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Hi,
Harshey and Chase did a great experimentation which was basically a two step experiment to prove that DNA and not proteins are the actual carriers of genetic information from parents to offspring.
- In the first part of their experiment, they used bacteriophages (virus that eat bacteria). They used radioactively labeled sulphur(35S) medium to grow bacteriophages and observed that all the bacteriophages had proteins with radioactive sulphur(35S).
- In the next step they allowed these phages to infect bacteria and to their surprise, they found that the bacteria did not had radioactively labeled sulphur in them because the coat of bacteriophage stays outside the body of bacteria when it attacks it. This proved that DNA not proteins were the hereditary material.
- To make their results more reliable, they did a second experimentation in which, they marked the DNA of the phage with radioactive phosphorus 32P. After labeling DNA, they repeated the same experiment and this time, they found radioactive phosphorus inside the bacteria.
<em>This meant that the bacteria had DNA of phage entered inside them and this again proved that DNA not proteins are the hereditary material. You can see attached image for better understanding.
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Hope it help!
Answer:
The correct answer will be options A, B and E.
Explanation:
Red blood cells or RBC or erythrocytes are the cells present in the connective tissue which forms the blood. RBC perform various functions in the body but the primary function is the transport of the gases in the body.
The RBC are continuously formed in the bone marrow region of the bone form the hemopoietic stem cell found in the bone marrow. These cells produce a large amount of RBC that is about 2 million cells per second in a healthy adult.
When RBC are formed posses nucleus but when mature, they lack nucleus that is genetic material and organelles like mitochondria so, they are not able to divide.
These RBC contain haemoglobin in their cytoplasm which shows high affinity to bind oxygen and low affinity to bind carbon dioxide to the iron group of haemoglobin.
Thus, options A, B and E are the correct answer.
Answer:
The parents must be Tt, Tt
Explanation:
Based on these results, we can conclude that each of the parents will have one dominant (T) and one recessive allele (t). We can prove this by drawing the Punnett square:
T t
T TT Tt
t Tt tt
We can see that the offspring will have the Tt genotype in two cases, the TT genotype in one case, and the tt genotype in one case, as well. Now we need to do some basic math. Two out of four is 50% (Tt - 50%), and one out of four is 25% (TT - 25%, tt - 25%).
This means that the parents must be Tt, Tt.