A biochemist isolates and purifies various molecules needed for DNA replication. When she adds some DNA, replication occurs, but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mixture? A biochemist isolates and purifies various molecules needed for DNA replication. When she adds some DNA, replication occurs, but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mixture? Okazaki fragments nucleotides DNA ligase primase DNA polymerase

DNA ligase

Explanation: During replication, two new strands are synthesized: The leading strand and the lagging strand.

The leading strand is synthesized in a continuous manner while the lagging strand is synthesized discontinuously in short segments called the Okazaki fragments. The leading strand is the strand whose 5'->3' synthesis is in the direction of the fork movement while the lagging strand is the strand whose 5'->3' synthesis is in the direction opposite to the fork movement. The Okazaki fragments are joined by an enzyme known as DNA ligase. DNA ligase is one of the enzymes involved in DNA replication which catalyzes the joining of two or more polynucleotide chains.

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?

answer: the correct option is d. enzyme

lactase and carbonic anhydrase are the examples of enzymes.

lactase is an enzyme, which is present in the small intestine of mammals. it in the digestion of the disaccharide, lactose ( milk sugar) by converting it into two monosachharide, which are glucose and galactose.

carbonic anhydrase is present in the red blood cells. this enzyme plays significant role in the transport of co₂. it in the conversion of co₂ and h₂o into carbonic acid, which is then dissociated into bicarbonate ions and hydrogen ions.