Biology Midterm 2022-2023

Substance A is converted to substance B in a metabolic reaction. Which statement BEST describes the roles of an enzyme during this reaction?

• It adjusts the pH of the reaction medium.

• It provides energy to carry out the reaction.

• It dissolves substance A in the reaction medium.

• It speeds up the reaction without being consumed.

Which example is an activity that a fish MOST LIKELY uses to maintain homeostasis within it body?

• Using camouflage to avoid predators.

• Feeding at night to regulate body temperature.

• Moving to deeper water to regulate metabolic wastes.

• Exchanging gases through its gills to regulate oxygen levels.

Scientists observed that the populations of top-level consumers in a particular ecosystem were rapidly decreasing. Further studies revealed that there was also a decline in producer productivity. Which other changes did the scientists most likely observe in the ecosystem?

• increased producer diversity

• decreased population size at all levels

• decreased primary consumer populations only

• increased primary and secondary consumer diversity

Carbon can combine with many different elements but frequently combines with oxygen, hydrogen, and nitrogen to form organic molecules. Which statement best explains why carbon is able to form a large number of different molecules?

• carbon forms only ionic bonds

• carbon can form only ring structures

• carbon can form four covalent bonds

• carbon forms small, simple structures

Which statement correctly describes how a protein is formed?

• a monosaccharide bonded to a side chain is broken apart

• amino acids are bonded together in a long chain to form a new molecule

• a molecule containing glycerol bonded to three fatty acids is broken apart

• a nitrogenous base, a sugar, and a phosphate group combine to form a new molecule

A group of students is given a sample of an unknown substance. The students are asked to gather evidence to determine whether the substance is living or nonliving. The students take a small sample of the substance and observe it using a microscope. What characteristics of the substance that can be observed to indicate whether it is living or nonliving.

• the substance is made up of water.

• the substance responds to stimuli

• the substance is made up of carbon atoms

• the substance is green

Most prokaryotes and eukaryotes maintain a reserve of ATP. Which feature of prokaryotes and eukaryotes makes the ATP reserve necessary?

• they have cell membranes

• they can change over time

• they use energy to function

• they have the ability to reproduce

Which structure and function are common to all plants and some protists and distinguish them from all animals?

• chloroplasts that conduct photosynthesis

• mitochondria that conduct photosynthesis

• chloroplasts that conduct cellular respiration

• mitochondria that conduct cellular respiration

Cellulose is a carbohydrate and a polymer of glucose. Which statement best describes how cellulose is formed within living organisms?

• It is assembled by bonding individual atoms.

• It is constructed by connecting smaller monomer subunits.

• It is the product of the decomposition of a much larger molecule.

• It is the result of a physical change that alters the shape of a compound.

Which of the following conclusions can be drawn from this graph?

• The optimum pH of the enzyme is 6.6.
  
• The optimum pH of the enzyme is 5.8
  
• The enzyme’s activity increases as pH increases 5.0 to 9.0
  
• The enzyme’s activity is greater around pH of 8.0 .