Describe the key steps in the semiconservative replication of dna.

Semi-conservative replication is meant for the description of DNA replication and it i s called so because parent DNA helix produces two copies of original DNA, one of which consist of original DNA.

The three main steps in DNA replication includes Initiation, Elongation and Termination.

In the initiation phase, replication begins at origin of replication where helicase enzyme breaks the hydrogen bonds between base pairs and tends to unwind the double helix where the topoisomerase stabilizes the newly formed single strand DNA. DNA polymerase allows elongation to occur in leading direction and catalyses the addition of new nucleotide to new single strands. short sequences of RNA called primers paired to template strands with the help of primase. replication of both strands occurs at the same time one in continuous (3'-5') and other in discontinuous (5'-3') direction, which are called leading strands. new nucleotides added in 3' end and moving to replication fork while discontinuous synthesis occur on parent strand (5'-3') called lagging strand and completed in segments called okazaki fragments. Then primase add primers ahead at 5' end of the lagging strand. DNA  polymerase ||| adds short sequences of nucleotides to the primer. During termination, exonuclease replaces DNA primer and DNA nucleotide and DNA ligase helps in making bonding between fragments and replaced nucleotide. Another exonuclease helps in proofreading the newly formed DNA and corrects the errors in sequences. At the end of the parent strands, telomeres are present which keeps on catalyzing by telomerase and completes, the formation of copies of parent DNA.

your body is trying to warm itself up. or more precisely, sensors in your skin send messages to your brain to generate heat to your body.

an individual’s sex (i.e., whether they are a male or female) is determined by the sex chromosomes. most people have two sex chromosomes, one that is inherited from their mother and one that is inherited from their father. typically, females have two x chromosomes (xx) and males have one x chromosome and one y chromosome (xy). conditions caused by changes (“mutations”) in genes located on the x chromosome are considered x-linked.

x-linked recessive inheritance

most x-linked conditions are recessive. this means that in a person with two x chromosomes (most females), both copies of a gene (i.e., one on each x chromosome) must have a change or mutation whereas in a person with one x chromosome (most males), only one copy of a gene must have a mutation. a female with a mutation in one copy of a gene on the x chromosome is said to be a “carrier” for an x-linked condition. a male with a mutation in a gene on the x chromosome is typically affected with the condition. because females have two copies of the x chromosome and males have only one x chromosome, x-linked recessive diseases are more common among males than females. however, x-linked recessive diseases can occur in both males and females.

for x-linked recessive disorders, an unaffected carrier mother who has a mutation in a gene on the x chromosome can transmit either the x chromosome with this mutation or a “normal” x chromosome to her children. if the father is unaffected, none of her daughters will be affected and all of her daughters will be unaffected—since they will inherit at least one normal x chromosome from their father. however, each daughter will have a 50% chance of being an unaffected carrier like her mother and a 50% chance of both x chromosomes being normal.