9th 10th
Receptors In Man (10th-Biology-Lesson-15.3) part 3
Organ of hearing (ear) Hearing and balancing The ears contain receptor cells that are sensitive to sound vibrations between frequencies of 20 Hz to 25000 Hz (hertz). The exact range varies with age of a person. The human ear has the following divisions. Out ear Middle ear Inner ear Outer ear It consists of an [...]
Receptors In Man (10th – Biology – Lesson – 15.3) part 2
The third and the inner most layer of eye is the retina. It is the sensitive layer of the eye. It is supplied by branches of optic nerve which enters the eye ball from brain. The sensory cells of retina are of two types: Rods 2. Cones These cells help in the formation of image [...]
Receptors In Man (10th-Biology-Lesson-15.3) part 1
15.3 Receptors in man Receptors are the sensory organs which receives a stimulus. Following are the main receptor organs in man. Organ of sight (eyes) Organ of hearing (eyes) Organ of smell (nose) Organs of taste (taste buds on tongue) Organ of touch (skin) Sight Eyes are the most marvelous of the sense [...]
Support And Movement In Man – Key Points (Biology-Lesson-14.6)
Support in man; woody and non-woody parts of plant is due to skeleton; various mechanical tissues and presence of water in their parenchymatous cells besides cylindrical distribution of conducting tissues respectively. Movement is response shown by a part of living organism towards or away from the stimulus while locomotion refers to the movement of whole [...]
Refraction Through A Prism (10th-Physics-Lesson-14. 9)
Prism is a transparent body having three rectangular and two triangular surfaces as shown in fig. 14. 9 (a). The angle of the triangular surface opposite to its base is known as “Angle of prism”. Fig. 14.9 (b) shows the path of a ray of light refracted through a prism. The incident ray PQ strikes [...]
Support And Movement In Man (Biology-Lesson-14.6) Part 4
14.6.7 Defects of skeleton system (a) Changes in bones Bones become thinner, weaker and less flexible with aging. This is partly because required calcium level starts decreasing at the age of 34 years. This happens to every-body to some extent. In some people it is particularly serious. In such cases it results in a condition [...]
Support And Movement In Man (Biology-Lesson-14.6) Part 3
14.6.5 functions of tendons and ligaments in relation to movement Many of the muscles that extend your toes are actually in your lower leg. The tendons from these muscles travel over the front of your ankle, across the upper surface of the foot bones, and attach to the bones of our toes. Straps of ligaments [...]
Support And Movement In Man (Biology-Lesson-14.6) Part 2
14.6.3 Action of flexors and extensors as a pair of opposing muscles. Fig. 14.19 action of antagonistic sets of muscles at elbow Muscles are attached to the bones at two points. One end of a set of muscles is usually attached to an immovable and rigid bone while that of the other is attached to [...]
Support And Movement In Man (Biology-Lesson-14.6) Part 1
In higher animals, including man, the skeleton provides support, protection and helps in movement. Support and movement in man is carried out with the help of skeleton and muscles. Skeleton is a hard framework of human body consisting of 206 bones of various shapes and sizes; long and short; flat or irregular. Skin and muscles [...]
Simple Past or Past Indefinite Tense Page 1
Simple Past or Past indefinite Tense OR Preterits. فعل ماضی مطلق اس ٹینس کو بنانے کیلئے چند سادہ سی باتیں یاد کرلیں۔ تمام مثبت فقروں میں verbکی دوسری حالت استعمال کریں۔ Examples: He went home, She borke the window. They wept last night. (2)اس ٹینس میں helping verbsاستعمال نہیں ہوتے ہیں ہاں wasاورwereکو بطورmainverbsاستعمال [...]
