Question

QUESTION 1

1. Every  eukaryotic cell

   	A.	contains a prokaryotic cell
   	B.	has a cell wall composed of cellulose that serves as the outer boundary of the cell
   	C.	possesses flagella and cilia, unlike prokaryotes
   	D.	has its genetic material concentrated in a membrane-enclosed nucleus
   	E.	contains  all of its genetic material in mitochondria

1.5 points   

QUESTION 2

1. A codon is

   	A.	a type of DNA repair enzyme
   	B.	a sequence of nucleotides that makes up a whole gene
   	C.	the part of the ribosome to which mRNA attaches
   	D.	a form of birth control for male or female
   	E.	a sequence of three nitrogenous bases on mRNA that corresponds to an amino acid

1.5 points   

QUESTION 3

1. A disorder of the nervous system in which the individual has an inflammation of the layers that surround the brain is called:

   	A.	meningitis
   	B.	lactose intolerance
   	C.	overnutrition
   	D.	Encephalitis
   	E.	shingles

1.5 points   

QUESTION 4

1. A molecule used by the body in a Specific Response is an immuniglobulin (I _gG), it is a class of  molecules known as

   	A.	NK cells
   	B.	CD 8 cells
   	C.	CD4 cells
   	D.	antibodies

1.5 points   

QUESTION 5

1. A neuron at rest has a charge difference across its cell membrane, with the interior of the cell negative relative to the exterior. This difference in charge across the plasma membrane is referred to as ________ membrane potential

   	A.	graded
   	B.	action
   	C.	depolarization
   	D.	refractory
   	E.	resting

Answer 1

Answer for question no 1 : Option (D) - Has its genetic material concentrated in a membrane - enclosed nucleus

Explanation : Eukaryotic cell is characterised by membrane bound nucleus and cell organelles. The genetic material in eukaryotic cell is compartmentalised and found to be concentrated in the nucleus.

So, Option (D) is the right answer.

Option (A) is not the right answer because in a few eukaryotic cells, a symbiotic Prokaryotic cell is present inside. This is not seen in every eukaryotic cells.

Option (B) is not the right answer cellulose is not the only material by which an eukaryotic cell wall is composed of. Moreover there are eukaryotic cells which don't have cell wall at all.

Option (C) is not the right answer as Prokaryotic cells do possess flagella and cilia but not every eukaryotic cell contain flagella and cilia.

Option (E) is not the right answer as eukaryotic cells contain distinct genetic material apart from mitochondrial DNA, stored in their nucleus.

Answer for question no 2 : Option (E) - A sequence of 3 nitrogenous base son mRNA that corresponds to an amino acid.

​​​​​​Explanation :

A codon is a continuous stretch of three nitrogenous bases on mRNA which codes for different amino acid upon translation, based on the sequence of the codon.

So, Option (E) is the right answer.

Option. (A) is not the right answer because a codon is a three nucleotide sequence, its not an enzyme.

Option (B) is not the right answer as a codon doesn't makeup the whole sequence of nucleotides of a gene.

Option (C) is not the right answer as a codon is a part of nucleotide sequence, not a part of ribosome.

Option (D) is not the right answer as a codon has no function in birth control.

Answer for question no 3 : Option (A) - Meningitis

Explanation :

Meningitis is a disease in which inflammation of membrane (meninges) that surrounds brain and spinal cord occurs.

So, Option (A) is the right answer.

Option (B) is not the right answer as lactose intolerance is a metabolic disorder. It's not a disorder of brain or nervous system.

Option (C) is not the right answer as Overnutrition is not a disorder of nervous system.

Option (D) is not the right answer as in encephalitis the inflammation is in the brain not in the layers surrounding the brain.

Option (E) is not the right answer as Shingles are a type of rash shown by reactivated chicken pox virus that is not related to inflammation of the layers surrounding the brain.

Answer for question no 4 : Option (D) - Antibodies

Explanation :

The immunoglobulin(IgG) is used by the body in a specific response against any antigen and this molecule is a class of Antibodies.

So, Option (D) is correct.

Option (A) is not the right answer as Immunoglobulins are not NK cell. Nk cells are a specialised cell which kills infected cells and it is a component of cellular immune response.

Option (B) and (C) are not the right answer as immunoglobulins or Antibodies are found on the surface of B cells or are secreted. They are neither CD4 nor CD8 cells.

Answer for question no 5 : Option (E) - Resting

Explanation :

Resting membrane is the difference of voltage or charge between exterior of the cell and interior of the cell when the neuron is at rest. The net charge difference is negative relative to the exterior.

So, Option (E) is the right answer.

Option (A) is not the right answer as graded potentials occurs due to a stimulus and the ligand gated channels opens after that.

Option (B) is not the right answer as action potential is characterised by rise and fall of membrane potential accross the membrane following a pattern.

Option (C) is not the right answer as depolarization is a state where the membrane potential falls below the resting potential and makes the inside of the cell more negative.

Option (D) is not the right answer as a n action potential can't be generated during a specific period which known as refractory period. So, a refractory potential can't occur.