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Questions Related to zoology

Multiple choice zoology structure of chromosome, cell cycle and cell division structure of dna nucleic acid heredity and inheritance

The genetic information in the body is encoded in the

  1. Structural proteins

  2. Enzymes

  3. DNA

  4. DNA and enzymes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Deoxyribose Nucleic Acid or DNA carries the genetic information in the form of small segments known as genes and is also the genetic material in various organisms including humans.

Structural proteins and enzymes are the gene products that are synthesised from DNA through the process of translation.
Hence, the correct answer is 'DNA'.

Multiple choice zoology structure of chromosome, cell cycle and cell division structure of dna nucleic acid heredity and inheritance

Information from X-ray crystallographic data collected by was used by Watson and Crick in their development of the model of DNA.

  1. Chargaff

  2. Griffith

  3. Franklin

  4. Hershey and Chase
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Although the discovery of the structure of DNA was attributed to Watson and Crick, a keynote player in helping them discover this structure was a scientist by the name of Rosalind Franklin. Rosalind Franklin, along with Francis Wilkins, worked on DNA applying X-ray crystallography to find out its structural properties. X-ray crystallography required the process of exposing a crystal specimen (DNA) to X-rays to determine the locations of the atoms in the “molecules that comprises basic unit of crystal called unit cell”. 

So, the correct option is 'Franklin'.

Multiple choice zoology structure of chromosome, cell cycle and cell division structure of dna nucleic acid heredity and inheritance

Which of the following general statement about the structure of DNA is true?

  1. The hydrogen bonds connecting base pairs exist in a polar environment.

  2. Both major and minor grooves are formed between the phosphate-sugar backbone.

  3. The same C and N atoms are present in each groove.

  4. The amount of energy required to break down the AT and GC pairs is the same.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The DNA double helical structure has two different environments. The nitrogenous bases have an aromatic ring structure and are hydrophobic and interact with each other through base pair stacking interactions. At the same time, the back bone of DNA formed by phosphodiester bonds is hydrophilic and interacts with water. The nitrogenous bases of one nucleotide chain form hydrogen bonds with the nitrogenous bases present directly opposite them on the other chain. The hydrogen bonds are formed in polar aqueous environment. The adenine base pairs with thymine with two hydrogen bonds and guanine base pairs with cytosine with three hydrogen bonds.
So, the correct answer is option A.

Multiple choice zoology structure of chromosome, cell cycle and cell division structure of dna nucleic acid heredity and inheritance

If there are 10,000 base pairs in DNA, then its length

  1. 340 nm

  2. 3400 nm

  3. 34000 nm

  4. 340000 nm
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

According to the most widely accepted model of DNA structure, the distance between any two base pairs in DNA is approximately 3.4 angstroms. Thus for a DNA molecule having 10,000 base pairs; the length will be 10,000 x 3.4 or 34000 angstroms or 3400 nanometers.
So, the correct answer is option B.

Multiple choice zoology structure of chromosome, cell cycle and cell division structure of dna nucleic acid heredity and inheritance

In a DNA sample the proportion of A is 17%, the amount of G + T and C will be respectively.

  1. 50% and 33%

  2. 66% and 17%

  3. 66% and 33%

  4. 33% and 50%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In any double stranded DNA, adenine (A) pairs with a thymine (T) and Guanine (G) pairs with a cytosine (C).
Now, since each A always pairs with a T, the percentage of A and T will always be the same. Therefore, percentage of T will also be 17%.
So we can conclude that A+T=17+17=34%
The rest would account for G+C which would be 100-34=66%, thus G+C=66%.

Now, since each G always pairs with a C, thus the individual proportions of G and C will be 33%. 
So we get the base composition of DNA as A=T=17% and G=C=33%
Therefore, G+T=33+17=50% and C=33%.
Hence the correct answer is '50% and 33%'.

Multiple choice zoology structure of chromosome, cell cycle and cell division structure of dna nucleic acid heredity and inheritance

The eukaryotic chromosome contains nucleosome spools.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A nucleosome is a basic unit of DNA packaging in eukaryotes, consisting of a segment of a DNA wound in sequence around eight histone protein octamer cores. This structure is often compared to thread wrapped around a spool. Nucleosome constitutes the repeating unit of a structure in nucleus called chromatin, thread-like stained (colored) seen in the nucleus. The negatively charged DNA is wrapped around the positively charged histone octamer to form a structure called DNA helix.
So, the statement is 'True'.
Multiple choice zoology structure of chromosome, cell cycle and cell division structure of dna nucleic acid heredity and inheritance

How many amino acids will be coded by the given sequence of ribonucleotides, if the 15$^{th}$ base is substituted by G?
'5AUGGUGUAGAGGUACCAU3'

  1. Four

  2. Five

  3. Six

  4. Two
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Amino acid synthesis stops when any STOP codon is encountered by ribosome. There are total 3 stop codons, UAG, UGA, UAA. Codons are always read in triplets. So the given ribonucleotide sequence will be read as: AUG,GUG, UAG, and so on. Notice that the third codon (UAG) is a stop codon, so the protein synthesis will stop at the third codon itself. It doesn't matter if the 15th base is substituted by G or not, the given sequence will code for only two amino acids, AUG (methionine) and GUG (Methionine)

So, the correct answer is 'Two'.

Multiple choice zoology structure of chromosome, cell cycle and cell division structure of dna nucleic acid heredity and inheritance

DNA cannot pass through a cell membrane as

  1. It is too big to cross the membrane

  2. It is a hydrophilic molecule

  3. Membrane does not have specific proteins to facilitate the transport

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

DNA cannot pass through a cell membrane as it is hydrophilic in nature whereas cell membrane is made up of lipid bilayer. 

So, the correct option is 'Option B' .

Multiple choice zoology structure of chromosome, cell cycle and cell division structure of dna nucleic acid heredity and inheritance

Feulgen test, is unique for DNA, is a

  1. Gentian violet

  2. Neutral red

  3. Basic fuchsin

  4. Cotton blue
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The feulgen test is a staining technique discovered by Robert Feulgen and used in histology to identify chromosomal material or DNA in cell specimens.
  • The Feulgen test, is unique for DNA, is a Basic Fuchsin.
  • It is used for demonstration of DNA (deoxyribonucleic acid) in tissue sections. 
  • So, the correct answer is 'Basic fuchsin',