Cell : The Fundamental Unit Of Life - Olympiad Level MCQ, Class 9 Science - Class 9 MCQ

Lysosome is a small vesicle surrounded by a single membrane and contains powerful hydrolytic enzymes. 

Animal cells are typical of the eukaryotic cell, enclosed by a plasma membrane and containing a membrane-bound nucleus and organelles. Unlike the eukaryotic cells of plants and fungi, animal cells do not have a cell wall. This feature was lost in the distant past by the single-celled organisms that gave rise to the kingdom Animalia. Most cells, both animal and plant, range in size between 1 and 100 micrometers and are thus visible only with the aid of a microscope.

 Sunlight is converted to chemical energy in the form of ATP (adenosine triphosphate), which is the main energy-storing molecule in living organisms. ATP is then transported throughout the chloroplast and used to provide the chemical energy necessary to power other metabolic reactions.

Plants absorb water from the soil by osmosis.Root hair cells are adapted for this by having a large surface area to speed up osmosis. The absorbed water is transported through the roots to the rest of the plant where it is used for different purposes: It is a reactant used in photosynthesis.

In animal cell it is plasma membrane, in plant cell it a a double barrier of plasma membrane and cell wall. Nuclear membrane is the barrier between nuclear material and other cell material. Tonoplast is the boundary/outer wall of a vacuole.

Cell Wall

Animal cells do not have a cell wall but have a cell membrane. Plant cells have a cell wall composed of cellulose as well as a cell membrane.

Lysosomes are chemical utilities organelle that is responsible for cleanliness(in simple words)they contain enzymatic juices which can digest many complex substances.Resulting in the food process. and food digest and engulfing many unused and un wanted substances inside the cell.thus keeping it waste free to work properly.

The longest cells in the human body are neurons.
Neurons or the nerve cells form the basic components of the nervous system. A typical neuron possesses a cell body called as soma, hair like structures called as dendrites and an axon. Neurons are specialized in transmitting information throughout the body. Three types of neurons are sensory neurons, motor neurons and interneurons. Neurons possess a membrane that is designed to send information to other cells. Neurons synthesise chemicals called as neurotransmitters which help in transmission of information.

Red blood cells are initially produced in the bone marrow with a nucleus. They then undergo a process known as enucleation in which their nucleus is removed. Enucleation occurs roughly when the cell has reached maturity. 

The absence of a nucleus is an adaptation of the red blood cell for its role. It allows the red blood cell to contain more hemoglobin and, therefore, carry more oxygen molecules. It also allows the cell to have its distinctive bi-concave shape which aids diffusion. This shape would not be possible if the cell had a nucleus in the way. Because of the advantages it gives, it is easy to see why evolution would cause this to occur. However, since little is known about the genes the control enucleation, it is still not a fully understood process.

The major energy currency molecule of the cell, ATP, is evaluated in the context of creationism. This complex molecule is critical for all life from the simplest to the most complex. It is only one of millions of enormously intricate nanomachines that needs to have been designed in order for life to exist on earth. This motor is an excellent example of irreducible complexity because it is necessary in its entirety in order for even the simplest form of life to survive.

Chloroplast is the cell organelle that releases the oxygen  during photosynthesis.

J.E. Purkinje, 1840 observed similar substance in plant cells and coined the term ‘Protoplasm’.

Ribosomes are smallest, membranelese sub- microscopic organelles, called as protein factories. They act as a template, bringing together different components involved in the protein synthesis.

Function of centriole is formation of spindle fibres that separates chromosome during cell division.

The Vacoule is a membrane bound space found in cytoplasm.The vacuole is bound by a single membrane called tonoplast. In plants,the tonoplast faciliates the transport of a no. Of ions and other materials against concentration gradient into the vacuole.

Centrioles are involved in the organization of the mitotic spindle and in the completion of cytokinesis.Centrioles were previously thought to be required for the formation of a mitotic spindle in animal cells.

The Golgi apparatus or Golgi complex is found in most cells. It is another packaging organelle like the endoplasmic reticulum (ER). It was named after Camillo Golgi, an Italian biologist. It is pronounced GOL-JI in the same way you would say squee-gie, as soft a "G" sound. 

Starch grain: a cell inclusion composed of starch; frequently with a characteristic shape for a particular species or group of species. The radiating chain structure of the crystalline residue produces a characteristic 'Maltese Cross' when the grain is viewed between crossed polars in the microscope.

Nucleoplasm has a little different composition. Nucleoplasm can only be found inside of the nucleus. It doesn't have big organelles in suspension. The nucleoplasm is the suspension fluid that holds the cell's chromatin and nucleolus. It is not always present in the nucleus. When the cell divides, the nuclear membrane dissolves and the nucleoplasm is released. After the cell nucleus has reformed, the nucleoplasm fills the space again. 

The nucleus is called the "brain" of the cell because it holds the information needed to conduct most of the cell's functions. Other molecules make proteins from that information on a regular basis - each moment of our lives.

Plant plastids are a group of closely related membrane-bound organelles that carry out many functions. They are responsible for photosynthesis, for storage of products such as starch, and for the synthesis of many types of molecules that are needed as cellular building blocks. Plastids have the ability to change their function between these and other forms. Plastids contain their own DNA and some ribosomes, and scientists think that plastids are descended from photosynthetic bacteria that allowed the first eukaryotes to make oxygen. 

Cell theory is a scientific theory which describes the properties of cells. These cells are the basic unit of structure in all organisms and also the basic unit of reproduction. With continual improvements made to microscopes over time, magnification technology advanced enough to discover cells in the 17th century. This discovery is largely attributed to Robert Hooke, and began the scientific study of cells, also known as cell biology. Over a century later, many debates about cells began amongst scientists. Most of these debates involved the nature of cellular regeneration, and the idea of cells as a fundamental unit of life. Cell theory was eventually formulated in 1839. This is usually credited to Matthias Schleiden and Theodor Schwann. However, many other scientists like Rudolf Virchow contributed to the theory. Cell theory has become the foundation of biology and is the most widely accepted explanation of the function of cells.

The nuclear membrane, also called the nuclear envelope, is a double membrane layer that separates the contents of the nucleus from the rest of the cell. It is found in both animal and plant cells. A cell has many jobs, such as building proteins, converting molecules into energy, and removing waste products. The nuclear envelope protects the cell’s genetic material from the chemical reactions that take place outside the nucleus. It also contains many proteins that are used in organizing DNA and regulating genes.

The lack of a nucleus makes a red blood cell more flexible, and also limits the life of the cell preventing cells "damaged" (e.g. the permanent bond with molecules such as CO) to persist too long in the organism, impairing oxygen distribution.