Modern Cell Theory and History

English scientist who observed tiny, hollow, room-like structures in cork under a microscope, calling them 'cells' due to their resemblance to monks' rooms.

Dutch scientist who used a simple microscope to observe living cells in blood, rainwater, and teeth scrapings, some of which were later called bacteria.

German botanist known for his discovery that plant parts are composed of cells.

German zoologist who extended Schleiden's findings by showing that animal parts are also made of cells.

German physician who proposed that all living cells originate from existing cells.

Anaximander was a Greek philosopher who lived in the 6th century B.C. He is credited with proposing early ideas about evolution, suggesting that life originated in the sea and transitioned to land.

Plato, a philosopher, did not directly contribute to biological discoveries. His focus was philosophical instead of experimental. However, many of his students went on to make significant contributions to the field of classification.

Democritus, a prominent Atomist philosopher, believed that everything is made up of tiny, indivisible particles called atoms. This concept, known as atomic theory, has a strong connection to biology. One of his core beliefs was that nothing can be created from nothing.

Aristotle, a Greek philosopher known for his experimental approach, dissected animals to study their structure and classify them. He sought to understand the connection between the body and the soul. Many of his animal classifications are still used today. He also predicted Mendelian genetics by suggesting that offspring inherit traits from their parents.

The invention of the microscope revolutionized biology by providing a tool to study the cellular world, which was previously invisible to the naked eye. This technology opened doors to understand the fundamental building blocks of life.

Galileo Galilei, a prominent scientist with diverse contributions, is credited with the invention of the microscope.

The neuron theory states that the nervous system is composed of individual cells called neurons. This theory was definitively proven with the advent of the electron microscope, which allowed scientists to observe the intricate structure of neurons and their connections called synapses.

The phase of the cell cycle where the cell divides its nucleus and cytoplasm, resulting in two daughter cells.

This is the first stage of mitosis, where the chromosomes begin to condense and become visible as sister chromatids attached by the centromere. The nuclear envelope, golgi, ER, and nucleolus start to disappear.

During this stage, the condensed chromosomes align at the center of the cell, forming a plane called the metaphase plate. This alignment is driven by the attachment of spindle fibers to the kinetochores on the centromeres of the chromosomes.

Sister chromatids, attached by the centromeres, separate and move towards opposite poles of the cell, pulled by the shortening spindle fibers.

The final stage of nuclear division, where the chromosomes reach opposite poles and decondense. The nuclear envelope, nucleolus, golgi, and ER reform around each set of chromosomes.

The division of the cytoplasm into two daughter cells. In animal cells, this is achieved through a furrow in the plasma membrane that gradually deepens and joins the center, separating the cytoplasm.

These are the spindle fibers attached to the centromeres of the chromosomes during mitosis. They pull the sister chromatids apart during anaphase.

The structure that holds together the two sister chromatids during mitosis. It is also the point of attachment for the spindle fibers during cell division.

A structure that helps organize the microtubules during mitosis. These structures migrate towards the poles of the cell, helping to create the spindle fibers.

A defining characteristic of non-living things is that they don't possess life. They don't exhibit any signs of life, such as growth, reproduction, or movement.

Unlike living organisms, non-living things do not consist of cells. They lack the fundamental building blocks of life - cells.

Because non-living things lack cells, they also lack protoplasm, the living substance found inside cells. This means they are incapable of carrying out metabolic activities.

Non-living things do not have a fixed size. They can take on the shape of their container or environment. For example, a liquid takes the shape of its container, and rocks can be molded by erosion.

The change in the state or form of a non-living thing is caused by an external influence. For example, a snowball melts due to heat.

Non-living things grow by adding material externally. For example, a snowball gets bigger when more snow sticks to it.

Non-living things do not have a lifespan and therefore cannot die. They do not have cells with a finite life cycle.

Non-living things do not reproduce. They lack the ability to create new individuals of the same type.

Non-living things do not exhibit any life processes, such as nutrition, excretion, or respiration. They do not require food, air, or water to survive.