Class 12 Biology Human Health and Disease 1 Mark Questions
1 Mark Questions for Class 12 Biology Human Health and Disease. Try first, then reveal the answer. These are exam-oriented practice items, not copied board papers.
Practice questions aligned to NCERT topics used in CBSE classrooms. These are original exam-oriented questions for revision — not official CBSE board papers and not a guarantee of any exam question. Always match the textbook issued by your school and the latest PDFs on ncert.nic.in and cbseacademic.nic.in.
Answers opened: 0
Practice set
Q1MCQ1 markEasyRevision pick
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
A. CBSE often tests a concept by asking a daily-life example from the same chapter
B. Innate vs acquired immunity
C. AIDS, malaria, cancer as in NCERT
D. Human Health and Disease is an NCERT chapter taught in CBSE Class 12 Biology
Answer
B. Innate vs acquired immunity
Explanation
Innate vs acquired immunity. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q2MCQ1 markEasy
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
A. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
B. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
C. Antibodies
D. Adolescence and drugs
Answer
C. Antibodies
Explanation
Antibodies. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q3MCQ1 markEasy
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
A. Write three points from Human Health and Disease in your own words; that is enough for a short-answer start
B. Every chapter ends with keywords or a summary that is useful for one-mark answers
C. Vaccination
D. AIDS, malaria, cancer as in NCERT
Answer
D. AIDS, malaria, cancer as in NCERT
Explanation
AIDS, malaria, cancer as in NCERT. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q4MCQ1 markEasy
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
A. Use the terms used in the NCERT book; do not replace them with unofficial names
B. Human Health and Disease is an NCERT chapter taught in CBSE Class 12 Biology
C. CBSE often tests a concept by asking a daily-life example from the same chapter
D. Adolescence and drugs
Answer
D. Adolescence and drugs
Explanation
Adolescence and drugs. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q5MCQ1 markModerateRevision pick
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
A. Mix MCQs with short answers so you remember both facts and explanations from Human Health and Disease
B. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
C. Vaccination
D. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
Answer
C. Vaccination
Explanation
Vaccination. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q6MCQ1 markEasy
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
A. Human Health and Disease is an NCERT chapter taught in CBSE Class 12 Biology
B. Write three points from Human Health and Disease in your own words; that is enough for a short-answer start
C. Every chapter ends with keywords or a summary that is useful for one-mark answers
D. Adolescence and drugs
Answer
A. Human Health and Disease is an NCERT chapter taught in CBSE Class 12 Biology
Explanation
Human Health and Disease is an NCERT chapter taught in CBSE Class 12 Biology. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q7MCQ1 markEasy
Choose the correct statement related to Textbook first in the chapter Human Health and Disease.
A. The textbook says the opposite of this statement
B. CBSE often tests a concept by asking a daily-life example from the same chapter
C. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
D. Use the terms used in the NCERT book; do not replace them with unofficial names
Answer
C. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
Explanation
Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q8MCQ1 markEasy
Choose the correct statement related to Keywords in the chapter Human Health and Disease.
A. This happens only in a laboratory and never in daily life
B. Mix MCQs with short answers so you remember both facts and explanations from Human Health and Disease
C. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
D. Every chapter ends with keywords or a summary that is useful for one-mark answers
Answer
D. Every chapter ends with keywords or a summary that is useful for one-mark answers
Explanation
Every chapter ends with keywords or a summary that is useful for one-mark answers. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q9MCQ1 markEasyRevision pick
Choose the correct statement related to Examples in the chapter Human Health and Disease.
A. This idea is not part of the NCERT chapter
B. Write three points from Human Health and Disease in your own words; that is enough for a short-answer start
C. CBSE often tests a concept by asking a daily-life example from the same chapter
D. Innate vs acquired immunity
Answer
C. CBSE often tests a concept by asking a daily-life example from the same chapter
Explanation
CBSE often tests a concept by asking a daily-life example from the same chapter. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q10MCQ1 markModerate
Choose the correct statement related to Diagrams in the chapter Human Health and Disease.
A. Antibodies
B. Use the terms used in the NCERT book; do not replace them with unofficial names
C. The textbook says the opposite of this statement
D. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
Answer
D. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
Explanation
If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q11MCQ1 markEasy
Choose the correct statement related to Revision in the chapter Human Health and Disease.
A. Write three points from Human Health and Disease in your own words; that is enough for a short-answer start
B. AIDS, malaria, cancer as in NCERT
C. This happens only in a laboratory and never in daily life
D. Mix MCQs with short answers so you remember both facts and explanations from Human Health and Disease
Answer
A. Write three points from Human Health and Disease in your own words; that is enough for a short-answer start
Explanation
Write three points from Human Health and Disease in your own words; that is enough for a short-answer start. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q12MCQ1 markEasy
Choose the correct statement related to Accuracy in the chapter Human Health and Disease.
A. This idea is not part of the NCERT chapter
B. Use the terms used in the NCERT book; do not replace them with unofficial names
C. Innate vs acquired immunity
D. Adolescence and drugs
Answer
B. Use the terms used in the NCERT book; do not replace them with unofficial names
Explanation
Use the terms used in the NCERT book; do not replace them with unofficial names. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q13MCQ1 markEasyRevision pick
Choose the correct statement related to Practice in the chapter Human Health and Disease.
A. Mix MCQs with short answers so you remember both facts and explanations from Human Health and Disease
B. The textbook says the opposite of this statement
C. Vaccination
D. Antibodies
Answer
A. Mix MCQs with short answers so you remember both facts and explanations from Human Health and Disease
Explanation
Mix MCQs with short answers so you remember both facts and explanations from Human Health and Disease. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q14MCQ1 markEasy
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
A. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
B. This happens only in a laboratory and never in daily life
C. Adolescence and drugs
D. Innate vs acquired immunity
Answer
D. Innate vs acquired immunity
Explanation
Innate vs acquired immunity. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q15MCQ1 markModerate
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
A. Vaccination
B. Every chapter ends with keywords or a summary that is useful for one-mark answers
C. Innate vs acquired immunity
D. Antibodies
Answer
D. Antibodies
Explanation
Antibodies. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q16MCQ1 markEasy
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
A. CBSE often tests a concept by asking a daily-life example from the same chapter
B. AIDS, malaria, cancer as in NCERT
C. Antibodies
D. Human Health and Disease is an NCERT chapter taught in CBSE Class 12 Biology
Answer
B. AIDS, malaria, cancer as in NCERT
Explanation
AIDS, malaria, cancer as in NCERT. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q17MCQ1 markEasyRevision pick
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
A. AIDS, malaria, cancer as in NCERT
B. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
C. Adolescence and drugs
D. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
Answer
C. Adolescence and drugs
Explanation
Adolescence and drugs. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q18MCQ1 markEasy
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
A. Adolescence and drugs
B. Write three points from Human Health and Disease in your own words; that is enough for a short-answer start
C. Every chapter ends with keywords or a summary that is useful for one-mark answers
D. Vaccination
Answer
D. Vaccination
Explanation
Vaccination. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q19MCQ1 markEasy
Choose the correct statement related to Human Health and Disease in the chapter Human Health and Disease.
A. Vaccination
B. Human Health and Disease is an NCERT chapter taught in CBSE Class 12 Biology
C. This topic is only for college
D. Antibodies
Answer
B. Human Health and Disease is an NCERT chapter taught in CBSE Class 12 Biology
Explanation
Human Health and Disease is an NCERT chapter taught in CBSE Class 12 Biology. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q20MCQ1 markModerate
Choose the correct statement related to Textbook first in the chapter Human Health and Disease.
A. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
B. Human Health and Disease is an NCERT chapter taught in CBSE Class 12 Biology
C. If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures
D. Mix MCQs with short answers so you remember both facts and explanations from Human Health and Disease
Answer
A. Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions
Explanation
Read the definitions, diagrams and solved examples in the NCERT textbook before practising extra questions. The other options mix ideas from nearby topics or reverse the textbook fact.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q211 Mark1 markEasy
Define or state: Keywords.
Answer
Every chapter ends with keywords or a summary that is useful for one-mark answers.
Explanation
A one-mark answer should use the textbook term and one clear fact — not a long paragraph.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q221 Mark1 markEasy
Define or state: Examples.
Answer
CBSE often tests a concept by asking a daily-life example from the same chapter.
Explanation
A one-mark answer should use the textbook term and one clear fact — not a long paragraph.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q231 Mark1 markEasy
Define or state: Diagrams.
Answer
If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures.
Explanation
A one-mark answer should use the textbook term and one clear fact — not a long paragraph.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q241 Mark1 markEasy
Define or state: Revision.
Answer
Write three points from Human Health and Disease in your own words; that is enough for a short-answer start.
Explanation
A one-mark answer should use the textbook term and one clear fact — not a long paragraph.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q251 Mark1 markModerate
Define or state: Accuracy.
Answer
Use the terms used in the NCERT book; do not replace them with unofficial names.
Explanation
A one-mark answer should use the textbook term and one clear fact — not a long paragraph.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q261 Mark1 markEasy
Define or state: Practice.
Answer
Mix MCQs with short answers so you remember both facts and explanations from Human Health and Disease.
Explanation
A one-mark answer should use the textbook term and one clear fact — not a long paragraph.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q271 Mark1 markEasy
Define or state: Human Health and Disease.
Answer
Innate vs acquired immunity.
Explanation
A one-mark answer should use the textbook term and one clear fact — not a long paragraph.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q281 Mark1 markEasy
Define or state: Human Health and Disease.
Answer
Antibodies.
Explanation
A one-mark answer should use the textbook term and one clear fact — not a long paragraph.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q291 Mark1 markEasy
Define or state: Human Health and Disease.
Answer
AIDS, malaria, cancer as in NCERT.
Explanation
A one-mark answer should use the textbook term and one clear fact — not a long paragraph.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q301 Mark1 markModerate
Define or state: Human Health and Disease.
Answer
Adolescence and drugs.
Explanation
A one-mark answer should use the textbook term and one clear fact — not a long paragraph.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q61Assertion and Reason1 markModerate
Assertion (A): CBSE often tests a concept by asking a daily-life example from the same chapter.
Reason (R): Examples is a key idea in the chapter Human Health and Disease.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q62Assertion and Reason1 markModerate
Assertion (A): If the chapter has a diagram, practise labelling it — many school tests ask for labelled figures.
Reason (R): Diagrams is a key idea in the chapter Human Health and Disease.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q63Assertion and Reason1 markModerate
Assertion (A): Write three points from Human Health and Disease in your own words; that is enough for a short-answer start.
Reason (R): Revision is a key idea in the chapter Human Health and Disease.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q64Assertion and Reason1 markDifficult
Assertion (A): Use the terms used in the NCERT book; do not replace them with unofficial names.
Reason (R): Accuracy is a key idea in the chapter Human Health and Disease.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q65Assertion and Reason1 markModerate
Assertion (A): Mix MCQs with short answers so you remember both facts and explanations from Human Health and Disease.
Reason (R): Practice is a key idea in the chapter Human Health and Disease.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q66Assertion and Reason1 markModerate
Assertion (A): Innate vs acquired immunity.
Reason (R): Human Health and Disease is a key idea in the chapter Human Health and Disease.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q67Assertion and Reason1 markModerate
Assertion (A): Antibodies.
Reason (R): Human Health and Disease is a key idea in the chapter Human Health and Disease.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q68Assertion and Reason1 markDifficult
Assertion (A): AIDS, malaria, cancer as in NCERT.
Reason (R): Human Health and Disease is a key idea in the chapter Human Health and Disease.
Choose the correct option.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer
A. Both A and R are true, and R is the correct explanation of A.
Explanation
Read Assertion and Reason separately first. Here both match the textbook idea, and R explains why A is taught in this chapter.
Meta
Class: Class 12 · Subject: Biology · Chapter: Human Health and Disease · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
FAQs
Are these official CBSE board questions?
No. They are original practice questions aligned to NCERT topics used in CBSE classrooms. Official sample papers are published on cbseacademic.nic.in.
Will these questions appear in the board exam?
Nobody can promise a question. Use them for revision of frequently tested concepts and exam-style practice.
Is the chapter list the latest NCERT list?
Yes, the catalog follows current NCERT textbooks used in CBSE schools (including new middle-stage books such as Ganita Prakash and Curiosity). Always match the book issued by your school.
How should I use the 100 questions?
Try the question first, then tap Show answer. Mix MCQs with long answers. Revise formulas and diagrams from the textbook alongside this set.
Where are NCERT solutions?
Open the NCERT-style practice link on this subject or chapter. For word-for-word textbook exercise answers, use the NCERT book itself; we do not copy solution keys from other websites.
What is the suggested URL pattern?
Hub /cbse/, then /cbse/class-12/, then subject and chapter slugs.
Why is this a separate URL?
So students searching for “1 Mark Questions” land on a filtered set, while the chapter page remains the full 100-question bank. Same facts, different search intent.
Today's 3-step path
Follow this loop every day: mixed test, current affairs, then today's subject. A new set arrives tomorrow.