Latest Biological Science Reviewer 4 - LET EXAM - Questions & Answers

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Latest Biological Science Reviewer 4


1. Which of the following correctly represents the order of organization of an animal’s body?

A. Cells, tissues, organs, organs system
B. Cells tissue, organ system, organs
C. Organs system, tissue, organs, cells
D. Organs system, organs, cells, tissues

Ans: A. Cells, tissues, organs, organs system
- Specialized cells functions together to from tissues. Tissues build organs and interacting organs from organ systems.

2. Stomach, skin, and liver area examples of ___________.

A. cells
B. organs
C. organ system
D. tissues

Ans: Group of organs that work together that performs specific functions for the organism make up the organ systems. Stomach and liver are organs of the digestive system while is an organ of integumentary system.

3.Which of the following is the function of epithelial tissues?

A. Join together body structures
B. Covers the body and its organs
C. Carries information throughout
D. Contact in responses to signals from spinal cord and brain

Ans: B. Covers the body and its organs
- Most animals have four types of tissue: epithelial, connective, muscle and nervous. Epithelial tissues cover the body and its organ. These tissues protect the underlying tissues sense. Stimuli and secrete substance. Connectve tissues join together body structures providing support. Muscle Tissues consist of cell that provides  protection and support. The exoskeleton of arthropods are made up of a layer of non-living material known as chitin. An internal hard skeleton is called endoskeleton.

4. Which is a description of endo skeleton?

A. It is an internal hard skeleton
B. It does not contain hard structures such as bones
C. It is composed of a layer of non-living material called chitin
D. It is a support system consisting of a body compartment filled with fluid under pressure

Ans: A. It is an internal hard skeleton
- Various groups of animal have evolved with three distinct type of skeletons. A hydrostatic skeleton is a support system consisting of a body compartment filled with fluid under pressure. Unlike human skeleton, they do not contain any hard structures like bones. An exoskeleton is a hard covering on the outside of the body that provides protection and support. The exoskeleton of arthropods are made up of layer of non-living material known as chitin. An internal hard skeleton is called endoskeleton.

5. Which of  the following belong to axial skeleton?
I. Skull
II. Arm bones
III. Vertebal column
IV. Rib cage


Ans: D. I, III and IV
- The human skelton is divided into two main groups or categories of bones axial and appedicular. The Axial skeleton consist of the skull, hyoid bone, auditory ossicles vertebral column (also called the spine or backbone) sternum bone and ribs (which together with the sternum form the throat’). The arm and leg bones of the pelvis and should areas, form the appendicular skeleton.

6. Which are finger like projections that lines the small intestine making absorption more efficient?

A. Chyme
B. Colon
C. Peristalsis
D. Villi

Ans: D. Villi
- Villi are finger projection that line the internal surface of the small intestine, increasing its surface area making absorption more efficient. Chyme is a soft pulp in the stomach made up of acids and partially digested proteins and carbohydrates. Peristalsis is the successive wave of smooth muscle contractions in the esophagus wall.

7. Where is digestion of carbohydrates, proteins and fats completed?

A. Large intestine
B. Mouth
C. Small intestine
D. Stomach

Ans: C. Small intestine
- After about three hours in the stomach, food is reduced to chime which is composed of acids, partially digested proteins and carbohydrates and undigested fats. In the small intestine are absorb. In the large intestine, water and water-soluble vitamins are absorb from undigested material.

8. Which is NOT a function of the integumentary system?

A. Taking in nutrients
B. Retarding water loss
C. Regulating body temperature
D. Preventing the entry of microorganisms

Ans: A. Taking in nutrients
- The integumentary  system  covers the body and consis of the skin, it glands hair  and nails. Choices B, C and D are important functions of the integumenary system. Choice A taking in nutrients is a function of the digestive system.

9. Which layer of epidermis is found on the palms of our hands and soles of our feet?

A. Stratum basale
B. Stratum corneum
C. Stratum granulosum
D. Stratum lucidum

Ans: D. Stratum lucidum
- The epiderm is the outer layer of the skin. Is made up of four to five main layers. Stratum Lucidum also known as “Thick skin” because it has five epidermal layers instead of four. This layer is only easily found in certain hairless parts of our body namely the palms of our hand and the sole of our feet. The stratum basale also calledthe stratu germinativum, is the basal (base) layer of the epidermis. The stratum spinosum is partly responsible for the skin’s strength and flexibility. The stratum corneum is the only layer of skin we see with or eyes.

10. What are tiny sacs within the lungs that allow oxygen and carbon dioxide to move between the lungs and bloodstream?

A. Alveoili
B. Bronchiloles
C. Larynx
D. Pharynx

ANS: A. Alveoili
- Air gets inside the body and passes through a series of tubes. The first tube that air enters is the pharynx branches into the esophagus a tube that leads to the stomach and the larynx. Leads to the trachea, the main passage way to the lungs. The trachea braches into  two main section each called a bronchus. Each of these bronchi  then branch into more bronchi. Those, in turn branch into smaller tubes called bronchioles. At the end of each of the many tiny branches of our bronchial tree, we find occurring between the circulatory and respiratory system takes place in the alveoli.

11. What is the role of pleurae in the respiratory system?

A. To produce mucus
B. To facilitate gas exchange
C. To protect and lubricate the lungs
D. To destroy foreign bodies in the lungs

Ans: B. To facilitate gas exchange
- Pleurae are serous membrane that enfold both lungs and are reflected upon the walls of the thorax and diaphragm. The pleurae are moistened with a serous secretion that reduces friction thereby protecting and lubricating the lungs during respiratory.

12. Which is the correct sequence of urine formation?

A. Secretion-Filtration-Reabsorption
B. Filtration-Reabsorption-Secretion
C. Filtration-Secretion-Reabsorption
D. Reabsorption-Filtration-Secretion

Ans: B. Filtration-Reabsorption-Secretion
- Urine is formed through a combination of four basic process: 1) glomerular filtration 2) tubular secretion and 4) water conservation. As blood flows through the glomerulus, blood pressure pushes water and solutes from the capillaries into the capsule through a filtration membrane. This fluid is called filtrate. As the filtrate moves along the tubules, it is called a tubular fluid. Most of the water and many other molecules are reabsorb into the blood, while some substances are secreted into the tubular fluid. Once the fluid, moves into the collecting duct, it is called urine. While in the collecting duct, additional water is removed from the urine concentrating the wastes.  

13. All of the following are parts of the urinary system EXCEPT

A. gallbladder
B. kidney
C. ureters
D. urethra

Ans: A. gallbladder
- Gallbladder is part of the digestive system. The gallbladder  holds bile produced in the liver until it is needed for digesting fatty foods in the duodenum of the small intestine. The kidneys remove wastes from the blood and process them into urine. Ureters are narrow tubes carry urine from the kidney to the bladder. Urethra is a tube that follows urine to pass outside the body.

14. Where does exchange of materials between the blood and surrounding  tissues takes place?

A. Arteries
B. Atrium
C. Capillaries
D. Veins

Ans: C. Capillaries
- Most of the exchange of gases, nutrients and waste happen by diffusion through the thin capillary walls. Arteries are blood vessel that carry blood away from the heart. They deliver oxygen-rich blood from the heart to the tissues of the body. Blood returns to the heart in veins. The atrium is the upper chamber in which blood enters the heart.

15. Which of the following secrete antibodies specific to combat infectious microorganisms and other foreign substances?

A. Antioventricular node
B. Diastole
C. Sinoatrial mode
D. Sytole node

Ans: D. Sytole node
- Nodes are masses of nerve and muscle cells send out electrical signals that control the heart beat. The impulse of contraction of the heart originates in the sinoatrial node or SA node located in the right atrium close to the point of entry of the vena cava. The SA node’s dignal travels to the atrioventicular node or AV node that signals the ventricles to contract. A heartbeat has two part, the systole and the diastole. Systole is the contraction of the heart and the time  when the heart muscle is a pumping blood. Diastole is the time when the heart muscle is relaxing and filling up again with blood.

16. Which of the following secrete antibodies specific to combat infectious microorganism and other foreign substance?

A. Lymphocytes
B. Macrophage
C. Micropage
D. Phagocytes

And: A. Lymphocytes
- Lymphocytes are leukocytes (white blood cells) necessary in the immune system because they secrete antibodies specific  to different  invading pathogens.

17. Which term in anatomy means cluster of nerve cells?

A. Axons
B. Dendrites
C. Ganglia
D. Neurons

Ans: C. Ganglia
- Gangalia are nerve cell cluster situated in the autonomic nervous  system and sensory system. Neurons are the basic units of the nervous system and its most important part is the brain. Every neuron contains a soma or cell body, which contains the nucleus; an axon, which carries an electric impulse; and one more dendritic trees, which typically receive input.


18. Which is the main function of interneurons?

A. Sends information across the synapse
B. Conduct impulses within the central nervous system
C. Conduct impulses away from the central nervous
D. Which is the main function of interneurons

Ans: B. Conduct impulses within the central nervous system
- There are different types of neurons based on function. Sensory neurons conducts nerve impulses toward the central nervous system. Motor neurons conduct from the nervous system. Interneurons conduct impulses within the central nervous system. Interneurons connect with sensory neurons, motor neurons.

19. Which glands secretes melatonin which controls body function in response to daylight changes?

A. Adrenal glands
B. Parathyroid gland
C. Pineal gland
D. Thyroid gland

Ans:  C. Pineal gland
- The pineal gland also called conarium, produce melatonin s serotonin derived hormone which modulate sleep patterns in both circadian and seasonal cycles. Rene Descartes described the pineal gland as the “principal seat of the soul” Many called it the “third eye”. It sits alone in the middle of the brain and at the same level as the eyes.

20. Which hormone regulates the retention of water in the kidney?

A. Glucagon
B. Oxytocin
C. Thymosin
D. Vasopressin

Ans: D. Vasopressin
- Antidiuretic hormone (ADH) also known as vasopressin is a hormone made by the hypothalamus in the brain and stored in the posterior pituitary gland. It tells the kidneys how much water to conserve. Dehydration triggers the release of ADH from the posterior pituitary and the kidneys in response retain water from the blood that filter through  the kidneys. Without ADH or when it is suppressed by alcohol, the kidneys do not retain water  form the blood and most of th water leaves the body in the urine.

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