1.
What is plasma?
Correct Answer
B. A liquid blood component containing blood cells
Explanation
Plasma is a liquid blood component that contains blood cells. It is the yellowish fluid that makes up about 55% of the total blood volume. Plasma carries various substances such as nutrients, hormones, waste products, and antibodies throughout the body. It also helps maintain blood pressure and regulates body temperature.
2.
Which of these is known as a type of cell?
Correct Answer
D. All of these
Explanation
All of these options are types of cells. Connective cells are responsible for connecting and supporting tissues and organs. Muscle cells are specialized for contraction and movement. Nervous cells, also known as neurons, transmit electrical signals and are involved in communication within the nervous system. Therefore, all of these options are correct as they represent different types of cells.
3.
What keeps the structure of plant cell walls strong and stable?
Correct Answer
C. Cellulose
Explanation
Cellulose is a complex carbohydrate that provides structural support to plant cell walls. It forms a rigid network of fibers that gives strength and stability to the cell wall, allowing plants to maintain their shape and withstand external pressure. Cellulose is the main component of plant cell walls and is responsible for their ability to resist mechanical stress and provide protection to the cell.
4.
Which of these does the protoplast include?
Correct Answer
C. Both A & B
Explanation
The protoplast includes both the cell membrane and the protoplasm. The cell membrane is the outer boundary of the protoplast, while the protoplasm refers to the living contents of the cell, including the cytoplasm and the cell organelles. Therefore, both A (cell membrane) and B (protoplasm) are included in the protoplast.
5.
How many genes are found in a human cell?
Correct Answer
A. Between 20,000 and 25,000
Explanation
The correct answer is between 20,000 and 25,000. This is the estimated number of genes found in a human cell. Genes are segments of DNA that contain instructions for building proteins, which are essential for the functioning of cells and the human body. The human genome project, a scientific research project, estimated that the human genome contains approximately 20,000 to 25,000 protein-coding genes. These genes are responsible for various traits and characteristics in humans.
6.
Which tissue covers and protects parts of the body?
Correct Answer
B. Epithelial tissue
Explanation
Epithelial tissue covers and protects parts of the body. It forms the outer layer of the skin and lines the internal organs, blood vessels, and body cavities. This tissue acts as a barrier, protecting the underlying tissues from mechanical injury, pathogens, and dehydration. It also helps in absorption, secretion, and sensation. Epithelial tissue is composed of tightly packed cells with little to no extracellular matrix, allowing it to provide a protective and selective barrier.
7.
A group of cells with similar characteristics that work together is called
Correct Answer
B. Tissue
Explanation
A group of cells with similar characteristics that work together is called tissue. Tissues are formed when cells of the same type come together to perform a specific function. They can be found in various parts of the body and are essential for the proper functioning of organs and organ systems. Tissues can be classified into four main types: epithelial, connective, muscle, and nervous tissue. Each type of tissue has its own unique characteristics and functions, allowing them to work together efficiently and effectively.
8.
Blood cell that helps destroy germs is known as the
Correct Answer
B. White blood cell
Explanation
White blood cells, also known as leukocytes, are responsible for defending the body against foreign invaders such as bacteria, viruses, and parasites. They play a crucial role in the immune response by identifying and destroying these germs through various mechanisms, including phagocytosis, where they engulf and digest the pathogens. Unlike red blood cells, which primarily carry oxygen, white blood cells are specialized for immune defense and are an essential component of the body's immune system.
9.
Which of these is a type of osmotic solution?
Correct Answer
C. Both A & B
Explanation
Both isotonic and hypertonic solutions are types of osmotic solutions. Isotonic solutions have the same concentration of solutes as the cells, resulting in no net movement of water across the cell membrane. Hypertonic solutions have a higher concentration of solutes than the cells, causing water to move out of the cells and resulting in cell shrinkage. Therefore, both A (isotonic) and B (hypertonic) are correct answers for the given question.
10.
Which cell in the blood carries oxygen?
Correct Answer
B. Red blood cell
Explanation
Red blood cells, also known as erythrocytes, are responsible for carrying oxygen throughout the body. They contain a protein called hemoglobin, which binds to oxygen in the lungs and transports it to the body's tissues and organs. This process is essential for the delivery of oxygen to cells, allowing them to produce energy and carry out their functions. White blood cells, on the other hand, are part of the immune system and are involved in fighting infections and diseases. Vacuoles are membrane-bound organelles found in plant and animal cells, responsible for storing various substances. "Terrorist cell" is not a valid term in the context of blood cells.
11.
The small round structures that make proteins are known as
Correct Answer
B. Ribosomes
Explanation
Ribosomes are small round structures that are responsible for protein synthesis in cells. They are found in both prokaryotic and eukaryotic cells and can be free-floating in the cytoplasm or attached to the endoplasmic reticulum. Ribosomes read the genetic information in mRNA and use it to assemble amino acids into proteins. They play a crucial role in cellular processes and are essential for the growth and maintenance of cells. Therefore, ribosomes are the correct answer for the small round structures that make proteins.
12.
In living things, what's the basic unit of the structure called?
Correct Answer
C. Cell
Explanation
The basic unit of structure in living things is called a cell. Cells are the smallest functional and structural units of an organism and are responsible for carrying out all the necessary functions of life. They are the building blocks of tissues, organs, and systems within the body. Without cells, living organisms would not be able to perform essential processes such as growth, reproduction, and metabolism. Cells contain various organelles and molecules that work together to maintain the overall structure and function of the organism.
13.
In the mitosis process, the parent cell divides into _____ identical daughter cells.
Correct Answer
B. Two
Explanation
During mitosis, the parent cell undergoes a series of stages that result in the formation of two identical daughter cells. This process involves the replication and division of the genetic material, followed by the separation of the duplicated chromosomes into two separate nuclei. Each daughter cell receives an equal share of the genetic material and cellular components, resulting in two identical cells. Therefore, the correct answer is "Two."
14.
Which of these is not a part of plasma?
Correct Answer
B. Platelets
Explanation
Platelets are not a part of plasma. Plasma is the liquid component of blood that carries various substances such as water, proteins, electrolytes, hormones, and waste products. Platelets, on the other hand, are small cell fragments that play a crucial role in blood clotting. They are produced in the bone marrow and are involved in the formation of blood clots to prevent excessive bleeding. Therefore, platelets are not a part of plasma.
15.
What's known as the cell's brain?
Correct Answer
A. Nucleus
Explanation
The nucleus is known as the cell's brain because it contains the cell's genetic material, including DNA, which controls the cell's activities and determines its characteristics. The nucleus regulates the synthesis of proteins and is involved in cell division and growth. It acts as the control center of the cell, directing its functions and maintaining its integrity. The nucleus also plays a role in storing and transmitting genetic information to future generations of cells.
16.
What percentage of water does the cytoplasm contain?
Correct Answer
C. About 80 percent
Explanation
The cytoplasm is a gel-like substance that fills the cell and contains various organelles. It is composed mostly of water, which provides a medium for the organelles to carry out their functions. Therefore, it is reasonable to assume that the cytoplasm contains a high percentage of water. The answer "About 80 percent" suggests that the cytoplasm is predominantly made up of water, while still allowing for some other components to be present.
17.
The structure in a plant cell with chlorophyll is called
Correct Answer
C. Chloroplast
Explanation
The structure in a plant cell with chlorophyll is called a chloroplast. Chloroplasts are responsible for photosynthesis, the process by which plants convert sunlight into energy. They contain chlorophyll, a pigment that gives plants their green color and allows them to absorb light energy. Chloroplasts have a double membrane and contain stacks of membranous structures called thylakoids, where the actual light-dependent reactions of photosynthesis occur.
18.
Which of these living organisms' cells don't have mitochondria?
Correct Answer
D. All of these organisms' cells have mitochondria.
Explanation
All living organisms' cells have mitochondria. Mitochondria are known as the "powerhouses" of the cell because they are responsible for producing energy in the form of ATP through cellular respiration. They are found in the cells of animals, plants, and fungi. Mitochondria have their own DNA and can reproduce independently within the cell. They play a crucial role in various cellular processes and are essential for the survival and functioning of these organisms. Therefore, all of these organisms' cells have mitochondria.