Single step large mutation leading to speciation is also called:
Show Hint
- founder effect
- saltation
- branching descent
- natural selection
The Correct Option is B
Solution and Explanation
Top Questions on A Brief Account Of Evolution
- Interferons are proteins secreted by:
- CBSE CLASS XII - 2024
- Biology
- A Brief Account Of Evolution
- (ii) How does geitonogamy differ from xenogamy?
- CBSE CLASS XII - 2024
- Biology
- A Brief Account Of Evolution
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- CBSE CLASS XII - 2024
- Biology
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- Biology
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[0.5cm]- CBSE CLASS XII - 2024
- Biology
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Questions Asked in CBSE CLASS XII exam
Consider the DataFrame Doctor shown below:
Write suitable Python statements for the following:
(i) To print the last three rows of the DataFrame Doctor.
(ii) To display the names of all doctors.
(iii) To add a new column 'Discount' with value of 200 for all doctors.
(iv) To display rows with index 2 and 3.
(v) To delete the column 'Department'.
- CBSE CLASS XII - 2025
- Python Libraries
XYZ Technologies, Hyderabad is a company that deals with data science and AI projects. They have different divisions: ADMIN, SALES, PRODUCTION and SERVICE. The layout of the Hyderabad branch is:
The management wants to connect all the devisions as well as the computers of each devision (ADMIN, SALES, PRODUCTION and SERVICE.
Based on the above specifications, answer the following questions:
(i) Suggest the topology and draw the most suitable cable layout for connecting all the divisions in the Hyderabad office.
(ii) XYZ Technologies is having its head office in the USA. Out of LAN, MAN and WAN, which kind of network will be created to connect Hyderabad office with USA Office? Justify your answer.
(iii) Suggest the division for the placement of server. Explain the reason for your selection.
(iv) Suggest the placement of Switch/Hub with justification.
(v) Where will a repeater be placed in the suggested network layout? Justify your answer.
- CBSE CLASS XII - 2025
- Information Technology
Ashutosh, who is a manager, has created a database to manage employee records. The database includes a table named EMPLOYEE whose attribute names are mentioned below:
EID : Stores the unique ID for each employee.
EMP_NAME : Stores the name of the employee.
DEPT : Stores the department of the employee.
SALARY : Stores the salary of the employee.
JOIN_DATE : Stores the employee’s joining date.
Write the output of the following SQL Queries:
(i) SELECT SUBSTRING(EMP_NAME, 1, 5) FROM EMPLOYEE WHERE DEPT = 'ENGINEERING';
(ii) SELECT EMP_NAME FROM EMPLOYEE WHERE MONTH(JOIN_DATE) = 8;
(iii) SELECT EMP_NAME FROM EMPLOYEE WHERE SALARY>60000;
(iv) SELECT COUNT(DEPT) FROM EMPLOYEE;
- CBSE CLASS XII - 2025
- SQL Queries
An educational institution is maintaining a database for storing the details of courses being offered. The database includes a table COURSE with the following attributes:
C_ID : Stores the unique ID for each course.
C_NAME : Stores the course’s name.
INSTRUCTOR : Stores the name of the course instructor.
DURATION : Stores the duration of the course in hours.
Write SQL queries for the following:
(i) To add a new record with following specifications:
C_ID : C106
C_NAME : Introduction to AI
INSTRUCTOR : Ms. Preeti
DURATION : 55
(ii) To display the longest duration among all courses.
(iii) To count total number of courses run by the institution.
(iv) To display the instructors’ name in lower case.
- CBSE CLASS XII - 2025
- SQL Queries
(A) Explain the following reactions and write chemical equations involved:
(a) Wolff-Kishner reduction
(b) Etard reaction
(c) Cannizzaro reaction- CBSE CLASS XII - 2025
- Oxidation And Reduction Reactions