Answer:
In explanation.
Explanation:
What is a punnett square used for?
It is a way to store data and keep track of things. It helps to predict the variations and probabilities that can come from cross breeding.
What do the probabilities of the possible offspring all add up to?
All can have 100%, 75%, 50%, or 25% depending on the specific trait.
No but they are considered protected
Answer:
The correct answer is b. He determined that DNA contains four nitrogenous bases.
Explanation:
Levene was an American biochemist who studied the structure of DNA in the early 1900s and in 1920 he found that DNA consists of four nitrogenous bases that are Adenine, Guanine, Thymine, Cytosine.
He also found deoxyribose sugar and phosphate group and said that nucleotide is the basic unit of DNA which contains a ribose sugar with attached nitrogenous base and phosphate group.
He also concludes that an equal amount of adenine, guanine, thymine, and cytosine makes the DNA which is now known as tetranucleotide hypothesis. So the correct answer is b. He determined that DNA contains four nitrogenous bases.
