Question: Which two statements are true for the leading strand in DNA?
It is synthesized toward the replication fork.
It is synthesized in the 3′ to 5′ direction.
It is synthesized away from the replication fork.
It is synthesized in the 5′ to 3′ direction.
Answer:
The two statements that are true for the leading strand in DNA are "it is synthesized toward the replication fork and it is synthesized in the 5′ to 3′ direction"
Explanation:
Leading strand in DNA is the strand of new DNA being synthesized in the same direction where the replication fork is moving. The movement of replication fork allows the access of template for the new DNA. The DNA synthesis is continuous in the leading strand. It is synthesized in the 5' to 3' as DNA synthesis always takes place in this direction. This is because dNTP ( deoxyribonucleoside triphosphate) provides free 3' OH group where new dNTP can be added by the enzyme DNA polymerase.
Answer:
Letter C
Explanation:
Salmon have a physiological adaptation that allows osmoregulation to occur in two different environments (seawater and freshwater). There are specific molecules in the salmon gills that "pump" and "remove" Na and Cl ions. When at sea these molecules pump the ions out of the salmon's body and into freshwater, the same molecules remove Na and Cl from the water bringing it into the animal's blood.
Answer:
The correct answer is B. Worms move through changes in body structure caused by contraction of muscles compressing their watery fluid.
Explanation:
The hydroskeleton consists of a fluid-filled cavity, surrounded by muscles. The fluid pressure and the action of the muscles that border it, serve to change the body's shape and produce a movement such as digging or swimming. The successive contraction of various metamers, which are provided with bundles of circular and longitudinal muscle fibers, stretching and thickening parts of the body, allow it to move horizontally. Hydrostatic skeletons have a role in the locomotion of annelids, nematodes and other invertebrates. The hydroskeleton has similarities with the hydrostatic muscles.
<span>Protozoa
Viruses
Algae
Fungi
Bacteria</span>
Answer:
At the bottom of the sequence
Explanation:
According to the "principle of superposition of strata", the oldest rocks are formed at the bottom of sedimentary rock sequences.
The oldest rock layer would contain the the oldest fossil. Weathering, erosion, transportation and deposition would bring all sediments which includes rock materials and remains of living organisms to the basin where they would be lithified to form sedimentary rocks. This makes the oldest fossil to be at the bottom of the sequence. As time progresses, the fossil sequence would continue to accumulate and young upwards as the strata becomes relatively younger. Also, we know that fossils succeed one another in a definite manner.
This why relative dating of rocks can be possible.
