Question

QUESTION 70

1. Water is an excellent solvent for living things because

   	A.	compounds with ions like sodium as well as polar molecules like glucose readily dissolve in water.
   	B.	it is semisolid at body temperature, preventing it from flowing freely through the human body.
   	C.	it maintains an unstable temperature for chemical reactions to occur.
   	D.	it can rearrange its bonds forming a new substance

1.5 points   

QUESTION 71

1. What do we find in the nucleus of an atom?

   	A.	electrons and protons
   	B.	electrons
   	C.	protons only
   	D.	neutrons and electrons
   	E.	protons and neutrons

1.5 points   

QUESTION 72

1. Which major digestive process involves nutrient molecules passing from the GI tract into the blood? (they're not asking about the actual breakdown of food)

   	A.	secretion
   	B.	absorption
   	C.	digestion
   	D.	mechanical processing and movement
   	E.	elimination

1.5 points   

QUESTION 73

1. Which one of the following activities would be facilitated by the  sympathetic nervous system?

   	A.	decreased respiratory rate
   	B.	increased bladder contraction
   	C.	increased blood pressure
   	D.	decreased heart rate
   	E.	increased digestion and absorption

1.5 points   

QUESTION 74

1. Which one of the following cells transmit impulses away from the central nervous system to the muscles and other organs?

   	A.	sensory neurons
   	B.	motor neurons
   	C.	dendrites
   	D.	none of the above
   	E.	neuroglia

1.5 points   

QUESTION 75

1. Which one of the following components is needed to synthesize a new strand of  DNA?

   	A.	disaccharides
   	B.	glucose
   	C.	nucleotides
   	D.	amino acids
   	E.	lipids

1.5 points   

QUESTION 76

1. Which one of the following divisions of the nervous system is active during the relaxed (resting) state?

   	A.	somatic division
   	B.	fight or flight division
   	C.	parasympathetic division
   	D.	sympathetic division
   	E.	endocrine division

1.5 points   

QUESTION 77

1. Which one of the following forms of birth control reduces the risk of transmission of sexually transmitted diseases?

   	A.	birth control pill
   	B.	hysterectomy
   	C.	IUD
   	D.	condom
   	E.	hysteroscopy

1.5 points   

QUESTION 78

1. Which one of the following forms the  major portion of the  bilayer structure that is found in cell membranes?

   	A.	amino acids
   	B.	phospholipids
   	C.	saturated fats
   	D.	carbohydrate
   	E.	triglycerides

1.5 points   

QUESTION 79

1. Which one of the following is TRUE regarding enzymes?

   	A.	Enzymes are not that important in reactions.
   	B.	Enzyme function is not affected by changes in pH.
   	C.	Enzymes are used up in a chemical reaction, so an organism must constantly replace these enzymes.
   	D.	Each enzyme catalyzes one specific reaction or group of reactions.
   	E.	Enzyme function is not affected by changes in temperature.

Answer 1

Question 1

Option A:- Correct'

Reason:- Water makes hydrogen bonds with other molecules. The polar water molecules get attracted to the charged ions and hydrate them to dissolve. It is called a universal solvent because it is capable to dissolve a wide range of substances then compared to any other solvent.

Option B:-Incorrect

Reason:- Water remains liquid at body temperature.

Option C:-Incorrect

Option D:- Incorrect

Reason:- Water molecules form hydrogen bonding with various substances =. The water molecule keeps on rearranging and making hydrogen bonding with the neighboring atoms.

Question 2

Option A:- Incorrect

Reason:-Electrons are present in the outer orbitals whereas the protons are present inside the nucleus.

Option B:- Incorrect

Reason:- Electrons are found in orbitals around the nucleus.

Option :- Incorrect

Reason:= They are present inside the nucleus along with neutrons.

Option D:-Incorrect

Reason:- Neutrons are present in the orbital outside the nucleus.

Option E:- CORRECT

Reason:- Neutrons are protons both are positively charged particles and these are present in the nucleus whereas the electron surrounds the nucleus.

Question 77

Option:- Incorrect

Reason:- The birth control pills are only useful in case of avoiding unwanted pregnancy.

Option B:- Incorrect

Reason:- Hysterectomy involves the removal of uterus whereas sexually transmitted diseases are transmitted from one person to another by the exchange of body fluids like semen, blood, etc.

Option C:- Incorrect

Reason:- Intrauterine devices are birth control techniques. It prevents pregnancy by avoiding the movement of sperm in the uterus.

Option D:- CORRECT

Reason:- Condoms are made up of latex and they act as a physical barrier to avoid direct contact and transfer of body fluid between two people. Hence it has a dual role: It is a contraceptive method as well as prevents sexually transmitted diseases like Herpes, syphilis, and HIV-AIDS.

Option E:- Incorrect

Reason:- It is a process that always the doctor to look inside the uterus by using a telescope and lens in order to diagnose complications.

Question 78

Option B:- Correct

Reason:- The cell membrane is made up of phospholipid bilayer that contains two layers of phospholipids.

Question 79

Option A:- Incorrect

Reason:- Enzymes are the chemical catalysts that accelerate the rate of the chemical reaction by lowering the activation energy of the reaction.

Option B:- Incorrect

Reason:- With increase in pH the enzymes get denatured as the enzymes are proteinous in nature. Whereas in the absence of low pH the enzymes get inactivated.

Option C:-Incorrect

Reason: Enzymes alter the rate of a reaction without being used/exhausted in the reaction.

Option D:- TRUE

Enzymes are very specific in nature. They catalyze specific chemical reactions. The specificity can be explained by the lock and key hypothesis.

Option E:- Incorrect

Reason:- Enzymes are proteinous in nature they get denatured at higher pH and temperature, Enzymes catalyze reactions only at optimum conditions.