The correct answer is option B. Devonian.
The amphibians are the tetrapods (having four limbs), which can live in both water and land, but for reproduction purpose, they need water and early life is exclusively aquatic. The amphibians are known to be evolved from lobbed finned fishes around 370 million years ago in the Devonian period of the Paleozoic Era.
Answer:
The resistance allele is recessive
Explanation:
According to Darwin's pea experiment, the recessive trait appeared after a few generations.
Here in this case too the resistant individuals appeared after the first generation. This also implies that the offspring of first generation must be carrier of this recessive trait.
Let the susceptible domesticated strain trait be represented by "S"
and the recessive resistant wild strain trait be represented by "s"
Then,
F1 generation
SS * ss
Ss, Ss, Ss, Ss ------ All are heterozygous susceptible individuals
F2 generation
Ss * Ss
SS, Ss, Ss, ss
ss shows reappearance of resistant wild trait.
Hence, the resistance allele is recessive.
Answer:
22 cells
Explanation:
The concentration of numbers of cells = 6.74 x 10⁶ cells/ml
Dilution stages includes = 1:100 ; 1:100 & 1:3
The consecutive dilution stages can be calculated as:
= (6.74 x 10⁶) × (1/100)(1/100)(1/3)
= 222.42 cells/ml
= 2.22 × 10² cells/ml
So after addition 0.1 ml of the final dilution to a spread plate, the number of CFUs ( Colony forming units) we expect to count will be:
= (2.22 × 10² cells/ml)(0.1 ml)
= 22.2 cells
≅ 22 cells.
The question is incomplete. The complete question is as follows:
Which characteristics of DNA polymerase I raised doubts that its in vivo function is the synthesis of DNA leading to complete replication?
its composition of a single polypeptide chain.
deficiency of enzyme in some organisms that are still capable of DNA synthesis.
requirement of Mg2+ presence in order for the enzyme to work.
low stability under normal physiological conditions.
Answer:
Deficiency of enzyme in some organisms that are still capable of DNA synthesis
Explanation:
The DNA polymerase I may be defined as the important enzyme that play an important role in the DNA replication of prokaryotes. DNA pol I is the replicating enzyme, DNA repair enzyme and can also acts as the exonuclease.
DNA pol I has been studied invitro and Arthur Korenberg explain the discovery of the DNA pol I. This DNA pol I plays an important role in DNA repair rather than the replication process. This explained invivo by the fact that some in some organisms the deficiency of this enzyme do not halt the process of replication. If the DNA pol I acts as the main replaicating enzyme, the DNA synthesis must be stopped in the organisms that lack DNA synthesis.
Thus, the correct answer is option (2).
petroleum
fuel cells
wind energy
oil
nuclear energy
tidal energy
Answer:
The correct answers are "coal", "petroleum", "fuel cells" and "oil".
Explanation:
The energy solutions that release pollution into the air are coal, petroleum, fuel cells and oil. Coal was one of the first sources of energy to be used in the industry, the smoke generated from coal power plants is extremely dangerous and pollutant. Petroleum and its by products are very contaminant as well, producing high amount of carbon dioxide emissions as well as other greenhouse gases. Fuel cells are much cleaner than the other energy solutions however they still produce contamination into the air, specifically one ounce of pollutant for every 1,000 kW·h produced. Oil is also a contaminant of air, particularly when oil spills take place which are producers of carcinogens and aerosols.
Answer: this is because with triplet sequences, diversities would be generated and the possibility of overlapping is minimal
Explanation:
Answer:
Geneticists believe, even before direct experimental evidence was obtained, that the genetic code would turn out to be composed of triplet sequences and be non overlapping because a triplet code gives 64 possible combinations but we only have 20 essential amino acids in our human proteins so there's room for some redundancy. That way some point mutations will still be able to correctly code for the desired protein.
Explanation:
The Genetic Code would turn out to be composed of triplet sequences means that the -
Genetic Code is stored on one of the two strands of a DNA molecules as a linear, non-overlapping sequence of the nitrogenous bases Adenine (A), Guanine (G), Cytosine (C) and Thymine (T). These are the of "letters of the alphabet," that are used to write the "code words."
The genetic code consists of a sequence of three letter "words," (sometimes called 'triplets', sometimes called 'codons'), written one after another along the length of the DNA strand.
Each code word is a unique combination of three letters (like the ones shown below in the attachment) that will eventually be interpreted as a single amino acid in a polypeptide chain. There are 64 code words possible from an 'alphabet' of four letters.
One of these code words, the 'start signal' begins all the sequences that code for amino acid chains. Three of these code words act as 'stop signals' that indicate that the message is over. All the other sequences code for specific amino acids.
However, some amino acids are only coded for by a single 'word,' while some others are coded for by up to four 'words.' The genetic code is redundant.
Genetic codes do not overlap: The genetic code is composed of nucleotide triplets. In other words, three nucleotides in mRNA (a codon) specify one amino acid in a protein. The code is non-overlapping. This means that successive triplets are read in order.
Answer:
b. Trans fats are worse for heart health than saturated fats because they raise LDL cholesterol and lower HDL cholesterol.
c. Increasing intake of plant foods may be one of the easiest ways to decrease LDL cholesterol.
d. Typically, the higher your consumption of saturated fats, the higher the LDL cholesterol levels in your blood.
Explanation:
Generally, the consumption of saturated fat increases the amount of LDL cholesterol in the blood system while the consumption of unsaturated fat can reduce the amount of LDL cholesterol in the blood system. In addition, the consumption of plant food can reduce the amount of LDL in the blood system. Trans fats are more harmful to one's heart than saturated fat because they can increase the amount of cholesterol in the blood system.
Answer:b,c,d
Explanation:a. Unsaturated fats are mostly beneficial to health, e.g- omega 3 fatty acids, and are not known causes of LDL increase.
b. Trans fats are known to increase LDL cholesterol while also decreasing HDL cholesterol levels. We do not find this in saturated fats which are known to only increase LDL cholesterol.
c. Plants possess "soluble fiber" that drastically help to reduce cholesterol levels. They are known to be very low in saturated fats, and also free of cholesterol.
d. Saturated fats are common causes of elevated LDL in blood stream.
e. Dietary cholesterol as opposed to serum cholesterol are fats found in our diets(food) that may contain high levels of cholesterol that increase LDL levels in blood.