School & Entrance Prep

Observe the given sequence of nitrogenous bases on a DNA fragment:

$5^{\prime}\text{-C A G A A T T C T T A-}3^{\prime}$ $3^{\prime}\text{-G T C T T A A G A A T-}5^{\prime}$

Write the sequence after the restriction enzyme EcoRI cuts the palindrome.

The symptoms of malaria do not appear immediately after the entry of sporozoites into the human body when bitten by a female Anopheles mosquito. Explain why it happens.

Samples of blood and urine of a sportsperson are collected before any sports event for drug tests. Why is there a need to conduct such tests?

Draw a growth curve where resources are not limiting for the growth of a population and give its equation.

Draw a pyramid of number where a large population of insects feed upon a very big tree. The insects in turn, are eaten by small birds which in turn are fed upon by big birds.

Construct a pyramid of biomass starting with phytoplankton, label its three trophic levels. Is the pyramid upright or inverted? Justify your answer.

Abbreviations used for the different modes of assisted reproductive technology are given below. Expand the abbreviations: (i) ZIFT (ii) ICSI (iii) IUT (iv) GIFT

How does the process of Natural Selection affect Hardy-Weinberg equilibrium? Explain with the help of graphs.

The insulin synthesised in our body is different from that synthesised by Eli Lilly company using recombinant DNA technology. Differentiate between them.

Out of the two population growth curves, which one is considered more realistic for most populations? Why?

Differentiate between thalassemia and sickle cell anaemia on the basis of their effect on the globin molecule of Haemoglobin.

Write the names of two closely linked genes that control $\alpha$-thalassemia.

Observe the given sequence of nitrogenous bases on a DNA fragment:

$5^{\prime}\text{-C A G A A T T C T T A-}3^{\prime}$ $3^{\prime}\text{-G T C T T A A G A A T-}5^{\prime}$

Name the restriction enzyme which can recognise this DNA sequence.

Why are the ends generated after digestion by a restriction enzyme called 'Sticky Ends'?

A bilobed dithecous anther has 200 microspore mother cells per microsporangium. How many male gametophytes can be produced by this anther?

Write the composition of the intine and exine layers of a pollen grain.

Why is there a statutory ban on Amniocentesis? Give at least two reasons.

Using a Punnett square, work out the distribution of an autosomal phenotypic feature in the first filial generation after a cross between a homozygous female and a heterozygous male for a single locus.

Samples of blood and urine of a sportsperson are collected before any sports event for drug tests. Name the drugs the authorities usually look for.

Samples of blood and urine of a sportsperson are collected before any sports event for drug tests. Write the generic names of two plants from which commonly tested illicit drugs are obtained.

Why is the insulin extracted from an animal source not in use these days?

Draw a graph for a population whose population density has reached the carrying capacity.

Study the graph showing Ovarian Hormone levels. Specify the primary source of the hormones 'P' (Estrogen) and 'Q' (Progesterone) marked in the diagram.

Study the graph showing Ovarian Hormone levels during the menstrual cycle. Identify the hormones 'P' and 'Q' labelled in the diagram.

Study the graph showing Pituitary Hormone levels during the menstrual cycle. Identify the hormones 'P' and 'Q' labelled in the diagram.

Study the graph showing Pituitary Hormone levels. Write down the role of hormone 'P' (Luteinizing Hormone) in both males and females.

Describe any two situations where a medical doctor would recommend the injection of pre-formed antibodies (antitoxins) into the body of a patient.

Assertion (A): A patient of ADA-deficiency requires periodic or repeated infusion of genetically-engineered lymphocytes. Reason (R): Lymphocytes are not immortal, but have life span.

Select the correct option:

Identify the organism whose product has been commercialised as a blood cholesterol lowering agent.

During gel electrophoresis migration of DNA fragments leading to their separation takes place on the agarose gel. Choose the correct option: