Cell And Tissues Flashcards
Histology; AKA microanatomy
the study of microscopic structure and function of cells and associated tissue
Cell
the smallest living unit of organization in the body
Tissue
Cells with similar characteristics of form and function are grouped together
Organ
Various tissue types are bonded together to form a somewhat independent body part that performs a specific function(s)
A collection of tissues made of similarly specialized cells
System
Organs functioning together
cellular division
Cells in a tissue undergo cellular division to reproduce themselves and replace dead tissue cells as a result of this division process, two daughter cells are formed which are identical to each other and identical to the original parent cell
Exocytosis
Active transport of material from a vesicle within the cell out into the extracellular environment
Cells are surrounded by a____ that consists predominantly of____
cell membrane (or plasma membrane); phospholipids and proteins
Phospholipids in the cell membrane serve as the_____because they_____
diffusion regulators; selectively allow certain molecules to pass through based on their size, charge, and polarity. Overall, they control movement of substances into and out of the cell, thus maintaining the cell’s internal environment
Cytoplasm
• Semifluid part contained within the cell membrane boundary
• Also includes the cytoskeleton, which provides a skeletal system of support
• Contains a number of structures called organelles
• Also contains spaces or cavities called vacuoles
Organelles
• Metabolically active specialized structures within the cell in the cytoplasm
• Allows each cell to function according to its genetic code
Vacuoles
Spaces or cavities within the cytoplasm inside the cell
Nucleus (plural, nuclei)
Largest, densest, most conspicuous organelle in the cell when viewed microscopically. The nucleus is the cell’s “data bank” because it stores the genetic code. It is also the “command center” of the cell, controlling the other organelles in the cell and is influenced by what occurs inside the cell as well as outside the cell
Primary nucleic acid in the nuceloplasm is___
deoxyribonucleic acid (DNA), in the form of chromatin
The nucleus of a cell looks like____ when viewed at lower-power microscopically
diffuse stippling
_____in the nucleus give directions for everything the cell is and will become and controls all functions the cell performs
DNA and ribonucleic acid (RNA)
Deocyribonucleic Acid (DNA)
The hereditary material in humans and almost all other organisms mostly located in the cell nucleus (where it is called nuclear DNA with a small amount found in the mitochondria where it is called mitochondrial DNA (mtDNA). Nearly every cell in a person’s body has the same DNA
The information in DNA is stored as a code made up of four chemical bases:
• Adenine (A), Guanine (G), Cytosine (C), Thymine (T)
In an actively dividing cell, chromatin _____
condenses into rodlike chromosomes.
In the nucleus, three very important types of RNA are produced:
messenger RNA (mRNA) molecules, which are complementary copies of distinct segments of DNA;
transfer RNA (tRNA) molecules, which are capable of specifically binding to and transporting amino acid units for protein synthesis;
ribosomal RNA (rRNA) molecules
centromere
A clear, constricted area near the middle of every chromosome. Chromosomes become two filamentous (threadlike) chromatids (or sister chromosomes) joined by one centromere during cell division.
during cell division Sister chromatids remain attached at the_____.these sister chromatids eventually will_____ during cell division and become____
centromere; separate; individual “daughter chromosomes” that are distributed to the newly formed daughter cells, ensuring each new cell receives a complete set of genetic information
DNA replication is the process where___
a cell duplicates its DNA, creating two identical copies of each chromosome, which are called “sister chromatids”
Neoplasm
The fluid part within the nucleus that contains molecules used in the construction of ribosomes, nucleic acids, and other nuclear materials