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devices which are used as birth control devices. The copper ions released reduces sperm motility and its fertilising capacity. The hormones released makes the uterus unstable for implantation and the cervix hostile to the sperms.

(c) Klinefelter^ syndrome is a genetic disorder which occurs due to trisomy of sex chromosome which shows gynaecomastia like character and its karyotype is 44 + XXY i.e., individual has 47 chromosome. (d) Colostrum is the first secretion from the breast

occurring shortly after or sometimes before birth prior to the secretion of true milk. This is yellowish fluid that contains cells from the alveoli and are rich in protein and low in fat. It is rich in antibodies (Ig A is the major immunoglobulin) and provides passive immunity to the new born infant.

(e) The sequence of accessory ducts in human testis after seminiferous tubules is rete testis vas efferentia —> caput epididymis —» cauda epididymis vas deferens - » urethra.

17. (a) Kangaroo rat may live whole life without water, urea is the main excretory product.

(b) Diesel automobile S02, suspended particulate

matter

(c) Methemoglobinaemia excess nitrates in water, can be fatal to infant

(d) Endangered species —> wolf, wild ass, Red panda, Great Indian bustard

(e) Ozone hole —> CFC

18. (a) There are various factors by which normal cells differ from cancer cells.

Cancer cells Normal cells (1) They do not undergo

differentiation.

(1) They undergo differ- entiation.

(2) The cells do not require extracellular growth factors.

(2) The cells require ex- tracellular ' growth factors.

(3) Cells do not remain adhered.

(3) Cells remain adhered to one another. (4) Cancer cells undergo

uncontrolled divisions.

(4) Cell divisions are regulated.

(5) Cell death is inhibited. (5) Normal cells have fi- nite life span. (6) They tend to form tu-

mours.

(6) Tumours are not formed.

( 7 ) They pass out of tu-

mours to reach new sites (metastasis)

( 7 ) There is no passage

from one site to an- other.

( 8 ) Nucleus is irregular,

hypertrophied and granular.

(8) Nucleus 1s rounded

or oval with normal chromatin reticulum.

( 9 ) The cells are rich in

melanin, mucus, fat drops and lysosomes.

( 9 ) They have a normal

number or amount of these substances. ( 1 0 ) Mitochondral cristae are fewer. (10) Mitochondrial cristae are normal.

(11) Cellular gene is onco-

gene (11) Cellular gene is pro-to-oncogene. (b) The correct carcinogens are asbestos, gamma rays,

tobacco smoke, and arsenic.

(c) Detection and diagnosis of cancer depends upon his- tological features of malignant structure.

(I) Biopsy of bone marrow and abnormal count of WBCs is done in case of leukemia.

(ii) Pap test (cytological staining) is used for detecting cancer of cervix and other parts of genital tract. (iii) Techniques such as radiography, CT scan (computed

tomography), MRI scan (magnetic resonance imaging) are very useful to detect cancers of the internal organs. 19. (a) The stages A, B, C, and D are multiplication stage,

growth stage, maturation stage and spermiogenesis stage and the cells are spermatogonia, primary sper- matocyte, secondary spermatocyte and spermatids. (b) The numerical valve of E, F and G are 46, 23 and 23

respectively.

(c) The structure represented by R and S are primary oo- cyte and secondary occyte.

(d) M and N are first polar body and second polar body. M and N are smaller than S and ovum because first and second meiotic division results in unequal hap- loid daughter cells i.e., unequal cytokinesis occurs. The resulting polar bodies have small amount of cytoplasm which helps to retain sufficient amount of cytoplasm in the ovum which is essential for the development of early embryo and also formation of polar bodies maintains half number of chromosomes in the ovum.

20. (a) Monera (b) Dinucleotide (d) Uridine (f) Leydig cells (h) Animal (j) Allosteric enzyme (a) Monera (c) Triacylglycerides (e) SER (g) Passive (i) Glycoprotein

emus

STB5

O All students preparing for PMT examinations can participate in V H B i o - G e n i u s Contest. O Answers marked only on the entry form of the magazine / photocopy of form will be accepted. O More than one response to a question will be disqualified.

Prizes

. 1 st Prize - LG Mobile phone • 2nd Prize - Adidas Bag • 3rd Prize - MTG Books (worth Rs. 500/-) O The entries with maximum number of correct answers for three consecutive months (Aug '08 - Oct '08) will be awarded

1st prize. 2nd and 3rd prize will be given to the next maximum scorers. In case of a tie, the winners will be decided through a lucky draw.

O The decision of the editor will be final and binding in all cases and will not be a matter for consideration of any court and no correspondence will be entertained.

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O Last Date: The entries should reach on/before 31s1 August '08 to -

WfcfcG" Bio-Genius Contest, 406, Taj Apartment, Ring Road, Near Safdarjung Hospital, New Delhl-29. Which of the following statements is incorrect?

(a) endospores are highly resistant bodies produced within the cells of certain gram positive bacteria only. (b) the process of endospore formation is known as sporulation and it results into only one endospore formation from a single bacterium.

(c) besides being a mean to tide the unfavourable condi- tions they also help the bacteria in reproduction. (d) the high resistance of the endospores is attributed

to dipicolinic acid present in the endospores which is not found in the vegetative cells of bacteria. Match column I and column II and select the correct answer using the codes given below

Column I (1) Oyster mushroom (2) White button mushroom (3) Entomogenous fungi (4) Patulin (1)

(2)

(a)

(E) Blakeslea trispora

3. Which of the family lacks betacyanin in their body? (a) chenopodiaceae (b) caryophyllaceae (c) cactaceae (d) aizoaceae 4. Pyrenoids are absent in the chloroplast of

(a) Chlamydomonas (b) Batrachospermum (c) Spirogyra (d) Polysiphonia 5. The genus Porphyra of rhodophyta is similar with which

of the following member of chlorophyceae? (a) Prasiola (b) Cutleria (c) Corallina (d) Gracilaria

6 Aspergillus niger is a fungus which is used to determine the availability of certain metals. They are

(a) magnesium (b) potassium (c) molybdenum (d) all of these

7. In which of the following bacteria the energy source & carbon source are usually the same organic compound? (a) photoheterotrophs (b) chemoorganotrophs (c) photoorganotrophs (d) chemolithotrophs. 8. Bacteria that fix CO, in a cycle involving organic acids

instead of using ribuiose biphosphate cycle are (a) mycoplasmas (b) L-forms

(c) methanogens (d) cyanobacteria

I