Final Flashcards
Asexual reproduction
The creation of genetically identical offspring by a single parent, without the participation of sperm and egg
Chromosomes
The structures that contain most of the organism’s DNA
Sexual reproduction
Each offspring inherits a unique combination of genes from its two parents, making a unique combination of traits
Cell division
The reproduction of cells
Binary fission
Dividing in half
The way the prokaryotes (bacteria and archaea) reproduce
Chromatin
How chromosomes exist most of the time
A diffuse mass of long thin fibers
Combination of DNA and protein molecules
Sister chromatids
Contain identical copies of the DNA molecule on a certain chromosome
After a chromosome duplicates, each chromosome in one is called a sister chromatid
Centromere
Joins the two sister chromatids together
Cell cycle
An ordered sequence of events that extends from the time a cell is first formed from a dividing parent cell until its own division into two cells
Growing stage and actual cell division
Interphase
Most of the cell cycle spent here
Cell’s metabolic activity is high, cell performs functions in organism
Increases supply of proteins, creates more cytoplasmic organelles, and grows in size
Chromosomes duplicate
90% of time
G1 S G2
Grows in G1
Synthesizes DNA and duplicates DNA in S
Prepares for cell division in G2
Mitosis phase (M phase)
The part of the cell cycle when the cell actually divides
10% of time
Mitosis and cytokinesis
Mitosis
The nucleus and its contents, including the duplicated chromosomes, divide and are evenly distributed to form two daughter nuclei
Cytokinesis
The cytoplasm is divided in two
Mitosis spindle
A football-shaped structure of microtubules that guides the separation of the two sets of daughter chromosomes
Centrosomes
Clouds of cytoplasmic material that in animal cells contain centrioles
Spindle microtubules come from here
Prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis
Describe
Cleavage furrow
A shallow groove in the cell surface
Cell plate
In a plant when vesicles containing cell wall material fuse
Growth factor
A protein secreted by certain body cells that stimulates other cells to divide
Density-dependent inhibition
Crowded cells stop dividing
Anchorage dependence
Cells must be in contact with a solid surface to divide
Cell cycle control system
A cyclically operating set of molecules in the cell that both triggers and coordinates key events in the cell cycle
Somatic cell
In humans, a typical body cell
A cell that reproduces asexually
Not a sex cell/gamete
