Class 9 - 12 - Biology - Know About Disease - Brief Notes About AIDS (#cbsenotes)(#eduvictors)

AIDS(A Brief Introduction)

Meaning of AIDS

✤ The word AIDS stands for Acquired Immuno Deficiency Syndrome. This means a deficiency of the immune system, acquired during the lifetime of an individual indicating that it is not a congenital disease [disease or abnormality present from birth]. ‘Syndrome’ means a group of symptoms.


✤ AIDS was first reported in 1981 and in the last twenty-five years or so, it has spread all over the world.

✤ Luc Montagnier, Françoise Barré-Sinoussi, and their colleagues at the Pasteur Institute in Paris were the first to report the discovery of the virus now called the human immunodeficiency virus (HIV) associated with AIDS.


Causes of AIDS

CBSE Class 9 - Cell Biology - 7 Points about Plasmolysis (#cbsenotes)(#eduvictors)

Cell Biology - 7 Points about Plasmolysis

Plasmolysis vs Flaccid vs Turgid
Credits: Wikimedia, Author: LadyOfHats

1. When a living plant cell loses water through osmosis there is shrinkage or contraction of the contents of the cell away from the cell wall. This phenomenon is known as plasmolysis
(plasma → fluid; lysis → disintegration, decomposition).


2. Only living cells, and not dead cells, are able to absorb water by osmosis.


3. Cell walls permit the cells of plants, fungi and bacteria to withstand very dilute [hypotonic] external media without shrinkage.

Class 9 - Biology - Improvement in Food Resources - Agriculture Improvements (Very Short Questions and Answers) (#cbsenotes)(#eduvictors)

Improvement in Food Resources - Agriculture Improvements 

(Very Short Questions and Answers) 

Q1: Define crop.

Q2: Name the two major problems for food requirements due to overpopulated country like India?

Q3: Give two examples of scientific management practices to obtain a high yield of crops.

Q4: What are integrated farming practices?

Q5: Give three examples of cereals? Which type of major nutrient do they provide?

Q6: Lentils are rich in ________. Lentils, black gram (urad), green gram (moong) are collectvely called _________.

Q7: Give three examples of oilseeds? Name the major nutrient provided by them.

Q8: What do vegetables, spices and fruits provide?

Q9: What are fodder crops? Give three examples of fodder crops.

Q10: Define photoperiodism. What is its effect on plants?

CBSE CLASS 9 - BIOLOGY - CELL: FUNDAMENTAL UNIT OF LIFE (Worksheet)(#cbsenotes)(#eduvictors)

CELL: FUNDAMENTAL UNIT OF LIFE 

(Worksheet)

Fill in the blanks with suitable words.

1. The fundamental organizational unit of life is the _______.


2. Cells are enclosed by a plasma membrane composed of ________ and _______.


3. Plasma membrane is a __________ permeable membrane.


4. In plant cells, a cell wall composed of _________ is located outside the cell membrane.


5. In prokaryotes, the nuclear membrane is ________.

CBSE Class 9 - Science - Why do we Fall ill? (MCQs)

Why do we Fall ill? 

(MCQs)

Q1: Which one of the following is an infectious disease?

(a) diptheria
(b) diabetes
(c) hypertension
(d) cancer


Q2: Elephantiasis disease can have

(a) short-term affect on our health
(b) no effect on our health
(c) long term affect on our health
(d) sometimes bad effect on our health

CBSE Class 9 - Biology - CH6 - Tissues (Set-1)

PLANT TISSUES 

MCQs, NCERT Chapter Solutions and Q & A (asked in CBSE examination)

MCQs

Q1: The study of tissues is called ...
a) cytology
b) embryology
c) histology
d) pathology

Answer: c) histology


Q:2 Which of the following statement is NOT true?
(a) Most of the plant tissues are the supportive type.
(b) Tissues ensure the division of labour.
(c) Sedentary existence contributes to the organ system design in animals.
(d) Organ systems are far more complex in animals than in plants.

Class 9 - Chapter 5 - Cell - Fundamental Unit of Life - NCERT Q & A #class9-biology #eduvictors

Fundamental Unit of Life 

NCERT Q & A

Q1: Who observed the cells the first time?
Answer: Robert Hooke. He observed a thin slice of cork cells under a simple microscope.

 

Simple Microscope made by Robert Hooke (credits: Wikipedia)

Q2: Define Cell

Answer: The cell is the structural and functional unit of life.

Q3: Who proposed the cell theory?

Answer: Schleiden (1838) and Schwann (1839).

Q4: Who expanded cell theory by suggesting that all cells arise from pre-existing cells?

Answer: Virchow (1855.

Q5: In which year the electron microscope was invented?

Answer: 1940

Q6: Name the book in which Robert Hooke published his observations about cork cells.

Answer: Micrographia.