1.which blood cell of your body act as a defense against infection ?

Ans:- W.B. C(white blood corpuscles)
WBC is also called as leukocytes. A healthy human being has about 4000-10000 WBC per cubic millimetre of blood. If the number of WBC will decrease then the disease will be happened. An increase in number of WBC above 12000 is called leucocytosis. A decrease below 600 is called leucopenia.

2.which blood cell of your body helps in respiration ?

Ans:-R.B. C(red blood corpuscles)
RBC is also called as Erythrocytes. The process of formation of RBC is called as erythropoiesis . It is produced from bone marrow. A hormone erythropoietin in kidney nitiates erythropoiesis. It transports oxygen nutrients to lungs and tissue. The life span of RBC is 120 days.

3.what is the longest cell of your body ?

Ans:- Neurons are the unit of nervous system.

It transmits impulse/ information throughout the body.

4.what is the largest cell in human body ?

Ans:-ovum.
Ovum is the female reproductive cell and helps in reproduction. It is produce from ovaries and it is non motile.

5.what is the smallest cell in human body ?

Ans:-Sperm cell
Sperm is the male reproductive cell,combine with ovum form zygote. It is motile.

6. How many bones found in a human child?

Ans:-300 bones
Adult human being had 206 bone.

7.what is the longest bone in human body?

Ans:- Femur
It is also called as thigh-bone found in between hip and knee.
It is also the strongest bone in human body.

8. What is the smallest bone of human body ?

Ans:-stapes
It is found on middle ear. It transports sound vibration to middle ear.

9.what is the largest muscle in human body ?

Ans:-Gluteus maximum

It is also called as buttock & found on the back of the hip.It is the largest muscle of the body basically keep the trunk posture erect .

10.what is the smallest muscle in human body ?

Ans:-Stapedius muscle
It is found near Stapes in middle ear.

11.What is the name of hardest working muscle of human body ?

Ans :- Cardiac muscle

Cardiac muscle are found in the heart . It works every time in a person’s life . It’s main work is to pump blood. It pumps 70 grams blood in every pump. It was estimated that an average life person’s heart beat about 3 billon time.

12. Which part of the human body maintain posture & equilibrium in human body ?

Ans- Cerebellum

It was found in the back of the brain. It helps to maintain balance , posture in human body .

13. How many pair of cranial nerve found in human body ?

Ans:- 12 pairs

Cranial nerves are emerges from the brain , concerned with gland , muscle  & sense organ of human body . The name of these nerves are given below-

1- Olfactory

2-optic

3-Oculomotor

4-trochlear

5-Trigeminal

6-abdunces

7-facial

8- Auditory

9-Glossopharyngeal

10-vagus

11- spinal accessory

12- Hypoglossal

14. how many pair of spinal nerve are present in human body ?

Ans:- 31 pairs

Spinal cord are arise from the spinal cord of human body . these spinal nerve are divided into 5 groups-

1.Cervical spinal nerve- 8 pairs

2.Thoracic Nerve- 12 pairs

3.Lumbar nerves-5 pairs

4.Sacral nerve-5 pairs

5.cocygeal nerve- 1 pairs

15.What is the name of most complex organ of human body ?

Ans:- Brain

Human brain is the largest brain among vertebrates. It makes 2 percent weight of a human body . an average humans brain weigh about 1200-1600 gm .It consist grey matter & white matter .

16. What is the name of largest organ of human body ?

Ans:- Skin

Skin is the largest organ of human body. It weight about 4 kilogram and extend up to 22 square feet .

17 . What is the 2nd largest organ of human body ?

Ans:- Liver

Liver is weigh about 1600 gram in a average human body. It generate heat in the body.  It also filter the toxic chemical from the human body and remove it in the form of stool.