Name the stage of cell cycle at which one of the following events occur:
(i) Chromosomes are moved to spindle equator
(ii) Centromere splits and chromatids separate
(iii) Pairing between homologous chromosomes takes place
(iv) Crossing over between homologous chromosomes takes place

Crossing over is the exchange of genetic material between ______chromatids of homologous chromosomes.

Analyse the events during every stage of cell cycle and notice how the following two parameters change (i) number of chromosomes (N) per cell (ii) amount of DNA content (C) per cell

In which stage of meiosis, homologous chromosomes separate while sister chromatids remains assocaited at their centromeres-

Analyse the events during every stage of cell cycle and notice how the following two parameters change (i) Number of chromosomes (N) per cell (ii) Amount of DNA content (C) per cell Answer

Answer the following questions regarding the events carried out in the labelled parts of the ab ove given diagram. (1) DNA synthesis occurs in (2) Condenstaion of chromosomal material takes place in (3) Attachement of spindle fibres to kinetochores of chromosomes during (4) Initiation of the assembly of mitotic spindle during (5). Splitting of centromere and separation of chromatids in (6) Movement of chromatids to opposite poles during (7) Reformation of nucleolus, Golgi complex and ER occurs in (8) Alignment of chromosomes along metaphase plate during (9) During of cytoplasm during (10) Preparation of cell division takes place during.

Which one of the following statements is incorrect? (A) In cockroaches and prawns excretion of waste material occurs through malpighian tubules. (B) In ctenophores, locomotion is mediated by comb plates. (C) In Fasciola flame cells take part in excretion (D) Earthworms are hermaphrodites and yet cross fertilization take place among them.

Which of the following statement is true for variation in organisms? (1) The occurrence of differences among the individuals of the same species is known as variation. (2) Variations decrease the possibilities of survival. (3) The process of evolution decreases the variation in organisms. ( 4) During meiosis, crossing over takes place between the genes and hence, new combinations are formed, which ultimately results in producing variations.

Scientists are working hard to develop nuclear fusion reactor Nuclei of heavy hydrogen, _(1)^(2)H , known as deuteron and denoted by D , can be thought of as a candidate for fusion rector . The D-D reaction is _(1)^(2) H + _(1)^(2) H rarr _(2)^(1) He + n+ energy. In the core of fusion reactor, a gas of heavy hydrogen of _(1)^(2) H is fully ionized into deuteron nuclei and electrons. This collection of _1^2H nuclei and electrons is known as plasma . The nuclei move randomly in the reactor core and occasionally come close enough for nuclear fusion to take place. Usually , the temperature in the reactor core are too high and no material will can be used to confine the to plasma for a time t_(0) before the particles fly away from the core. If n is the density (number volume ) of deuterons , the product nt_(0) is called Lawson number. In one of the criteria , a reactor is termed successful if Lawson number is greater then 5 xx 10^(14) s//cm^(2) it may be helpfull to use the following boltzmann constant lambda = 8.6 xx 10^(-5)eV//k, (e^(2))/(4 pi s_(0)) = 1.44 xx 10^(-9) eVm Assume that two deuteron nuclei in the core of fusion reactor at temperature energy T are moving toward each other, each with kinectic energy 1.5 kT , when the seperation between them is large enough to neglect coulomb potential energy . Also neglate any interaction from other particle in the core . The minimum temperature T required for them to reach a separation of 4 xx 10^(-15) m is in the range

Scientists are working hard to develop nuclear fusion reactor Nuclei of heavy hydrogen, _(1)^(2)H , known as deuteron and denoted by D , can be thought of as a candidate for fusion rector . The D-D reaction is _(1)^(2) H + _(1)^(2) H rarr _(2)^(1) He + n+ energy. In the core of fusion reactor, a gas of heavy hydrogen of _(1)^(2) H is fully ionized into deuteron nuclei and electrons. This collection of _1^2H nuclei and electrons is known as plasma . The nuclei move randomly in the reactor core and occasionally come close enough for nuclear fusion to take place. Usually , the temperature in the reactor core are too high and no material will can be used to confine the to plasma for a time t_(0) before the particles fly away from the core. If n is the density (number volume ) of deuterons , the product nt_(0) is called Lawson number. In one of the criteria , a reactor is termed successful if Lawson number is greater then 5 xx 10^(14) s//cm^(2) it may be helpfull to use the following boltzmann constant lambda = 8.6 xx 10^(-5)eV//k, (e^(2))/(4 pi s_(0)) = 1.44 xx 10^(-9) eVm Assume that two deuteron nuclei in the core of fusion reactor at temperature energy T are moving toward each other, each with kinectic energy 1.5 kT , when the seperation between them is large enough to neglect coulomb potential energy . Also neglate any interaction from other particle in the core . The minimum temperature T required for them to reach a separation of 4 xx 10^(-15) m is in the range

Air distance between Kota to Jaipur is 260 km and road distance is 320 km. A deluxe bus which moves from Jaipur to Kota takes 8 h while and aeroplane reaches in just 15 min. Find (i) average speed of bus in km/h (ii) average velocity of bus in km/h (iii) average speed of aeroplane in km/h (iv) average velocity of aeroplane in km/h