Download App

Human Health and Disease — BIOLOGY STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceBIOLOGYHuman Health and Disease5 Marks
Question
Discuss the different barrier of innate immunity.
✓

Answer

It is accomplished by providing different types of barriers:
  1. Physical barriers: These barriers do not allow pathogens and foreign agents to enter the body, e.g., skin, mucous membranes of digestive, respiratory and urinogenital tracts trapping microorganisms.
  2. Physiological barriers: Sweat, tears, acid in the stomach and saliva prevent microbial growth.
  3. Cellular barriers: WBCs (polymorphonuclear leukocytes and monocytes, natural killer lymphocytes) and macrophages phagocytose and destroy microbes.
  4. Cytokine barriers: Interferons produced by virus-infected cells protect non-infected cells from further viral infection.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "5 Marks Questions" from Human Health and Disease→Human Health and Disease — all question types→BIOLOGY STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Write short notes on the followings : (a) Predation (b) Competition
→
(i) Define standing crop.
(ii) Explain important steps in the process of decomposition in a terrestrial ecosystem.
→
DNA separated from one cell, when introduced in another cell, is able to bestow some of the properties of the former to the latter. What is this change called in technical terms? Describe the experiment evidences which led to the discovery of the above phenomenon.
→
  1. Comment on the pattern in which all communities undergo a change in composition and structure with changing environmental conditions.
  2. Explain 'climax community' and 'sere'.
  3. Differentiate between primary and secondary Succession, with examples.
→
Describe briefly about embryonic stages in human being.
→
Match the items of column A with those given in column B.
S. No
Column A
S. No
Column B
(i)
Eli Lilly
(a)
Cotton bollworm
(ii)
Pest resistance
(b)
Meloidegyne incognitia
(iii)
Crylab
(c)
Golden Rice
(iv)
CryIAC
(d)
Humulin
(v)
RNAi
(e)
Corn borer
(vi)
Vitamin A
(f)
Bt cotton
→
(i) Define net primary productivity.
(ii) Explain with diagram that the pyramid of energy is always upright.
→
A woman with blood group “A” marries a man with blood group “O”. Discuss the possibilities of the inheritance of the blood groups in the following starting with “yes” or “no” for each:
  1. They produce children with blood group “A” only.
  2. They produce children some with “O” blood group and some with “A” blood group.
→
Answer the following questions:
During a cross involving true breeding red flowered and true breeding white flowered snapdragon plants, the $F_1$ progeny did not show any of the parental traits, while they reappeared in $F_2$ progenies. Explain the mechanism using Punnett Square.
→
Describe female reproductive system.
→