M. C.

KEJRIWAL VIDYAPEETH
CLASS X SUBJECT : BIOLOGY LOCATION
AND FUNCTION
1. STRUCTURE LOCATION FUNCTION
2. Centrosome Region surrounding centrioles located Initiates and regulates cell division in the animal
near the nucleus. cell
3. Chromatin In the nucleoplasm in interphase Carry hereditary information in genes.

4. Vacuoles Clear spaces in cytoplasm with water or Give turgidity or shape or shape to the plant
substances in solution. cells by pressing against cell wall/ holds cell sap,
materials or wastes.
5. Thylakoid Stacks that form the grana of the Site of light dependent reaction.
chloroplast
6. Stroma Matrix of the chloroplast Site of light independent reaction/site of dark
reaction
7. Pocket shaped In the lumen of the veins Maintains unidirectional blood flow towards
valves heart.

8. tonsils Sides of the neck Lymph node that localise infection and prevents
it from spreading in the body.
9. A.V. Node Near the interauricular septum near Electrically connects right atrium and right
tricuspid valve/floor of the atrium[right] ventricle/ carries impulse to ventricles through
Bundle of HIS and Purkinje fibres for ventricular
contraction.
10. Mid brain Small tubular part of the brain between Control reflexes involving eye and ear.
fore brain and hind brain.
11. ANS Pair of chains of nerves and ganglia on Prepares the body for violent actions and also
either sides of the back bone. brings the body back to normal once the action is
over.
12. Cerebro spinal Between the meninges, ventricles of Acts like a cushion or protects CNS from injury
fluid brain, central canal of the spinal cord. by absorbing mechanical shock/ forms a medium
for exchange of nutrients, wastes and respiratory
gases.
13. Aqueous Chamber Front chamber in the eye ball between the Filled with aqueous humour which keeps the
lens and cornea. lens moist/ helps to refract light and also
absorbs shock
14. Vitreous Chamber Large cavity between lens and retina Filled with vitreous humour to maintain the
shape of eye ball and protects retina and also
nourishes the inside eye.
15. Vas deferens Arising from each epididymis travelling Transports sperm from the epididymis to the
upward joining to the common urethra. urethra.
16. Oviduct One on the either side of the uterus Site of fertilisation
opening near the ovary on one side and
into the uterus on the other side.
17. Centromere Point of attachment of two sister Helps in connecting the chromosome to the
chromatids. spindle fibre,/ holds the sister chromatids
together.
18. Gene Present on the chromosomes Hereditary features are transmitted by genes.
19. Autosome First 22 pairs of homologous Determine body feature
chromosomes
20. Sex chromosome The last pair of homologous Sex determination
chromosome XX or XY
21. Allele Alternative form of gene occupying same Affect the same character as a gene but in
locus on homologous chromosome different manner
22. Stomata Special openings on the leaf surface Gaseous exchange for photosynthesis/respiration

23. Lenticels Openings on woody/older stem Gaseous exchange for photosynthesis/respiration

24. Cuticle Waxy layer secreted by epidermis on the Prevent transpiration/Protects the leaf
leaf surface

25. Hydathodes Special openings on the margins of leaf, Guttation

at the tips of vein endings
26. Chloroplast Spongy and palisade mesophyll cells of Contains chlorophyll to trap light for photolysis.
leaves
27. Chlorophyll In the walls of thylakoids of chloroplast Absorption of light for photosynthesis

28. RBC Suspended in blood plasma Transportation of respiratory gases like CO2 &
O2
29. WBC Suspended in blood plasma Phagocytosis, Antibody production

30. Platelets Suspended in blood plasma Blood clotting

31. Pericardium A covering surrounding the heart Protects heart from mechanical injury
32.
Pericardial fluid Between 2 walls of pericardium Prevents friction during heart beat
33. Septum Between the left and right heart chambers Prevents the oxygenated and deoxygenated
blood from mixing
34. Coronary artery Arises from base of Aorta to the walls of Provides oxygenated blood to the heart muscles
heart
35. Tricuspid Valve Present at the aperture between Right Prevents backflow of blood from right ventricle
auricle and Right ventricle to right auricle
36. Bicuspid Valve Present at the aperture between left Prevents backflow of blood from left ventricle to
auricle and left ventricle left auricle
37. Pulmonary At opening of right ventricle into Prevent backflow of blood from Pulmonary
semilunar Valve pulmonary artery artery to right ventricle
38. Aortic semilunar At the point of origin of aorta from left Prevent backflow of blood from aorta to left
valve ventricle ventricle
39. Chordae tendinae Arise from muscular projections of Prevents upturning of flaps of valves of heart or
ventricle wall (papillary muscles) to flaps of valves are held in position
the four valves
40. Pacemaker Near the opening of superior venacava Commands start of cardiac cycle
in the right auricle
41. Hepatic portal vein From capillaries of gut to capillaries of Detoxify wastes: Regulate quantity of nutrients
liver in the general blood circulation
42. Spleen Behind stomach above left kidney in Blood reservoir; produce lymphocyte; produce
abdomen RBC; destroy RBC
43. Kidney Either side of backbone protected by last Excretes nitrogenous waste
two ribs
44. Ureter Arises from hilum in the median Conducts urine from kidney to urinary bladder
surface of each kidney & connects
behind with the urinary bladder
at the lower abdomen
45. Hilum Notch in median surface of kidney Ureter arises from hilum
46. Pelvis Funnel shaped expanded end of ureter in Collects urine from collecting tubules
kidney.
47. Urinary bladder In the lower abdomen just above & Urine stored temporarily till it is expelled
behind the pubic bone
48. Urethra Opening of urinary bladder through a Urine output from urinary bladder
tube to outside the body
49. Bowman's capsule Beginning of the nephron/ in the renal Ultrafiltration.
cortex.
50. Glomerulus Knot like mass of blood capillaries closely Ultrafiltration.
fitting in the bowman's capsule

51. PCT between the Loop of Henle and Selective reabsorption, two third of water and
Bowman's capsule in the renal cortex. much of Glucose is reabsorbed.
52. Loop of Henle Renal medulla,, between PCT and DCT. Some absorption of water and sodium ion.

53. DCT Between Loop of Henle and collecting Tubular secretion and reabsorptionof remaining
Duct in Renal Cortex. chlorides and some water.
54. Dendrite Cytoplasmic projections of cell body of Picks up nerve impulses from axon terminal of
neuron. previous neuron.
55. Myelin sheath Covering of axon Insulates axon, protects axon, allows impulse to
move faster.
56. Synapse Junctional gap between axon endings of Impulse transmission from one axon ending to
neuron and dendrite of another neuron. dendrite of next neuron.
57. Meninges Membranous covering of brain and spinal Protects brain from shock and injuries.
cord
58. Corpus callosum Sheet of nerve fibre connecting two Transfers impulses from the right cerebral
cerebral hemispheres./ hemisphere to the left cerebral hemisphere and
Connects right and left cerebral vice versa
hemisphere internally
59. Cerebrum In the forebrain inside the skull. Controls all voluntary actions, thinking,
reasoning, invent, plan, memory.
60. cerebellum Just at the base of the brain under the Coordinate muscular activity and maintain the
cerebrum. body balance,
61. Medulla oblongata Base of skull, lowest portion of the brain. Control activities of internal organ and other
involuntary actions.
62. Thalamus Forebrain/ Diencephalon Relay pain and pressure from body parts to
cerebrum
63. Hypothalamus Forebrain/Below thalamus in Control body temperature & pituitary gland,
diencephalon anger, hunger, thirst
64. Pons Varoli Centre of brain below cerebellum Transmits impulses between two hemispheres of
cerebellum to coordinate muscular activities on
both sides
65. Sympathetic From neck to waist region Prepares body for violent actions
nervous system
66. Parasympathetic Anteriorly ( Head & Neck) Posteriorly Re-establish normal conditions after the violent
nervous system (Sacral) action is over

67. Lacrimal gland Upper sideward portion of orbit Secrete tear for eye protection
68. Conujunctiva Continues with the inner lining of eyelids, Eye layer protection
over cornea
69. Yellow spot Back of eye almost at centre, on eyeball’s Area of best vision due to maximum number of
horizontal axis on retina cones
70. Blind spot Lateral to yellow spot on nasal side of Point of origin of optic nerve, area of no vision
retina
71. Lens Just behind the pupil in front of vitreous Refraction of light & focusing image on retina
humour
72. Ciliary body part of the choroid, lies at the junction of Alter the shape of the lens as per the distance of
choroid and iris the object
73. Suspensory Upper projection of choroid Hold lens in position
ligament
74. Ear ossicles Middle ear, between ear drum & oval Amplifying sound waves by their lever like
window movement & transmits vibration to oval window
75. Ear drum Between auditory canal & ear ossicles Convert sound waves to sound vibrations

76. Eustachian tube Connects middle ear cavity with pharynx Equalizes air pressure on either side of ear
drum, allowing it to vibrate freely

77. Cochlea Inner ear Helps in hearing ,Converts sound vibrations into
nerve impulse
78. Organ of Corti Middle canal of Cochlea Helps in hearing ,Converts sound vibrations into
nerve impulse
79. Utriculus & Main stem connecting Ampulla & Static balance
Sacculus cochlea
80. Ampulla Swollen base of the semicircular canal Dynamic balance

81. Adrenal gland Fitted on top of kidney like cap Secrete adrenaline, glucocorticoids,
mineralocorticoids
82. Pancreas In abdomen below stomach in duodenal Secrete glucagon, insulin, somatostatin.
loop
83. Thyroid gland Front of neck below larynx Secrete thyroxin, calcitonin

84. Pituitary gland Base of midbrain below hypothalamus Secretes gonadotrophin, tropic hormones, ADH,
oxytocin
85. Testes Scrotal sac below abdomen Production of sperms & male hormone

86. Seminiferous Lobules of testis Spermatogenesis

tubule
87. Interstitial cells Between coils of seminiferous tubules Secrete testosterone

88. Epididymis Fitted like cap on the upper pole of the Stores sperm for some day till they mature
testis
89. Seminal vesicle Between posterior surface of urinary Pour a secretion which acts as a medium for
bladder & rectum transport of sperms
90. Prostate gland Surround urethra close to its origin from Pours alkaline secretion which neutralizes the
urinary bladder acid present in female’s vagina
91. Cowper’s gland Open in urethra just before it enters the Secretes lubricant
penis
92. Penis Front of the scrotum, surrounding the Organ of copulation for males.
urethra

93. ovary Abdomen in women Site of Oogenesis

 94. uterus Pelvic cavity between urinary bladder and Receives blastocyst for implantation.
rectum

95. vagina Tubular Lower end of the uterus to Receives sperms from penis during copulation
outside the body

96. acrosome Head of the sperm Secrete Hyaluronidase to diffuse the egg
membrane.

97. placenta Disc likes structure attached to the uterine Diffusion of oxygen, nutrients from mother to
wall made up of uterine and foetal tissue. foetus, acts as endocrine gland and secrete
hormone like progesterone and oestrogen.

98. amnion Sac that surrounds the embryo Protection of foetus as it is filled up of amniotic
fluid

99. Amniotic fluid Inside amnion Protects foetus, maintains even presssure around
the foetus, allows restricted movement of the
foetus.

100 Chorion Around amnion Protection of the growing foetus.

NOTE- This is a sample list for location and function. Students may add more to this list as per ICSE 2024 syllabus.