4exam

Question 1   ( 1.0 marks) A certain plant  ‘X’ shows the presence of vascular tissue, but does not produce seeds. To which division does plant ‘X’ belong? Solution: Pteridophytes Question 2   ( 1.0 marks) Fill in the blanks . Reptiles have __________-chambered heart, while fishes have __________-chambered heart. Solution: Reptiles have  three -chambered heart, while fishes have  two -chambered heart. Question 3   ( 1.0 marks) Give two examples of cartilaginous fishes. Solution: Scoliodon  and shark Question 4   ( 2.0 marks) Differentiate between bilateral symmetry and radial symmetry. Solution: - Radial Symmetry - Bilateral  Symmetry ( i) If the body of an animal is divided into two equal parts by cutting it in any plane passing through the centre of its body, then the body of the animal is said to have radial symmetry. (i) If the body of an animal is divided into left an...

Question 1   ( 1.0 marks) Carl Woese further subdivided kingdom monera into two categories. What are these? Solution: Eubacteria and archaebacteria Question 2   ( 1.0 marks) Name the group of plants that do not contain well-differentiated body components. Solution: Thallophyta (algae) Question 3   ( 1.0 marks) Which fundamental characteristic separates animals from plants? Solution: Locomotion is present in animals, and not in plants. Question 4   ( 2.0 marks) Draw a branch diagram to represent the five-kingdom classification. Solution: Question 5   ( 2.0 marks) Mention the main features of kingdom monera. Solution: Main features of kingdom monera: (i) Absence of a well-defined nucleus and membrane-bound organelles (ii) Absence of multicellular design; all of them are unicellular Question 6   ( 2.0 marks) State any two general features of division gymnospermae. Solu...

Question 1   ( 1.0 marks) Calculate the mass  (in grams) of the iron sulphide formed when 5.6 g of iron combines with 3.2 g of sulphur. (Atomic mass of Fe = 56 u and Atomic mass of S = 32 u) Solution: Fe + S → FeS 56 g of Fe + 32 g of S = 88 g of FeS ∴ 5.6 g of Fe + 3.2 g of S = 8.8 g of FeS Question 2   ( 1.0 marks) What is the mass of 0.5 mole of Cl 2  gas? Solution: The molecular mass of chlorine is 35.5  u. Mass = Molar mass × N umber of moles = 35.5 × 2 = 71 g Question 3   ( 1.0 marks) Define one mole of a substance. Solution: One mole of a substance is the quantity of the substance containing 6.022 × 10 23  molecules of particles. Question 4   ( 2.0 marks) Cal culate the molecular mass of Ca (OH) 2 . Solution: M olecular mass of Ca (OH)  2  = (1 × 40 + 2 × 16 + 2 × 1) g = (40 + 32 + 2) g = 74 g Question 5   ( 2.0 marks) What is the significance  of ...

Mass can neither be created nor destroyed in a chemical reaction. This is known as the law of conservation of mass. It means that the sum of the masses of the reactants and the products remains the same during a reaction. The law of constant proportion states that a chemical substance always contains the same elements in a fixed proportion by mass, irrespective of the source of compound. Matter is made up of very tiny particles and these particles are called atoms. Atoms cannot be divided further i.e., atoms are indivisible. An atom can be defined as the smallest particle of matter that can neither be created nor destroyed by chemical means. The symbol of the element is made from one or two letters of the English or the Latin name of the element. The mass of an atom is known as the atomic mass. The atomic mass of an atom of an element is also known as its relative atomic mass, since it is determined relative to the mass of C-12 isotope. A molecule is formed when two or ...

Grade 9 Why Do We Fall Ill Health  Health - A state of physical, mental, and social well-being, which includes a unity and harmony within the mind, body, and soul of an organism Diseases  Disease - Any condition that can lead to discomfort, distress, health problems, and even death of the affected person  Symptoms - Indications of disease, such as headache, stomach pain, nausea, etc.; can only be felt by the patient  Signs of a disease include fever, vomiting, diarrhoea, etc.; can be observed by a physician  Incubation period - The time interval between infection and appearance of symptoms Causes of diseases  On the basis of its duration - Acute and Chronic Acute - Lasts for a short period of time, eg. cold, cough, influenza, etc. Chronic - Lasts for long periods of time, eg. diabetes, kidney stones, etc.  On the basis of causative agents - Infectious and Non-infectious Infectious - Diseases such as influenza, cold, etc., which are caused due to infectious ...