Concept 3 Flashcards
What is the order of events from egg to sperm to embryo?
Once an egg is fertilized by sperm it goes through cell division repeatedly until it grows and divides into an embryo. The cell division happens through Mitosis and differentiation, Mitosis is cells dividing into identical cells and differentiation is when cells divide into special cells that can conduct special functions.
What are stem cells?
Undifferentiated cells that eventually become differentiated and can become specialized cells
What are specialized cells?
Cells that have special structures that let them do special functions, they are differentiated.
What is the level of organization that goes from cell to organisms from differentiation?
Cell → Tissue → Organ → Organ System → Organism
What is interphase?
the growth phase of the cell cycle
What goes on during G1?
The cell grows and makes proteins
What happens during S phase?
DNA replication occurs, doubling the number of chromosomes
What happens during G2 phase?
More cell growth and protein synthesis
What is mitosis?
The division phase of the cell cycle
What happens during prophase?
The nuclear membrane disappears and chromosomes spread out and spindle fibers form from centrioles
What happens during metaphase?
Spindle fibers connect to the centromere and chromosomes lineup in the middle of the cell
What happens during Anaphase?
Sister chromatids separate and pull away from eachother, becoming individual. and chromatids move to opposite ends of the cell
What happens during Telophase?
Chromosomes decondense and strata to look like chromatids again and the nuclear membrane reforms around chromosomes at each pole.
What happens during Cytokinesis?
The final phase where the cytoplasm divides and creates to individual cells
When does a cell know when it needs to divide?
Every cell divides at a different rate based on its need. Cells that wear and tear more replace faster
What is external regulation?
Signals that come from outside of the cell, Ex: hormones and nutrients.
What is internal regulation?
Signals that come from the cell’s when nucleus. Ex: DNA from inside the cell
What are checkpoints?
They are “stop” and “go” signals that regulate the cycle
What is apoptosis?
Programmed cell death, internal/external signals activation genes that produce self destructive enzymes.
When does a cell go into apoptosis?
When something is wrong with the cell, a mutation
Define tumor
Clump of cells that divide uncontrollably
What is a begin tumor?
Abnormal cells that typically remain clustered together , they are mostly harmless and are easy to remove
What is a malignant tumor?
Cancer cells rarely break away from the t humor and move to other parts of the body, which creates more tumors.
What are some of the several causes of cancer?
Biological factors
Age
Inherited genetic factors
Skin type
Diet and physical activity
UV radiation
Viruses that can cause other infections
Exposure to carcinogens. Ex: tobacco smoke, asbestos, ect.
What is differentiation?
A process that creates special structures and functions
What are stem cells?
Undifferentiated cells that become differentiated and can become any type of cell.
What is the cell cycle?
A repeated pattern of growth, DNA duplication and cell division that occurs only in Eukaryotic cells.
What is a chromosome?
One long continuous thread of DNA that consist of thousands of genes and regulatory information
What is a gene?
A section of DNA with the instructions for making a protein
What are sister chromatids?
Two identical chromatids
What is the centromere?
Region of the condensed chromosomes. that looks pinched
What is the telomere?
The ends of the DNA molecule
What is cancer?
Uncontrolled cell division
What is metastasize?
Spreading of disease from one organ to another
What are carcinogens?
Cancer causing agents’ chemicals that cause cancer by mutating DNA/
