Biology 1 Mid-term Practice Exam

The chemical formula for water is H2O, which means that it consists of two hydrogen atoms bonded to one oxygen atom. This formula represents the correct ratio of atoms in a water molecule.

Proteins are made up of amino acids. Amino acids are the building blocks of proteins and are linked together through peptide bonds to form long chains. These chains then fold and interact with each other to create the three-dimensional structure of a protein. Each amino acid has a specific side chain that determines its chemical properties and function within the protein. Therefore, the correct answer is amino acids.

Biology is the correct answer because it is the scientific study of life and living organisms. It involves examining the structure, function, growth, origin, evolution, and distribution of living organisms. Biology encompasses various sub-disciplines such as botany, zoology, genetics, microbiology, and ecology, allowing scientists to explore and understand the complexities of life on Earth.

Chloroplast is the correct answer because it is a unique organelle found only in plant cells. It is responsible for photosynthesis, the process by which plants convert sunlight into energy. Chloroplasts contain chlorophyll, a pigment that gives plants their green color and is essential for capturing light energy. These organelles are not present in animal cells, making chloroplasts a distinguishing feature of plant cells.

Active transport always requires energy because it is the movement of molecules or ions against their concentration gradient, from an area of lower concentration to an area of higher concentration. This process requires the use of energy in the form of ATP (adenosine triphosphate) to pump the molecules or ions across the cell membrane. In contrast, passive transport, osmosis, and diffusion do not require energy as they involve the movement of molecules or ions along their concentration gradient, from an area of higher concentration to an area of lower concentration.

Baking soda, or sodium bicarbonate, has a pH of 9. This means that it is slightly alkaline. When mixed with an acid, such as vinegar, it produces carbon dioxide gas, causing it to bubble and expand. Baking soda is commonly used as a leavening agent in baking, as well as for cleaning and deodorizing purposes. Its alkaline nature also makes it an effective remedy for heartburn and indigestion.

The statement "All living things are made of one or more cells" is part of the old cell theory. The cell theory, formulated in the 19th century, states that all living organisms are composed of cells, cells are the basic units of structure and function in living organisms, and that all cells come from pre-existing cells. This statement aligns with the first principle of the cell theory, which emphasizes that all living things are composed of cells. Therefore, the answer is true.

The statement "A mutation is always bad" is incorrect. Mutations are changes in the DNA sequence that can occur naturally or be induced by various factors. While some mutations can be harmful and lead to genetic disorders or diseases, not all mutations are detrimental. In fact, mutations are the driving force of evolution as they introduce genetic variation into populations. Beneficial mutations can provide organisms with advantages such as increased resistance to diseases or improved adaptation to their environment. Therefore, it is incorrect to categorize all mutations as bad.

Carbohydrates provide organisms with quick energy because they are broken down quickly and easily into glucose, which can be readily used by cells for immediate energy needs. This is in contrast to fats and proteins, which take longer to break down and provide energy on a longer-term basis.

Eugenics is considered a pseudo science because it involves the study of or belief in improving the genetic quality of the human population through selective breeding and sterilization. It was popular in the early 20th century, particularly in Nazi Germany, where it was used to justify the Holocaust and forced sterilizations. However, eugenics has been discredited and widely criticized for its unethical and discriminatory practices. Therefore, the statement that Eugenics is a pseudo science is true.

The nucleotide sequence of every person (except twins) is different. This is because the nucleotide sequence is determined by the genetic information encoded in each individual's DNA. DNA contains a unique combination of nucleotides, which are the building blocks of DNA. These nucleotides can be arranged in countless different ways, resulting in unique nucleotide sequences for each person. Twins, on the other hand, may share a very similar nucleotide sequence due to their identical genetic makeup.

This statement is true because the scientific method typically involves two main steps: stating the problem or question that needs to be answered, and then formulating a hypothesis or possible explanation for the problem. These steps are essential in the process of conducting scientific research and experimentation to find solutions or answers to various problems or questions.

The correct answer is "Semipermiable". A semipermeable membrane allows certain substances to pass through while restricting the passage of others. It selectively permits the movement of specific molecules or ions based on their size, charge, or solubility. This characteristic is essential for various biological processes, such as osmosis and filtration, where the membrane acts as a barrier to control the flow of substances.

Thymine is not present in RNA. RNA contains a different nitrogenous base called uracil, which pairs with adenine. Thymine is only found in DNA, where it pairs with adenine.

All of the above options are characteristics of DNA. DNA is double stranded, meaning it consists of two strands that are complementary to each other. It contains thymine, which is one of the four nitrogenous bases found in DNA. It also contains cytosine, another nitrogenous base. Therefore, all of these options are correct characteristics of DNA.

The given question asks for a characteristic that is NOT associated with a living thing. The options provided are "Made up of Cells," "Organized," "Grows and Develops," and "None of the above." The correct answer is "None of the above" because all the other options are indeed characteristics of living things. Living things are made up of cells, exhibit organization in their structure and function, and undergo growth and development throughout their lifespan. Therefore, "None of the above" is the only option that does not represent a characteristic of living things.

The correct answer is IV, which stands for Independent Variable. In an experiment, the independent variable is the factor that is manipulated or changed by the researcher. It is the variable that is hypothesized to have an effect on the dependent variable. The dependent variable, on the other hand, is the variable that is measured or observed to determine the outcome or effect of the independent variable. Therefore, in this question, the change refers to the independent variable.

The appropriate sequence is Transcription-Translation- etc. This sequence is correct because transcription is the process of copying the DNA sequence into RNA, and translation is the process of converting the RNA sequence into a protein. These two processes occur in sequential order in the central dogma of molecular biology. Therefore, transcription should always occur before translation.

The given correct answer states that Prokaryotes are simpler. This is true because prokaryotic cells lack a nucleus and membrane-bound organelles, making them structurally simpler compared to eukaryotic cells. Prokaryotes have a single circular chromosome, while eukaryotes have multiple linear chromosomes. Additionally, prokaryotes have a smaller size compared to eukaryotes. Therefore, the statement accurately highlights a difference between prokaryotes and eukaryotes in terms of their complexity and size.

Francesco Redi is the correct answer because he conducted experiments in the 17th century that disproved the theory of spontaneous generation of large organisms. Redi's experiments involved placing meat in jars, some covered and some uncovered, to observe the presence or absence of maggots. He found that maggots only appeared in the uncovered jars where flies could lay their eggs, thus proving that living organisms do not spontaneously generate but rather come from preexisting life.

The mRNA sequence that matches the given DNA sequence is UAG CUC. In mRNA, the base Thymine (T) is replaced by Uracil (U). So, the DNA sequence ATC GAG becomes the mRNA sequence UAG CUC.

The AUG code is a codon that stands for the amino acid Methionine. Methionine is an essential amino acid that plays a crucial role in protein synthesis and various metabolic processes in the body. It is often the starting amino acid in the formation of a polypeptide chain during translation. Methionine is also involved in the synthesis of other important molecules such as S-adenosylmethionine (SAM), which serves as a methyl donor in various biochemical reactions.

Frameshift mutation is the correct answer because the addition or deletion of a base in the DNA sequence causes a shift in the reading frame during translation. This results in a completely different amino acid sequence being produced, leading to a significant change in the resulting protein's structure and function. Point mutation, on the other hand, refers to a change in a single nucleotide base pair, which may or may not have a significant impact on the protein's structure and function.

Yes, a polymer and a macromolecule are the same thing. A polymer is a large molecule composed of repeating subunits called monomers, and a macromolecule refers to any large molecule, including polymers. Therefore, all polymers can be considered macromolecules.

Enzymes are known for their ability to speed up chemical reactions by lowering the activation energy required for the reaction to occur. They do this by binding to the substrate and facilitating the formation of the transition state, making it easier for the reaction to proceed. Enzymes are not involved in breaking down proteins, as that is the role of proteases. Therefore, the correct answer is that enzymes speed up the process and reduce the energy needed.

Water is able to dissolve many substances because of its polarity. Water molecules have a slightly positive charge on one end and a slightly negative charge on the other end. This allows water molecules to attract and surround other charged or polar molecules, effectively breaking them apart and dispersing them throughout the water. This ability to interact with both positive and negative charges makes water an excellent solvent for a wide range of substances.

Capillary action refers to the ability of water to move against gravity in narrow spaces, such as in plants' roots or in a thin glass tube. This property is due to water's cohesive forces and adhesive forces. Cohesion allows water molecules to stick together, while adhesion allows water molecules to stick to other surfaces. These forces enable water to climb up narrow spaces, defying gravity. Therefore, the statement "Water has capillary action" is a correct property of water.

Approximately 2/3 of the cell is made up of water. This means that out of the total composition of the cell, water constitutes around two-thirds of it.

The eyepiece, also known as the ocular lens, is responsible for magnifying the sample by 10X.