Free GACE Biology Questions and Answers — Questions and Answers

Question 1: Which of the following has historically been utilized as a host organism to make insulin for diabetes patients?

Plant cell
Human cell
Animal cell
Bacterial cell (Correct answer)

Correct answer: Bacterial cell

Explanation: In the history of Genetic Engineering, bacterial cells have been used as a host organism to produce insulin for diabetic patients. Specifically, Escherichia coli (E. coli) bacteria have been genetically engineered to produce human insulin. The human insulin gene was cloned and inserted into the E. coli bacterial genome, allowing the bacteria to produce large quantities of human insulin. This method has been used since the 1980s and has revolutionized the production of insulin, making it more widely available for diabetic patients.

Question 2: The useable kind of energy that is utilized by living things is

NAD+
ATP (Correct answer)
ADP
Glucose

Correct answer: ATP

Explanation: The usable form of energy that living organisms use is ATP (adenosine triphosphate). ATP is a high-energy molecule that is synthesized in cells during the process of cellular respiration, which involves the breakdown of glucose and other molecules to produce ATP. ATP is used by cells to power various cellular processes, such as muscle contraction, protein synthesis, and active transport across cell membranes. When ATP is used by cells, it is hydrolyzed into ADP (adenosine diphosphate) and inorganic phosphate, releasing energy that can be used to drive cellular processes. ATP is constantly being synthesized and broken down in cells to maintain the energy balance required for life processes.

Question 3: Which of the following endomembrane system components produces lipids and steroid hormones?

Smooth endoplasmic reticulum (Correct answer)
Golgi apparatus
Rough endoplasmic reticulum
Lumen

Correct answer: Smooth endoplasmic reticulum

Explanation: The smooth endoplasmic reticulum (ER) is responsible for the synthesis of lipids and steroids in the endomembrane system of a cell. The smooth ER lacks ribosomes and appears smooth under a microscope. It plays a variety of roles in the cell, including the synthesis of lipids, such as phospholipids and cholesterol, which are important components of cell membranes. Additionally, the smooth ER is involved in the detoxification of drugs and toxins, the storage of calcium ions, and the metabolism of carbohydrates. In specialized cells, such as those in the adrenal gland, the smooth ER is responsible for the synthesis of steroid hormones.

Question 4: When is adenine swapped out for guanine, which point mutation occurs?

Insertion
Deletion
Transition (Correct answer)
Transversion

Correct answer: Transition

Explanation: The substitution of adenine (A) with guanine (G) is a type of point mutation known as a transition. In a transition mutation, a purine (adenine or guanine) is replaced by another purine, or a pyrimidine (cytosine or thymine) is replaced by another pyrimidine. In this case, adenine and guanine are both purines, so the substitution represents a transition mutation. Transition mutations are one of two types of point mutations, the other being transversion mutations, in which a purine is replaced by a pyrimidine, or vice versa.

Question 5: Which of the following point mutations happens when guanine replaces adenine?

Telomere
Q arm
P arm
Centromere (Correct answer)

Correct answer: Centromere

Explanation: The centromere is the part of a chromosome that holds the sister chromatids together. The centromere is a region of DNA located near the middle of the chromosome, where the two identical sister chromatids are joined together by protein structures called kinetochores. The kinetochores attach to spindle fibers during cell division, allowing the chromosomes to be separated and pulled to opposite ends of the cell. The centromere also plays a role in ensuring that each daughter cell receives the correct number of chromosomes during cell division. Chromosome abnormalities, such as deletions, inversions, or translocations of the centromere, can lead to genetic disorders or developmental abnormalities.

Question 6: An Ao blood-type male marries a Bo blood-type woman. Which of the following indicates the likelihood of conceiving a child with the blood type OO?

75%
25% (Correct answer)
0%
50%

Correct answer: 25%

Explanation: If a man with Ao blood type (genotype AO) marries a woman with Bo blood type (genotype BO), their offspring can inherit one of four possible blood types: AO, BO, AB, or OO. The A and B blood type alleles are co-dominant, meaning that if an individual inherits both alleles (AB), both types of antigens will be expressed.

Question 7: Our genetic material is held together by a main carbohydrate, which is known as ____. This sugar does NOT lack an oxygen or hydroxyl group on one of its carbons.

Ribose (Correct answer)
Glucose
Deoxyribose
Fructose

Correct answer: Ribose

Explanation: The primary carbohydrate that helps hold our genetic materials together is ribose. Ribose is a type of sugar that is a component of RNA (ribonucleic acid) and plays a key role in the structure and function of RNA molecules. Ribose is a monosaccharide that has five carbon atoms and is a type of pentose sugar. Unlike deoxyribose, which lacks an oxygen atom on the 2' carbon, ribose has a hydroxyl (-OH) group attached to each of its carbon atoms. These hydroxyl groups participate in the formation of phosphodiester bonds that link the nucleotides together in the RNA molecule, forming the backbone of the RNA strand.

Question 8: Due to the hydrogen bonding between its molecules, water is beneficial:

Liquid for lipids
Member of replacement reactions
Surface across which tiny particles and live things can migrate. (Correct answer)
For polysaccharides like cellulose, a solvent
Instance of an acid

Correct answer: Surface across which tiny particles and live things can migrate.

Explanation: Water molecules are drawn to one another (negative pole to positive pole) and "stick" together as a result of the hydrogen bonds that exist between them. Water has a high surface tension as a result, making it possible for small living things like water striders to move over its surface. Because it is a polar molecule, water easily dissolves other polar and ionic compounds like amino acids and carbohydrates. However, being polar does not guarantee that a substance will be soluble in water; for instance, cellulose is polar yet its molecular weight is so high that it is not soluble in water.

Question 9: Energy is released during a disaccharide breakdown and is then stored as ATP. Here is an illustration of a(n):

Endothermic reaction (Correct answer)
Combination reaction
Replacement reaction
Exothermic reaction
Thermodynamic reaction

Correct answer: Endothermic reaction

Explanation: In contrast to endothermic reactions, exothermic reactions produce energy. An illustration of a decomposition reaction is when a chemical substance breaks down (AB → A + B). The opposite of a decomposition reaction is a combination reaction (A + B→ AB), while a replacement (displacement) reaction is when a compound disintegrates into a new compound and a free reactant (AB + C → AC + B or AB + CD → AD + CB).

Question 10: Which of the following molecules used in metabolism solely contains carbon, oxygen, and hydrogen?

Glycogen (Correct answer)
Phospholipids
Peptides
RNA
Vitamins

Correct answer: Glycogen

Explanation: A polysaccharide, or molecule made up of several linked glucose molecules, is glycogen. All carbohydrates include solely carbon, oxygen, and hydrogen, therefore glucose is a type of carbohydrate. Other atoms are present in the majority of other metabolic molecules, especially in nitrogen, phosphorus, and sulfur.

Question 11: Over time, if an animal consumes more energy than it expends, the excess chemical energy is stored as:

Starch
Protein
Enzymes
Fat (Correct answer)
Cholesterol

Correct answer: Fat

Explanation: Animals store long-term energy in the form of fat. Starch is another kind of energy storage for animals, although these materials are only used temporarily. Because fatty acids bind to glycerol in a condensation reaction to generate lipids, fats are a good form of energy storage (triglycerides). A concentrated form of high-energy fatty acids can be compacted because to this process, which also releases water.

Question 12: Which of the following are created when a particle from outside the cell is encircled by the plasma membrane?

Golgi bodies
Rough endoplasmic reticulum
Lysosomes
Endocytic vesicles (Correct answer)
Secretory vesicles

Correct answer: Endocytic vesicles

Explanation: Larger molecules (or even extremely small creatures, like bacteria), which would not be able to pass through the plasma membrane, are taken in by cells through the process of endocytosis. Once inside the cell, endocytic vesicles carrying chemicals from the external environment frequently go through additional processing.

Question 13: Which of the following plant organelles houses the pigments responsible for the color of leaves?

Centrioles
Chloroplasts (Correct answer)
Cell walls
Central vacuole
Golgi apparatus

Correct answer: Chloroplasts

Explanation: The light-absorbing substance chlorophyll, which is necessary for photosynthesis, is found in chloroplasts. As a result, leaves are green. Additionally, the red and yellow carotenoid pigments found in chloroplasts give leaves their fall colors of red and yellow as chloroplasts begin to lose their chlorophyll.

Question 14: Which of the following methods for transferring solutes across a plasma membrane is not one of them?

Passive transport
Active transport
Osmosis (Correct answer)
Facilitated diffusion
Endocytosis

Correct answer: Osmosis

Explanation: Water molecules—not solutes—move over a semi-permeable membrane by osmosis. Water also moves from an area of greater concentration. Lower concentration area. Osmosis happens when a solute's concentrations on either side of a semi-permeable membrane differ. For instance, a cell in a salty solution will lose water as it loses water, as the cell has a higher concentration of water than the solution. This keeps happening until the external solution has the same salt content as the cytoplasm.

Question 15: Which of the following angiosperm components produces fruit?

Ovary (Correct answer)
Medical
Filament
Sepal
Meristem

Correct answer: Ovary

Explanation: In a flower, the ovules are housed in the ovary. Ovules are fertilized by pollen grains, which produce seeds, and the ovary develops into a fruit.

Free GACE Biology Questions and Answers

Which of the following has historically been utilized as a host organism to make insulin for diabetes patients?