study guide - unit two concept 3 Flashcards
Differentiation
A process that creates special structures and functions
Stem cells
Undifferentiated cells that can become differentiated into one or more types of specialized cells
Gastrula
Embryo with 3 differentiated germ layers
Organogenesis
The process of body organ and organ system formation
Cell Cycle
A repeated pattern of growth, DNA duplication, and cell division that occurs in eukaryotic cells
Chromosome
One long continuous thread of DNA that consists of thousands of genes and regulatory information.
Gene
A section of DNA with instructions for making a protein
Sister Chromatids
Two identical chromatids (halves of a duplicated chromosome)
Centromere
Region of the condensed chromosomes that looks pinched
Telomere
Ends of the DNA molecule
Cancer
Uncontrolled cell division
Metasize
Spreading of disease from one organ to others
Carcinogens
Cancer causing agents
Summarize the order of events from egg and sperm to embryo.
The male sperm travels to the female egg to fertilize it
The resulting zygote has all of its chromosomes for the first time.
It begins to go through mitosis, repeatedly making identical cells.
That clump of identical cells eventually starts to go through differentiation, and the resulting specialized cells organize into the tissues, organs, and organ systems that make up the embryo.
Explain the difference between specialized cells and stem cells.
Stem cells are undifferentiated and can become any type of cell,
whereas specialized already have specific structures and thus functions.
List the levels of organization from cell to organism that result from differentiation.
Cell 🡪 tissues 🡪 organs 🡪 organ systems 🡪 organism
List the two main purposes for cell division.
Growth and repair.
Sketch and label a homologous chromosome pair before and after S phase. Include a brief description of the importance of S phase.
During the S phase of Interphase DNA replication occurs, doubling the DNA. This is critical so that when the cell divides, each resulting daughter cell has a complete set of chromosomes.
Draw it too
interphase
the growth phase of the cell
G1: Gap 1 Phase: cell grows and makes proteins
S: Synthesis Phase: DNA Replication occurs, doubling the number of chromosomes
G2: Gap 2 Phase: more cell growth and protein synthesis
draw
Prophase
-chromosomes condense and become sister chromatids (in X’s)
-nuclear membrane disappears
-spindle fibers form out of centrioles
-know drawing
Metaphase
-spindle fibers connect to the centromere of each sister chromatid
-chromosomes line up in the middle of the cell
Anaphase
-sister chromatids separate, pulling away from each other and becoming individual chromosomes
-chromatids move to opposite ends of the cell
Telophase
-chromosomes decondense and start to look like chromatin again
-nuclear membrane reforms around chromosomes at each pole
-spindle fibers break down
-cytokinesis begins at the end of telophase
Cytokenesis
the division of the cytoplasm into 2 individual cells
END RESULT: 2 identical body cells
Differentiate between cytokinesis in plant and animal cells
In plant cells- cell plate forms midway between divided nuclei and gradually develops into a cell wall.
In animal cells- forms cleavage furrows that pinches the cell into two equal parts
Differentiate between cytokinesis in plant and animal cells
Plant cells form a cell plate, while animal cells form a cleavage furrow.
Summarize how cells know when they need to divide. Include examples of the difference between internal and external regulation.
They utilize a chemical control system that responds to internal (from cell’s own DNA) signals and external (hormones, nutrients, etc.) signals.
Explain the key roles of checkpoints and apoptosis in the regulation of the cell cycle.
Checkpoints are critical points were “stop” and “go” signals regulate if the cycle will proceed.
Apoptosis is programmed cell death that can be utilized to destroy damaged cells before they divide.
Define tumor and differentiate between the two types.
Tumor = clump of cancerous cells that divides uncontrollably.
Benign tumors are clustered together, malignant tumors have metastasized and spread to other tissues and organs.
List several potential causes of cancer.
Biological factors (like age and inherited mutations)
Lifestyle choices (like diet and physical activity)
Viruses (like HPV)
Carcinogens (like tobacco smoke)
