1. Scientific method is the techniques that scientists used to carry out investigation process. It is made up of five steps, which are:
a. Observation: this is the stage in which a scientist make an observation to which he did not have an explanation.
b. Formation of a research question: in accordance to observation made, the scientist form a question on which his experiment will be based
c. Formation of hypothesis: at this stage the scientist offers a proposed explanation for the observation which he had made and state what he expects at the end of the experiment.
d. Conduction of the experiment: at this stage the scientist carry out the experiment using appropriate means.
e. Analysis of data and drawing of conclusion: this is last stage of the investigation, at this stage, the scientist analysis the results he obtained and draw a conclusion based on the results of the data.
2. Scientists used scientific method to carry out scientific investigations because the method minimize the influence of bias and prejudice in the experiments that they carry out. The method provides an objective, standardized approach to scientific investigation; this result in reproducible results which can be achieved by other scientists in every parts of the world. The method also helps to minimize errors during investigation.
The complementary sequence of nucleotides found on the other strand of DNA is <u>ACGAAT</u> when one strand in a segment of a gene has the base sequence TGCTTA.
<u>Explanation:</u>
Deoxyribonucleic acid is the one which carries the genetic information from the parent to the offspring. During DNA replication one strand of DNA replicates to produce another strand.
The DNA molecule have a anti-parallel structure and the two strands run in opposite direction. If in one strand in a segment of a gene has the base sequence TGCTTA the complementary sequence of nucleotides found on the other strand of DNA will be ACGAAT.
Answer:
The answer is D.
Explanation:
Autotrophs are known as producers which gets energy from sunlight and produces their own food.
The DNA polymerases are enzymes that create DNA molecules by assembling nucleotides, the building blocks of DNA. These enzymes are essential to DNA replication and usually work in pairs to create two identical DNA strands from one original DNA molecule. During this process, DNA polymerase “reads” the existing DNA strands to create two new strands that match the existing ones.
Every time a cell divides, DNA polymerase is required to help duplicate the cell’s DNA, so that a copy of the original DNA molecule can be passed to each of the daughter cells. In this way, genetic information is transmitted from generation to generation.
Before replication can take place, an enzyme called helicase unwinds the DNA molecule from its tightly woven form. This opens up or “unzips” the double stranded DNA to give two single strands of DNA that can be used as templates for replication.
DNA polymerase adds new free nucleotides to the 3’ end of the newly-forming strand, elongating it in a 5’ to 3’ direction. However, DNA polymerase cannot begin the formation of this new chain on its own and can only add nucleotides to a pre-existing 3'-OH group. A primer is therefore needed, at which nucleotides can be added. Primers are usually composed of RNA and DNA bases and the first two bases are always RNA. These primers are made by another enzyme called primase.
Although the function of DNA polymerase is highly accurate, a mistake is made for about one in every billion base pairs copied. The DNA is therefore “proofread” by DNA polymerase after it has been copied so that misplaced base pairs can be corrected. This preserves the integrity of the original DNA strand that is passed onto the daughter cells.

A surface representation of human DNA polymerase β (Pol β), a central enzyme in the base excision repair (BER) pathway. Image Credit: niehs.nih.gov
Structure of DNA polymerase
The structure of DNA polymerase is highly conserved, meaning their catalytic subunits vary very little from one species to another, irrespective of how their domains are structured. This highly conserved structure usually indicates that the cellular functions they perform are crucial and irreplaceable and therefore require rigid maintenance to ensure their evolutionary advantage.
Answer:
The Arctic tern is a medium-sized bird around 33–36 cm (13–14 in) from the tip of its beak to the tip of its tail. The wingspan is 76–85 cm (30–33 in). The weight is 86–127 g (3.0–4.5 oz.).
Explanation:
