DNA of two progeny phages of all the daughter DNA of the synthesized phage is tagged because it contains the parent strand, and the DNA of the rest of the phages is not tagged, so the answer is 2 n

The double-stranded DNA is labeled and infects the bacteria, and each single-stranded DNA is paired with the synthesized new DNA, and finally 2 of the n phages are tagged, so B is chosen

Guanine: g is paired with c so g = c g + c = 80 + 80 = 160

a+t=240-160=80 because a t is paired, so a=t=80 2=40

Uracil: U is paired with A so A=U=40

Because guanine = cytosine, because there are 80 guanine, there are 80 cytosine, so there are 80 deoxynucleotides left, and because in DNA adenine = thymine, so adenine and thymine are left 80 and transcription into messenger RNA, adenine = uracil, so the answer is A, that's it! If you still don't understand, you can also consult me!