The tetrad occurs during the first phase of meiosis. It is the foursome of chromatids that forms when replicated homologous chromosomes align. It must be formed for crossing over to occur. It is broken apart when the homologous chromosomes separate in meiosis I
Answer:
Nothing
Explanation:
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Yes. <span>But if you look closely, they are still not exactly the same. They will always have some physical differences due to differences in their environment. Some </span>identical twins can<span> have </span>different heights<span> and weights. This is because </span>height<span> and weight are controlled by what you eat as well your DNA.</span>
Answer:
C. 3, 2, 1
Explanation:
During a single PCR cycle, the very first step is the heat separation of the double stranded DNA. Primer binds only single stranded DNA/RNA because it has complimentary bases which match single strand of DNA/RNA that is why it is necessary to unwind both the strands of DNA by providing temperature.
As soon as the DNA strands have separated by increasing the temperature to ~ 95 °C, in the next step the primer binds the portion of DNA which is complimentary to the bases of the primer. In order for primer to bind DNA, the temperature is lowered to ~ 72 °C and the process is called as annealing.
Once primer has bound to the DNA, the next step is polymerization i.e. nucleotides which are the monomer units of DNA are added one by one with the help of enzyme named as Taq polymerase. This is how the strand extends ahead of primer and exact copies of the given DNA are produced.
Note: PCR may be considered as in vitro DNA synthesis or replication.
