DAT Review Questions (Dental Admissions)

The term "abiotic" refers to non-living factors in an ecosystem. Grass, on the other hand, is a living organism and therefore cannot be considered an abiotic factor. Temperature, wind, and water are all examples of abiotic factors as they are non-living components that can affect the ecosystem.

The lipid bilayer is a characteristic feature of cell membranes and nuclear membranes, as they both consist of a double layer of lipids. However, viruses do not have a lipid bilayer. Instead, they have a protein coat called a capsid that surrounds their genetic material. Therefore, the correct answer is "All of the above" because all options except for viruses are made of a lipid bilayer.

The statement "Light and dark reactions are two of the three stages of photosynthesis" is false because photosynthesis consists of two main stages: the light-dependent reactions and the light-independent reactions (also known as the Calvin cycle). The light-dependent reactions occur in the thylakoid membrane of the chloroplast and require light energy to produce ATP and NADPH. The light-independent reactions take place in the stroma of the chloroplast and use the ATP and NADPH produced in the light-dependent reactions to convert carbon dioxide into glucose. Therefore, the correct answer is that the statement is false because there are actually two stages of photosynthesis, not three.

Protein language consists of 20 amino acids. Amino acids are the building blocks of proteins, and they are linked together in a specific sequence to form a protein. There are 20 different types of amino acids that can be used to create proteins, each with its own unique properties. This limited number of amino acids allows for a diverse range of proteins to be formed, each with its own specific structure and function.

Water does have surface tension, which is the cohesive force that holds its molecules together at the surface. This allows water to form droplets and create a meniscus in a graduated cylinder. Surface tension is caused by the strong hydrogen bonding between water molecules.

The endoderm is responsible for the development of the lungs. During embryonic development, the endoderm gives rise to the epithelial lining of the respiratory system, including the lungs. The endoderm also forms other organs such as the liver, pancreas, and digestive tract. However, in this question, the correct answer is specifically the lungs.

Adaptive radiation refers to the process where a single species evolves into multiple species in order to adapt to different ecological niches. In this case, Darwin's Finches, Cichlids of the African Great Lakers, and Malawi Cichlids are all examples of adaptive radiation because they have diversified into different species to occupy various niches in their respective habitats. However, Tangayika Cichlids are not an example of adaptive radiation because they are not a distinct group of species that have evolved from a common ancestor to adapt to different niches.

The given answer is false because sieve-tube members in the phloem are actually highly abundant in cytoplasm, not nuclei. The nuclei in sieve-tube members are reduced or absent altogether to allow for more space for the flow of sugars and other nutrients through the tubes.

An enzyme is said to be complete if it has a cofactor. A cofactor is a non-protein molecule that is required for the enzyme to function properly. It can be either an inorganic ion or an organic molecule. The cofactor helps in the catalytic activity of the enzyme by assisting in the binding of the substrate or by participating in the chemical reaction. Without a cofactor, the enzyme may not be able to perform its function effectively. Therefore, the presence of a cofactor is necessary for an enzyme to be considered complete.

Translation is the process by which proteins are synthesized using the information encoded in RNA molecules. During translation, the ribosome reads the mRNA sequence and assembles amino acids in the correct order to form a protein. This process occurs in the cytoplasm of the cell and is essential for protein synthesis. Transcription, on the other hand, is the process of synthesizing RNA from a DNA template, while translocation refers to the movement of molecules within a cell. Transduction is the transfer of genetic material from one bacterium to another through a virus.