ATI TEAS Practice Science Test

Correct Answer: A

Rationale: The correct answer is A: Embryogenesis. During the first trimester of gestation, the developing organism goes through the process of embryogenesis, where the embryo forms and major organ systems begin to develop. Fertilization (B) occurs at the beginning of pregnancy, not during the first trimester. Meiosis (C) is the process of cell division that produces gametes, not directly related to the first trimester of gestation. Menstruation (D) is the shedding of the uterine lining if fertilization does not occur, not a developmental process during pregnancy.

Correct Answer: B

Rationale: The correct answer is B because urine is formed in the kidney during the process of fluid filling the collecting duct. This is where the final concentration and composition of urine are regulated. Before reaching the collecting duct, the initial filtration of blood occurs in the glomerulus (eliminating options C) and the fluid does not become urine until it has passed through the collecting duct (eliminating options A and D). So, the correct sequence is filtration in the glomerulus, reabsorption and secretion in the tubules, and final urine formation in the collecting duct.

Correct Answer: B

Rationale: The correct answer is B: Ribcage. The ribcage is a bony structure that surrounds and protects the lungs. It consists of ribs, sternum, and thoracic vertebrae, forming a protective cage around the vital organs in the thoracic cavity. The ribs provide a barrier against external forces and help maintain the shape and integrity of the lungs. The other choices are incorrect because the femur is a bone in the leg, the scapula is a bone in the shoulder, and the skull protects the brain, not the lungs.

Correct Answer: C

Rationale: The correct answer is C: Hypothalamus. The hypothalamus is a major structure of the limbic system responsible for regulating various essential functions like emotions, behavior, and physiological processes. It plays a crucial role in the control of thirst, hunger, body temperature, and hormonal regulation. The brainstem (A) is involved in basic life functions like breathing and heart rate, but it is not a part of the limbic system. The spinal cord (B) primarily functions in transmitting sensory and motor signals but is not directly related to the limbic system. The cerebral cortex (D) is responsible for higher-order thinking, sensory processing, and motor functions but is not a major structure of the limbic system.

Correct Answer: B

Rationale: The correct answer is B: Smallpox. Smallpox was eradicated through a global vaccination campaign led by the World Health Organization. This disease was declared eradicated in 1980 due to the success of mass vaccination programs. AIDS (A) is caused by the human immunodeficiency virus (HIV) and does not have a vaccine. Diabetes type 1 (C) and rheumatoid arthritis (D) are chronic conditions that cannot be eliminated through vaccination programs.