This is the 4th MDCAT mock test. This test will cover the following subjects and topics.
Diversity among animals
There is great diversity among animals, both in terms of their physical appearance and in their behavior. This diversity is a result of the process of evolution, which has produced a wide variety of different species that are adapted to different environments. Adaptations include changes in size and shape, as well as changes in physiology (internal body chemistry). Some types of animals live on land while others live underwater or in the air. Other adaptations allow certain types of animals to move about during the day, while others cannot move at all but must wait for nightfall. For example, some amphibians have evolved special methods of reproduction so they can lay eggs in water instead of on land. On the other hand, fish reproduce by releasing sperm and eggs into the water where fertilization takes place. When we study animal diversity concerning classifications based on ancestry, we discover that there are four major divisions: mammals, birds, reptiles, and amphibians.
Enzymes are crucial to every biological process. They help catalyze reactions and speed up the metabolic process. There are three main types of enzymes: protein, nucleic acid, and lipid. Protein enzymes are the most common. The protein portion is made up of 20 different amino acids that combine to form a long chain or molecule with a globular shape at one end and a tail at the other end.
Electrochemistry is the study of reactions that take place at the interface between an electrolyte and a conductor. Examples of this are oxidation-reduction reactions, electroplating, corrosion, and electrowinning. The formal definition of electrochemistry is the science of electrons in solution. When solving problems on this topic, remember to think about the free energy (ΔG) equation for chemical reactions. When ΔG = 0, then the reaction will proceed spontaneously and will occur if all reactants are present. For ΔG to be greater than zero, we need to add an external voltage source.
One of the most important forces that dictate how atoms interact with each other is chemical bonding. This force is what allows atoms to share electrons and form molecules. There are several types of chemical bonds, but the most common are ionic, covalent, and metallic bonds. Ionic bonds occur when one atom transfers an electron to another atom, resulting in a positively charged ion and a negatively charged ion.
Covalent bonds occur when two atoms share electrons, and metallic bonds occur when electrons flow freely between metal atoms. Lastly, there are non-covalent interactions which can be either weak or strong depending on their nature. The three main weak interactions are hydrogen bonding, van der Waals Forces, and electrostatic interactions. The first type of weak interaction involves the hydrogen atom sharing an electron bond with another electronegative atom like oxygen or fluorine. Van der Waals Forces result from temporary dipoles being created as polar atoms come close together.
Thermodynamics is the study of the flow of energy, heat, and work. Energy can be transferred in many forms such as heat, light, sound, chemical reactions, and electricity. Energy is a result of two or more processes occurring at the same time. For example, when you are burning a piece of wood with oxygen to make charcoal (carbon), you are transferring the chemical energy in the wood to the chemical energy in carbon dioxide and water vapor.
- Mistakes in sentences or short written texts
- Short-written text and select the most appropriate responses
- Course of action
- Cause & effect