Whittaker classified organisms into five kingdoms. Of these the last kingdom is divided into two groups, invertebrates and vertebrates. Answer the following questions about this group:
Animals of which phylum give birth to young ones? Mention two more characteristic features of this phylum.

Whittaker classified organisms into five kingdoms. Of these the last kingdom is divided into two groups, invertebrates and vertebrates. Answer the following questions about this group: Animals of which phylum have a soft unsegmented body that can be divided into three parts? Name the three parts of their body.

Whittaker classified organisms into five kingdoms. Of these the last kingdom is divided into two groups, invertebrates and vertebrates. Answer the following questions about this group: Which phylum comprises animals that may exist in either of two forms: one that is attached to the ocean floor and the other that is free-floating? Mention one more characteristic feature of this phylum.

Name the phyla into which invertebrates are divided. Give two characteristics and two examples of organisms belonging to each phylum.

A candidate is required to answer 7. questions out of 12 questions which are divided into two groups each containing 6 questions. He is not permitted to attempt more than 5 questions from each group. The number of ways in which he can choose the 7 questions is

A candidate is required to answer 7 questions out of 12 questions, which are divided into two groups, each containing 6 questions. He is not permitted to attempt more than 5 questions from either group. Find the number of different ways of doing questions.

Seeing the growing cases of diabetes and depression among young children, Mr. Chopra, the principal of one reputed school organized a seminar in which he invited parents and principals. They all resolved this issue by strictly banning junk food in schools and introducing healthy snacks and drinks like soup, lassi, milk, etc. in school canteens. They also decided to make compulsory half an hour of daily physical activities for the students in the morning assembly. After six months, Mr. Chopra conducted the health survey in most of the schools and discovered a tremendous improvement in the health of the students. After reading the above passage, answer the following questions : (i) What are the values (at least two) displayed by Mr. Chopra ? (ii) As a student, how can you spread awareness about this issue ? (iii) Why should antidepressant drugs not be taken without consulting a doctor ? (iv) Give two examples of artificial sweeteners.

Given below are two stages in the evolution of man. Study them and answer the questions that follow : (i) Identify Australopithecus and Neanderthal man from the above pictures. (ii) Mention two characteristic features each for the two stages. (iii) Who proposed the theory of Natural Selection? (iv) Name the organism used as an example to explain 'Industrial Melanisum'. (v) Give two examples of Vestigial organs in humans.

A candidate is required to answer 6 out of 10 questions, which are divide into two groups, each containing 5 questions. He is not permitted to attempt more than 4 questions from either group. The number of different ways in which the candidate can choose 6 questions is a. 50 b. 150 c. 200 d. 250

It is not possible to measure the atomic radius precisely since the electron cloud surrounding the atom does not have a sharp boundary. One practical approach to estimate the size of an atom of a non-metallic element is to measure the distance between two atoms when they are bound together by a single bond in a covalent molecule and then dividing by two. For metals we define the term "metallic radius" which is taken as half the inter nuclear distance separating the metal cores in the metallic crystal. Then van der waal's radius represents the over all size of the atoms which includes its valence shell in a non bonded situation. It is the half of the distance between two similar atoms in separate molecules in a solid. The atomic radius decreases across a period and increases down the group. Same trends are observed in case of ionic radius. Ionic radius of the species having same number of electrons depends on the number of protons in their nuclei. Sometimes, atomic and ionic radii give unexpected trends due to poor shielding of nuclear charge by d -and f- orbital electrons. Now answer the following three questions: Which of the following relations is correct, if considered for the same element.

It is not possible to measure the atomic radius precisely since the electron cloud surrounding the atom does not have a sharp boundary. One practical approach to estimate the size of an atom of a non-metallic element is to measure the distance between two atoms when they are bound together by a single bond in a covalent molecule and then dividing by two. For metals we define the term "metallic radius" which is taken as half the inter nuclear distance separating the metal cores in the metallic crystal. Then van der waal's radius represents the over all size of the atoms which includes its valence shell in a non bonded situation. It is the half of the distance between two similar atoms in separate molecules in a solid. The atomic radius decreases across a period and increases down the group. Same trends are observed in case of ionic radius. Ionic radius of the species having same number of electrons depends on the number of protons in their nuclei. Sometimes, atomic and ionic radii give unexpected trends due to poor shielding of nuclear charge by d -and f- orbital electrons. Now answer the following three questions: K^(+), CI^(-), Ca^(2+), S^(2-) ions are isoelectronic. The decreasing order of their size is: