Answer:
The correct answer is B
Explanation:
Transposons need to regulate their copy number to avoid errors with chromosomal pairing during meiosis and mitosis such as unequal crossover.
A typical example of this error is called the Alu Sequence or Elements. Alu elements contain more than one million copies found everywhere in the genome of human beings.
Many inherited human diseases such as cancer are related to Alu insertions.
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Answer
Ventricular systole begins during the <u>isovolumetric contraction </u>phase of the cardiac cycle.
Explanation
1. Ventricular ejection
The forceful expulsion of blood from the ventricles into the aorta and the pulmonary arteries.
2. Isovolumetric contraction
The interval between the closing of the AV valves and the opening of the semilunar valves (aortic and pulmonary valves) is known as isovolumetric contraction. it is the beginig of systole. it is the first chamber systolic event. The myocardial muscle fibers have begun to shorten but have not developed enough pressure in the ventricles to overcome the aortic and pulmonary end-diastolic pressures and open the aortic and pulmonary valves. During this period of muscle fiber contraction, the ventricular volumes do not change.
3. Ventricular filling
In this stage AV valve is opened and the blood that has accumulated in atria flow rapidly into ventricles. The ventricular volume increase rapidly. A third heart sound known as S3 is heared during this stage.
4. Isovolumetric relaxation
It is the beginning of diastole. The AV valve are closed at beginig. The atrium in diastole has been filling with blood on top of the closed AV valve, causing atrial pressure to rise gradually. The pressure in the ventricles continues to drop. Ventricular volume is at a minimum and is ready to be filled again with blood.
Answer:
Error: The Methionine at the end of the chain
Explanation:
Hello! Let's solve this!
The start codon is AUG, this codon encodes Methionine. Therefore all proteins will start the amino acid sequence with Methionine.
In this case, the student placed the Methionine at the end of the chain, so that is the mistake. Methionine goes to the beginning of the chain.
Answer:
1.2 mL
Explanation:
<em>This is a problem of simple dilution. The dilution principle simply agrees that the number of moles before dilution must be equal to the number of moles after dilution.</em>
Recall that: number of moles = mass/molar mass or molarity x volume.
Hence, for the dilution principle:
initial molarity x initial volume = final molarity x final volume.
In this case, initial molarity of NaOH = 1 M, initial volume = ?, final molarity = 0.1 M, final volume = 12.0 mL.
Initial volume = final molarity x final volume/initial molarity
= 0.1 x 12/1 = 1.2 mL
It thus means that 1.2 mL of 1 M NaOH would be taken and then diluted up to 12.0 mL mark by the addition of distilled water in order to produce 12.0 mL, 0.10 M NaOH solution.
Answer: Annelida
Leeches are soft bodied segmented parasitic worms. They belong to the phylum Annelida. They are hermaphrodites which means they exhibit sex organs of both male and female.
The characteristics which are found in leeches which group them into Annelida are:
1. The body of the leeches are bilaterally symmetrical like other Annelids. The body organs are also segmented.
2. They have a closed circulatory system in which the heart pumps the blood to all the parts of the body.
3. Leeches either exhibit a protusible pharynx or proboscis which allows them to suck the blood of the host such features are also common in other Annelids.
