The circulatory system has evolved from open to closed type in Animal Kingdom. Which phylum can be called first to represents closed circulation?

The cirulatory system has evovled from open to closed type in Animal Kingdom. Which Phylum can be called first to represent closed circulation.

Which of the following animals do not have closed circulation?

Fill in the blanks by selecting the correct word from the bracket and complete the given paragraph. (two, Ramapithecus, modern sciences, seven, Neanderthal man, lemurs, agriculture, organgutans) The lase dinosaurs disappeard apprximately ____________ crore years ago. Monkey -like animals are said to have evolved from some ancestors who were similar to modern______________. The first human like animals with erect posture evolved about_________ crore years ago. The first record of this human like ape is __________ from East Africa. ______________ can be considered as the first member of the class-wise man. About 10 thousand years ago, wise -man started to practice.

Differentiate between: Open circulatory system and closed circulatory system.

Read the paragraph and answer the questions given below : Locomotion is considered as an important characteristics of the animals. However, animals belonging to Porifera are said to be sedentary. Every other phylum has typical locomotory organs. E.g. Nereis crawls with the help of parapodia, whereas earthworm buries in soil by setae. Spiders have four pairs of walking legs, crab has five while all insects have three pairs of walking legs. The walking legs are also called appendages. Starfish moves with the help of tube feet. Snails and bivalves use muscular foot for locomotion. Birds flying with their spread out wings and fish swimming with their fins, both have spindle-shaped body tapering at both the ends. While flying or swimming such body offers least resistance during locomotion. Mammals have two pairs of limbs while animals like snakes are limbless. Other animals belonging to the class of snakes also have very weak limbs.which make them creep on the ground. Answer the question: Which phylum has a characteristic of jointed appendages?

A pipe open at both the ends has a fundamental frequency of 600 Hz . The first overtone of a pipe closed at one end has the same frequency as the first overtone of the open pipe. How long are the two pipes ?

Answer the following Read the paragraph and answer the questions given below it. A biotic carbon atoms are circulated into the biotic form through processes like photosynthesis and respiration. Green plants convert carbon dioxide into carbohydrates and also produce carbon compounds like proteins and fats. Biotic compounds are transported from plants to apex consumers through intermediate trophic levels. After the death of all types of consumers, carbon is recycled by biotic decomposition. The carbon recycled in this way goes into the atmosphere and can be taken up by living organisms thus ensuring circulation and recycling of carbon in the biosphere. By which process do green plants convert atmospheric carbon into carbohydrates?

Answer the following Read the paragraph and answer the questions given below it. A biotic carbon atoms are circulated into the biotic form through processes like photosynthesis and respiration. Green plants convert carbon dioxide into carbohydrates and also produce carbon compounds like proteins and fats. Biotic compounds are transported from plants to apex consumers through intermediate trophic levels. After the death of all types of consumers, carbon is recycled by biotic decomposition. The carbon recycled in this way goes into the atmosphere and can be taken up by living organisms thus ensuring circulation and recycling of carbon in the biosphere. Which bio-geo-chemical cycle is described in the given paragraph?

Read the following paragraph and answer the following questions given below it : Construction of a compound microscope : (i) Acompound microscope consists of a metal tube fitted with two convex lenses at the two ends. These lenses are called the objective lens ( the lens directed towards the object ) and the eyepiece ( the lens directed towards the eye ). Both the lenses are small in size , but the cross section of the objective lens has a short focal length . the focal length of the eyepiece is more than that of the objective lens . (ii) The metal tube is mounted on a stand . thr principal axes of the objective lens and the eyepiece are along the same line . The distance between the object and objective lens can be changed with a screw . It is possible to change the distance between the objective lens and the eyepiece. Working : (i) The object to be observed is illuminated and placed in front of the objective lens. slightly beyond the focal length of the objective lens. it's real , inverted and enlarged image is formed by the objective lens on the other side. (ii) This intermediate image lies with in the focal length of the eyepiece. It serves as an object for the eyepiece. The eyepiece works as a simple microscope . the final image is virtual, highly enlarged and inverted with respect to the original object . It can be formed at the minimum distance of distinct vision from the eyepiece . The final image is observed by keeping the eye close to the eyepiece. Use: This microscope is used to observe blood cells , microorganisms , etc. In a compound microscope , which lens has greater focal length ?