1. what stops blood from flowing backwards through the heart.
2. platelets help in clotting of blood and injured side draw a flowchart of this process.
3. Explain how deoxygenated blood travel from body to learn for purification draw well labelled diagram in support of your answer.
4. When the right Atrium contracts blood flows from it to which part of the heart.
5 . write a common feature between the following
1 xylem and phloem
2 haemoglobin and chlorophyll
6. blood does not clot in blood vessels give reason
7. Tabulate two differences between renal artery and renal vein
8 where is the urine produced by the Kidneys gets stored
9 what are the major constituents of urine.
10 how do plants get rid of their excretory products.
11 explain how the blood system carries waste product from liver to the Kidneys
12. Is reflex action the only function of spinal cord support your answer with a single statement
13 how is geotropism necessary for plant
14 name the source organ and target organ of adrenaline
15 neuron is the longest cell but it does not undergo reproduction why is it so
16 give the flowchart of the nervous system of the human beings
17 midbrain connector for brain and hindbrain write its role in CNS
18 trapezium is directional whereas Nastic Movement is non directional justify this statement
19 pancreas is the overall controller of the blood glucose level give your views
20 a plant in the laboratory is given increase dose of a hormone which promotes the development of seedless fruits identify the hormone and write its other two functions
21 write any three endocrine glands and chemical produced by them
22 for what position of an object a concave mirror forms a real image equal in size to the object
23 a dentist uses a mirror in front of a decayed tooth at a distance of 4 cm from the tooth to get a 4 times magnified image in the mirror use mirror formula to find the focal length and nature of the mirror used
24 array of light strikes the glass slab at the angle of 90° what is the angle of incidence and the angle of refraction
25 when two or more lenses are placed in contact what will be their combined power
26 a ray of light incident on the one face of a rectangular slab emerges from the opposite face of the slab parallel to the direction of the incident ray why does it happened so
27 a ray passing through the centre of curvature of a spherical mirror after reflection returns along the same path why
28 why does a Ray of light band from its path when it travels from one medium to another
29 array of light travelling from a medium X enters obliquely into another medium Y if it went away from the normal then state which one of the two is relatively optically denser why
30 why is the refractive index of atmosphere different at different altitudes
31 the radius of curvature of a concave mirror is 50 cm where should an object be placed from the mirror so as to form its image at Infinity justify your answer
32 name the condition resulting to the eye lens becoming cloudy
33 why is normal I not able to see clearly the objects kept closer than 25 CM explain in brief
34 how does the thickness of the eye lens change when we shift looking from a distant tree to reading a book
35 no Rainbow could be observed from the surface of moon by the astronauts what could be the possible reasons
36 when a light ray passes obliquely through the atmosphere in an upward direction how does its path generally change
37 what is meant by near point and fire point of an eye state their values for the normal human eye
38 mention the position where images focused in the eye of a person having hypermetropia
39 state the role of ciliary muscles in accommodation
40 name the part of the eye wear images formed by the islands what is the nature of the image formed how is this image sent to the brain
41 derive the relation between kilowatt hour and joule
42 why is an alternating currents considered to be advantageous over direct current from long range transmission of electric energy
43 with the help of a diagram of experimental setup describe an activity to show that the force acting on a current carrying conductor placed in magnetic field increases with increase in field strength
44 name any two devices used to harness solar energy
Answers
Valves between the atrium and ventricle prevent the flow of blood backwards into the atria.
Platelets are normally the tiny blood cells helps body from clotting and stops bleeding.
Deoxygenated blood would travel from Right Atrium->Right Ventricle -> Pulmonary Artery-> Lungs for the purification.
Cataract is characterized condition by the eye lens and becomes cloudy.
Blood would enter into the heart through 2 large veins then superior and inferior vena cava thus emptying the oxygen-poor blood from body to right atrium.
1-valves
3-deoxygenated blood comes through veins from diff. Parts of the body into the right atrium.from here it goes to right ventricle and finally pumped to lungs through arteries for purification
4-right ventricle
5-1-they are the means of transportation in plants
5-2-they are the pigments of blood and green plants respectively.
8-urinary bladder
9-major constituents of urin are urea and uric acid.
10-through gums and resins...or through the removal of leaves..or they sometime release waste in soil
32-cataract
33- bcoz the eye is not capable of forming the image of object on the retina
35- no refraction
.........hope it will help uh..