Test Prep Test Prep Certifications OAT Questions & Answers

• Question 151:

  Jellyfish possess what type of circulatory system?

  A. Closed circulatory system

  B. Open circulatory system

  C. Dorsal vessel

  D. Double circulatory system

  E. It has no circulatory system

  Correct Answer: E

  Cnidarians (like the jellyfish) do not possess a circulatory system and use diffusion to circulate materials instead. It is vital to know the circulatory, reproductive, excretory, respiratory etc. systems of each phylum as you will be tested on it in the biology section!

• Question 152:

  Which structure is responsible for a sperm cell's motility?

  A. Cilia

  B. Flagellum

  C. Mitochondria

  D. Acrosome

  E. A and B

  Correct Answer: B

  The flagellum is responsible for propelling the sperm. The acrosome contains the digestive enzymes that break down the ovum membrane.

• Question 153:

  In a sample with 46 homologous pairs of chromosomes, what is the total number of chromatids present in the sample?

  A. 23

  B. 46

  C. 92

  D. 184

  E. 256

  Correct Answer: D

  If there are 46 homologous chromosomes present, it means there is a total of 92 chromosomes. 46 come from the father, 46 from the mother. Thus with 92 chromosomes, there is a total of 184 chromatids.

• Question 154:

  The medulla oblongata functions in regulating many things in the human body. Which of the following processes does it NOT control?

  A. Breathing rate

  B. Heart rate

  C. Blood pressure

  D. Reflexes (coughing, sneezing etc.)

  E. Movement

  Correct Answer: E

  The medulla oblongata indeed controls options breathing rate, heart rate, blood pressure, reflexes. Movement, however, is controlled by the cerebrum. The functions of each part of the brain is required to be known and is commonly tested on.

• Question 155:

  Which of the following accurately states the products of the citric acid cycle?

  A. 6 NADH, 2 FADH2, 2 ATP, 4 CO2

  B. 12 NADH, 4 FADH2, 4 ATP, 8 CO2

  C. 3 NADH, 1 FADH2, 1 ATP, 2CO2

  D. 6 NADH, 4 FADH2, 4 ATP, 4 CO2

  E. 6 NADH, 2 FADH2, 8 ATP, 4 CO2

  Correct Answer: A

  6 NADH, 2 FADH2, 2 ATP, 4 CO2 indeed describes the products of the citric acid cycle (Krebs cycle). This is a conceptual question dealing with respiration. One should know the general reactants and products of the various aerobic and anaerobic cycles dealing with respiration.

• Question 156:

  Which of the following answer choices incorrectly pairs the germ layer and the structure it gives rise to?

  A. Ectoderm – central nervous system

  B. Mesoderm – connective tissue

  C. Endoderm – liver

  D. Mesoderm – muscles

  E. Endoderm – lens of the eye

  Correct Answer: E

  The ectoderm is responsible for the formation of the lens of the eye. Know the basic structures these 3 germ layers give rise to.

• Question 157:

  Which of the following functions in regulating and allowing chyme to pass from the stomach to the duodenum of the small intestine?

  A. Cardiac sphincter

  B. Pyloric sphincter

  C. Ileocecal sphincter

  D. Esophageal sphincter

  E. Sphincter of Oddi

  Correct Answer: B

  Pyloric sphincter is indeed the function that the question describes. Sphincter of Oddi functions in allowing digestive juices (bile) through the hepatopancreatic duct. Cardiac sphincter functions between the esophagus and the stomach, preventing stomach juice (acid) from coming up the esophagus. The Ileocecal sphincter borders the small and large intestine, preventing contents from the colon spilling back into the ileum (small intestine). The esophageal sphincter functions in opening to allow food from the mouth to enter the esophagus. It is very important to know and understand the functions of these main sphincters in the body.

• Question 158:

  Which of the following functions to collect and focus the light from the illuminator on to the specimen?

  A. Illuminator

  B. Condenser

  C. Nosepiece

  D. Ocular

  E. Diaphragm

  Correct Answer: B

  Knowing the compound microscope anatomy and its functions is important for the biology section as it can and is tested.

• Question 159:

  Which of the following leukocytes function in releasing histamine as an inflammatory response and possesses large cytoplasmic granules?

  A. Neutrophil

  B. Eosinophil

  C. Lymphocyte

  D. Monocyte

  E. Basophil

  Correct Answer: E

  Basophils are indeed responsible for releasing histamine as an inflammatory response. Their structure is also indeed of having large cytoplasmic granules.

• Question 160:

  Which of the following is the largest organelle in an animal cell?

  A. Mitochondrion

  B. Chloroplast

  C. Nucleus

  D. Vacuole

  E. Golgi apparatus

  Correct Answer: C

  An animal cell has neither chloroplast nor vacuole, thus B and D can be eliminated. In an animal cell, the nucleus is indeed the largest organelle (in relation to diameter).