Movement of mouth and lips
Answer:
The leading strand is copied in the 5' to 3' direction and the lagging strand is copied in the 3 to 5 direction.
Explanation:
1. The original DNA molecule remains intact, although it acts as a template for the formation of a copy that contains two new antiparallel strands. - this is false.
DNA replication is said to be "semi conservative". This is because in making a new DNA molecule, one of the strands is from the original DNA molecule and one is new. This is true for each new molecule produced One DNA molecule makes 2 new molecules, each containing one of the original strands
2. The leading strand is copied in the 5' to 3' direction and the lagging strand is copied in the 3 to 5 direction. This is true. The synthesis of each strand occurs through a distinct mechanism. The leading strand is synthesised 5'-3' (towards the replication fork), and the lagging strand is synthesised from 3'-5', away from the replication fork. T
he leading strand is synthesised continuously using an RNA primer to begin the process. The lagging strand is synthesised discontinuously, with several short primer sequences permitting the synthesis of short fragments (Okazaki fragments) that are later joined by DNA ligase. <em>NB: this is easy to remember if you consider that </em><em>3 lags behind 5</em>
3. Both strands are copied to form Okazaki fragments, which are later annealed by DNA Ligase. This is false. Only the lagging strand replicates to form Okazaki fragments
4. The replication process proceeds on both strands in the same direction, which requires that RNA primers bind to the lagging strand. This is false. The strands are synthesised in different directions
Answer:
d. 3:1
Explanation:
A purebred organism is an organism that contains identical alleles for a particular gene e.g rr or RR. According to this question, in a cross between a purebred dominant organism e.g RR and a purebred recessive organism e.g rr, each parent will produce R and r gametes respectively.
Using the gametes in a punnet square (see attached image), a heterozygous organism (Rr) will be produced in the F1 generation. If these heterozygous organism is self-crossed i.e. Rr × Rr, the following F2 offsprings will result;
RR, Rr, Rr, and rr.
RR, Rr and Rr will exhibit dominant traits while rr will exhibit recessive traits. This means that the F2 generation contains a ratio of approximately 3:1 expressed dominant traits to recessive traits.
