12th Class Biology Chapter 6

“Learn about chromosomes and DNA, exploring their structure, function, and crucial role in heredity and genetic information transmission.”

Chapter 6 Biology Class 12 MCQs

The Syndrome which is an example of trisomy of the sex chromosome is: Klinefelter’s syndrome

In incubating eggs artificially the incubators are usually regulated at temperature between: 36 – 38oC

For maximum growth the optimum temperature is 25 – 30oC and it least at: 5 – 10oC

From Hensen’s node,dorsal mesoderm is formed and is organized into: Somitcs

On the basis of structure and shape of the cap,two species of Acetabularia have been identified: A.crenulata & A.arabica

In addition to auxin which hormone also play important role in apical domince: Cytokinins

in plants regeneration is the basis of plant: Reptiles

Primary tissue is added by the: Apical meristem

Which one of the following condition is resulted from excess GH in adults: Acromegaly

If lobster loses its pincer claw a new claw: Regenerates

Deficiency of vasopressin or ADH by the pituitary gland leads to a disorder in which the patients kidney have lessoned ability to absorb water is: Diabetes insipidus

An ordered sequence of irrversible steps with each step setting up the necessary conditions for the next step is: Development

Which of the following hormones is not released by the anterior pituitary: Melanocyte – releasing hormone

Which prosess is characterized by movement and rearrangement of cells in the embryo: Gastrulation

In the chick the mesodermal cells migrate and caudally from both sides and create a mid line thickening called: Primitive streak

Parathyroid hormone acts to ensure that: Calcium levels in the blood never drop too low

In humans ,MSH(melanocyte-stimulating hormone): Regulates primary skin color

During elongation the cell volume increase up to 150 fold due to uptake of: Water

A plant has a growth pattern called: Open growth

The negative physiological changes in our body are said to be: Agning

Clear cytoplasm produces: Larval epidermis

In chordates the healing of fracture and repair of a skin wound are some other examples of: Regeneration

_______ regulates the kidney’s retention of water: Vasopressin (ADN)

Oxytocin is secreted by the endocrine gland named: Pituitary gland

The addrenaline cortex produces: Aldosterone

The genetic code for glycine is: GGU

The stand which elongates towards the replication fork is: Leading

Morphological characteristics of chromosome are collectively called: Karyotype

In 1953, F . Sanger described the sequence of amino acids of: Insulin

Repeating units of DNA are called: Nucleotides

In sickle cell anemia code for glutamic acid is replaced by: Leucine

DNA was discovered in: 1869

Every 200 nucleotides the DNA duplex is coiled around a core of eight histone proteins forming a complex known as a: Nucleosome

Adenine and guanine are called: Purines

Walter Fleming first discovered chromosomes in the dividing cells of: Salamander larvae

Important : Review all previous years’ 12 class past papers for comprehensive practice and better exam preparation.

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