Module 9 - Cellular Reproduction and Sexual Reproduction Flashcards
Why do cells stay small?
Ratio of surface area to volume
transport of substances
cellular communication
What is chromatin?
The relaxed form of DNA
What are chromosomes?
Condensed structures that contain the DNA and are visible during mitosis
What is a nucleosome?
A unit inside a chromosome, consisting of DNA wrapped around histone proteins.
What is the cell cycle?
The cycle by which cells reproduce.
What is interphase?
The stage during which the cell grows, develops into a mature functioning cell, duplicates the DNA in its nucleus and prepares for division.
What phase does a cell spend most of its life in?
Interphase
What are the substages of interphase?
Gap 1, Synthesis, and Gap 2
What happens during gap 1?
The phase right after splitting. A cell is growing, carrying out normal functions, and preparing to replicate DNA.
What happens during synthesis?
The cell copies its DNA in preparation for cell division
What happens during gap 2?
The cell prepares for division, a protein that makes microtubules is synthesized, the cell takes inventory
What is mitosis?
The stage of the cell cycle during which the cells nucleus and nuclear materiial divide.
What are the stages of mitosis?
Prophase
metaphase
anaphase
telophase
What are sister chromatids?
Structures that contain identical copies of DNA, the halves of a chromosome.
What is a centromere?
The structure at the center of the chromosome where the sister chromatids are attached.
What happens during prophase?
Nuclear membrane disintegrates
Nucleolus disappears
Chromosomes condense
Spindle apparatus begins to form between the poles
What is the spindle apparatus?
A structure including spindle fibers, centrioles, and aster fibers. Moves chromosomes in cell division.
What happens during metaphase?
Chromosomes attach to spindle apparatus and align along equator of cell.
What happens during anaphase?
Chromatids are pulled apart, resulting in the separation of replicated DNA. Microtubules of spindle apparatus shorten.
What happens during telophase?
Chromosomes arrive at the poles of the cell and begin to relax and decondense. Two new nuclei are formed and nucleoli reappear.
What is cytokinesis?
The final stage of the cell cycle, where a cell’s cytoplasm divides and the cells completely separate.
What are cyclins?
Proteins that bind to enzymes in interphase and mitosis to initiate the various activities that take place in the cell cycle.
What are the enzymes that cyclins bind to called?
Cyclin-dependent kinases (CDKs)
What are quality control checkpoints?
They are built-in checkpoints that monitor the cycle and can stop it if something goes wrong.
What is checked at the quality control checkpoints?
Is the DNA damaged?
Is the DNA replicating correctly?
Has all DNA been replicated?
Are chromosomes properly attached to spindles?
What is apoptosis?
Programmed cell death when a cell can’t pass the checkpoints.
What is cancer?
The uncontrolled growth and division of cells; a failure in the regulation of the cell cycle.
What are carcinogens?
Substances and agents that are known to cause cancer
What are genes?
Regions of DNA that code for the formation of proteins.
What are homologous chromosomes?
A chromosomes that make up a pair; one from each parent.
What are gametes?
Sex cells that have half the number of chromosomes. (human gametes have 23)
What is fertilization?
The process by which one gamete combines with another gamete
