LAB2. Cytology Flashcards
Cell came from comes from the Latin word __________ which means small rooms
cella
Unit of structure and function of living things
Cell
3 basic parts of eukaryotic cell:
- Cell/plasma membrane
- Cytoplasm/Protoplasm
- Nucleus
it is where genetic information is stored which is marked by the presence of DNA
Chromosome
cell structure that surrounds the nucleus
Nuclear membrane
spherical in shape, it is only present when the cell is not actively dividing
Nucleus
it contains RNA which is needed for protein synthesis
Nucleolus
these are cylindrical pairs of organelles located near the nucleus which are composed of 9 tubes and 3 tubules
Centrioles
cell structures normally found in plant cells, it contains green chlorophyll
Chloroplasts
composed of microtubules, it supports the cell by providing shape and structure
Cytoskeleton
serving as the cell’s transport system, it is classified into two types according to
the presence and absence of ribosomes
Endoplasmic reticulum
2 types of ER
- Rough endoplasmic reticulum
- Smooth endoplasmic reticulum
Type of ER – absence of ribosomes
Smooth endoplasmic reticulum
Type of ER - presence of ribosomes
Rough endoplasmic reticulum
flattened structures/membrane located near the nucleus, temporary storage of protein synthesized
Golgi apparatus
these are membrane-bound sacs that function for storage, digestion and waste removal
Vacuoles
sac-like structures that are responsible for the removal and/or transport of undigested materials
contain digestive enzymes for breaking down of proteins, lipids and NA, also
involved in the removal of waste molecules, as well as recycling of molecular subunits
Lysosome
rod-shaped organelles, “powerhouse”,
where energy producing chemical reaction takes place (site of ATP
synthesis)
it recycles and decomposes proteins, fats and carbohydrates while forming
urea
Mitochondria
composed of RNA and proteins, “cell factories”, responsible for the synthesis of
protein molecules
Ribosomes
2 types of Ribosomes
- Stationary Ribosomes
- Mobile Ribosomes
Ribosomes classified according to their location
__________ these are embedded in the endoplasmic reticulum
Stationary ribosomes
Ribosomes classified according to their location
__________ these are found directly in the cytoplasm
Mobile ribosomes
fluid matrix, semisolid in nature, found within the cell, but outside the nucleus,
where all the organelles are suspended
Cytoplasm/Protoplasm/Cytosol
complex, highly organized structure that defines the shape of the plant cell (fungi, algae and even bacteria)
it controls turgidity
Cell wall
it is the outer membrane of cells that controls cellular traffic
it contains proteins that are surrounded by a phospholipid layer
Cell/Cytoplasmic/Plasma membrane
What are the differences between an animal cell and a plant cell?
- Cell Wall: Plant cells have a rigid cell wall composed of cellulose, hemicellulose, and lignin, providing structural support and protection. Animal cells lack a cell wall and instead have a flexible cell membrane.
- Chloroplasts: Plant cells contain chloroplasts, specialized organelles that facilitate photosynthesis. Chloroplasts contain chlorophyll, which enables plants to convert sunlight into energy. Animal cells do not have chloroplasts.
- Vacuoles: Plant cells typically have a large central vacuole that occupies a significant portion of the cell’s interior. The vacuole helps maintain cell shape, store water, nutrients, and waste products, and contributes to turgor pressure. Animal cells may have small vacuoles, but they are generally less prominent.
- Shape and Size: Animal cells come in various shapes and sizes depending on their function. They can be round, irregular, or elongated. Plant cells tend to have a fixed shape due to the rigid cell wall, and they are often rectangular or square-shaped.
- Lysosomes: Animal cells commonly contain lysosomes, which are membrane-bound organelles involved in intracellular digestion and waste removal. Lysosomes contain enzymes that break down various substances. Plant cells typically have fewer lysosomes or may lack them altogether.
__________ is a fundamental concept in biology that describes the basic unit of structure and function in living organisms.
Cell theory
Cell Theory Principles (3)
- All living organisms are composed of one or more cells.
- The cell is the basic structural and functional unit of life.
- Cells arise from pre-existing cells through cell division.
The cell theory is credited to three key scientists:
Matthias Schleiden (1804-1881): Schleiden, a German botanist, contributed to the cell theory by observing plant tissues under a microscope. In 1838, he concluded that plants are composed of cells and that the cell is the basic unit of plant structure.
Theodor Schwann (1810-1882): Schwann, a German physiologist, made significant contributions to the cell theory through his research on animal tissues. In 1839, he concluded that animal tissues are also composed of cells, extending the cell theory beyond plants.
Rudolf Virchow (1821-1902): Virchow, a German physician and pathologist, added another important principle to the cell theory. In 1855, he proposed that cells arise from pre-existing cells through cell division. This concept, known as the principle of biogenesis, completed the cell theory by explaining the origin and continuity of cells.
__________ is the principle or concept that living organisms can only arise from pre-existing living organisms.
Biogenesis
Principle behind biogenesis
The principle of biogenesis states that life can only be produced by other living organisms through processes such as reproduction or cell division. This principle is a fundamental aspect of modern biology and is supported by extensive experimental evidence.
Who is the person who coined the term biogenesis?
Henry Charlton Bastian
__________ belief that living organisms could arise spontaneously from non-living matter.
Theory of Spontaneous Generation
