How does binary fission differ from multiple fission?
Asexual reproduction occurs in different ways in different organisms. So, binary fission and multiple fission both are the types of asexual reproduction.
Binary fission:- It is the division of parent cell into two small daughter nucelii. Mainly three types of binary fission shown in some organisms- Irregular, longitudinal, transverse. Like in protozoan protists, the replicated chromosome separated by intranuclear mitosis and starts dividing. Then, the cytoplasm constricts between two separating nuclei and forms two equal sized daughter nuclei with a nucleus (eg. Amoeba shows irregular fission, Euglena shows longitudinal fission and Paramecium shows transverse binary fission). Or like in Planarians also, they are divided by transverse binary fission with the equal sized daughter individuals.
Multiple fission:- Unlike binary fission, the division of parent cell will be into many small daughter nuclei. And it can be shown in mainly two organisms- Plasmodium or Amoeba. Plasmodium is a malarial parasite, when multiple fission takes place in adults or in its encysted zygote (called sporogony) and their daughter individuals are then called merozoites.
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
Outline a project which aims to find the dominant coat colour in dogs.
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?
How is the sex of the child determined in human beings?
(a) What property do all elements in the same column of the Periodic Table as boron have in common?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common?
Calculate the number of electrons constituting one coulomb of charge.
What is an homologous series? Explain with an example.
Why is variation beneficial to the species but not necessarily for the individual?
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
How would you distinguish experimentally between an alcohol and a carboxylic acid?
Butanone is a four-carbon compound with the functional group
(a) carboxylic acid.
(b) aldehyde.
(c) ketone.
(d) alcohol.
Why do ionic compounds have high melting points?
A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is
(a) towards south (b) towards east
(c) downward (d) upward
Do basic solutions also have H+(aq) ions? If yes, then why are these basic?
The human eye forms the image of an object at its
(a) cornea. (b) iris. (c) pupil. (d) retina.
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
State the principle of an electric generator.
People use a variety of methods to wash clothes. Usually after adding the soap, they ‘beat’ the clothes on a stone, or beat it with a paddle, scrub with a brush or the mixture is agitated in a washing machine. Why is agitation necessary to get clean clothes?
Give an example of a metal which
(i) is a liquid at room temperature.
(ii) can be easily cut with a knife.
(iii) is the best conductor of heat.
(iv) is a poor conductor of heat.