Nseb

Find out the incorrect statement about action of hormones: 

(a) Steroid hormones are lipid soluble and pass across the cell membrane easily. 

(b) Synthesis of secondary messengers in the cell is activated by the binding of peptide hormones. 

(c) Receptor-steroid hormone complex binds to DNA causing transcription of genes. 

(d) Production of cAMP in the cell is activated by binding of steroid hormone to receptor.

A biochemist prepared a mixture of all reactants and enzymes he thought were needed for DNA replication. When DNA was added, replication occurred. The product, however, consisted of the parent DNA strand paired with several DNA segments, each segment, a few hundred nucleotides long. Which of the following could possibly be missing in the reaction mixture?

(a) DNA polymerase. 

(b) RNA primers. 

(c) DNA ligase. 

(d) Single strand binding proteins

The extracellular fluid in human body contains large amounts of sodium, chloride, bicarbonate ions and other nutrients for the cells. Which of the following can be categorized as extracellular fluid? 

i. Lymph 

ii. Renal interstitial fluid 

iii. Axoplasm 

iv. Cerebrospinal fluid 

(a) i, ii, iii and iv 

(b) i,& iii only 

(c) i, ii and iv only 

(d) i & ii only

The diagram below shows the concentration of hormones in circulating blood as percentage of their maximum possible concentration. Which phase of ovarian cycle of a mammal does it represent?

A littoral gastropod will have thickest shell when it is located at the 

(a) high tide marks on a rock beach. 

(b) greatest depth in a sand beach. 

(c) low tide marks on a mud beach. 

(d) bottom of a rock pool

The following pedigree traces the trait calIed achondroplasia, a form of dwarfism. Which of the following hypothesis can be supported by given pedigree?

(a) The trait is due to dominant allele. 

(b) The trait is due to recessive allele. 

(c) The trait is sex linked. 

(d) Given information is not sufficient to hypothesize the situation.

Some honey bee strains make a practice of removing the carcasses of dead larvae from their nests. This hygienic behaviour seems to be under the control of two recessive genes – uncapping the larval cells (U or u) and removing the carcass (R or r). Which of the following bees are non hygienic, but will remove dead pupae if cells are uncapped? 

(a) UuRr 

(b) uuRr 

(c) Uurr 

(d) uurr

In principle,longest Henle’s loop should be found in the nephrons of desert dwelling mammal feeding mainly on : 

(a) succulent cactus 

(b) fleshy fruits 

(c) leathery leaves 

(d) seeds

The extend of tilt in the earth’s rotation has no influence on : 

(a) patterns of global climate 

(b) different seasons 

(c) periods of glacial expansion/retreat. 

(d) atmospheric concentrations of gases.

In a experiment, a person was subjected to perform 90 minutes leg extension exercise once a day for five days. Every day only the left leg was exercised while other was kept at rest. on the fifth day, concentrations of different mRNAs were measured from muscles of both legs, towards the end of the exercise session. Three major types of mRNAs, P, Q and R were found to show distinct variations in levels:

The following are the possible genes from which these mRNAs are synthesised; 

I. Gene responsible to initiate cell division 

II. Stress response gene 

III. Mitochondrial protein synthesis gene 

IV. Metabolic priority gene P, Q and R respectively must be for mRNAs of 

(a) II, IV and III 

(b) I, II and IV 

(c) II, IV and I 

(d) IV, II and I