All questions of Cells for Grade 8 Exam

The cell was first discovered and named by Robert Hooke in 1665. He remarked that it looked strangely similar to cellula or small rooms which monks inhabited, thus deriving the name. However what Hooke actually saw was the dead cell walls of plant cells (cork) as it appeared under the microscope.

Option c

Because a hen's whole egg is a cell, which you call yolk.
hope it helps
Tirtha Yeole
legends group

Explanation:-
The Amoeba is not a multicellular organism instead amoeba is an unicellular organism .
Thus, the given statement is false .

The correct answer is B

**Explanation:**

**Introduction:**
Ostrich eggs are the largest eggs produced by any living bird species. They are laid by female ostriches, which are flightless birds native to Africa. Ostrich eggs are known for their large size and unique characteristics.

**Visual Appearance:**
Ostrich eggs are indeed visible to the naked eye due to their size. They are about 15-18 centimeters in length and weigh around 1.4 kilograms on average. This makes them the largest eggs produced by any bird species. The size of an ostrich egg is approximately equal to 24 chicken eggs.

**Shell Structure:**
The shell of an ostrich egg is extremely thick and sturdy. It is composed of multiple layers, including a hard outer layer and a porous inner layer. The outer layer protects the egg from external damage, while the inner layer allows for gas exchange during incubation.

**Cellular Composition:**
Like all eggs, an ostrich egg contains cells within it. However, it is important to note that the cells present in an ostrich egg are not visible to the naked eye. The cells are microscopic in size and require magnification, such as a microscope, to be seen.

**Misinterpretation:**
The question seems to imply that the ostrich egg itself is a single cell visible to the naked eye. However, this is a misinterpretation. The ostrich egg is a structure produced by the female ostrich's reproductive system, which contains multiple cells within it. These cells are not individually visible without the aid of magnification.

**Conclusion:**
In conclusion, the statement that an ostrich egg is a cell visible to the naked eye is false. While the egg itself is visible due to its large size, it is composed of multiple cells that are not individually visible without magnification. Ostrich eggs are fascinating structures worth studying, but their cellular composition requires the use of scientific tools to observe at a microscopic level.

And nucleus because it controls the cell

Chloroplast is found in the:


There are four options given and we need to determine which one is correct.
A: Plant cell only
- Chloroplasts are specialized organelles found in plant cells.
- They are responsible for photosynthesis, the process by which plants convert sunlight into energy.
B: Animal cell only
- Animal cells do not contain chloroplasts.
- They obtain energy through other means such as cellular respiration.
C: Both of these
- This option is not correct because chloroplasts are only found in plant cells, not animal cells.
D: None of these.
- This option is also not correct because chloroplasts are indeed found in plant cells.
Conclusion:
- The correct answer is A: Plant cell only.
- Chloroplasts are unique to plant cells and play a crucial role in the process of photosynthesis.

Single celled organisms only have one cell and hence they are also called unicellular(uni means one and cellular means cell)

Because microscope is nachine help in view very tiny object.

The function unit of the life is called cell.

Animal don't require it

Answer:

Explanation:
The correct answer to the question is option B: Group of cells. Here's a detailed explanation of why tissue is a group of cells:
1. Tissue definition: Tissue refers to a group or collection of similar cells that work together to perform a specific function in the body.
2. Cell definition: A cell is the basic structural and functional unit of all living organisms. It is the smallest unit of life and can carry out various functions necessary for the survival and functioning of an organism.
3. Tissue composition: Tissues are composed of a group of cells that are similar in structure and function. These cells are organized and work together to perform a specific task or function in the body.
4. Types of tissues: There are four main types of tissues in the human body: epithelial tissue, connective tissue, muscle tissue, and nervous tissue. Each type of tissue is composed of specific cells that have specialized functions.
5. Functions of tissues: Tissues play a vital role in maintaining the structure and function of organs and systems in the body. They provide support, protection, and coordination of various activities.
In conclusion, tissue is a group of cells that work together to perform a specific function in the body. It is an essential component of the human body and is responsible for the proper functioning of organs and systems.