Cell Division Quiz Flashcards
What are the three positives of asexual reproduction
Very fast
Energy sufficient
Makes a lot of offspring
Why cell division?
To support bodily function
To heal
To reproduce
To replenish dead cells
What is the negative of asexual reproduction Ct
If it dies all are likely to die too: no variation
What are the three negatives of sexual reproduction
Slow
Not energy sufficient
Fewer offspring
What is the positives of sexual reproduction
Unique: genetic variation
Cell division happens in (what kind of cells)?
Somatic (body) cells and not germ (sex) cells
In eukaryotic cells what are the two main stages of cell division
Mitosis and cytokinesis
Reproduction by mitosis is classified as
Asexual since the cells produced by mitosis are genetically identical to the parent cell
What are chromosomee
In eukaryotic cells the genetic information that is passed on from one generation of cells to the next is carried by chromosomes
What are chromosomes made up of
DNA and proteins
When are chromosomes visible in most cells
During cell division
What are chromatids
Well before cell division, each chromosome is replicated, or copied. Because of this, each chromosome consists of two identical sister chromatids
Each chromatid is attached to an area called the
Centromere
Define centromere
Centromere’s are usually located near the middle of the chromatids, although some line near the ends
Period of growth in between cell divisions is called
Interphase
What occurs during the cell cycle
During the cell cycle the cell grows, prepares for division, and divides to form two daughter cells, each of which then begins the cycle again.
Which phase occurs in the M phase?
Mitosis and cytokinesis
Which phases occur during the S-phase
Chromosome replication or synthesis. When the cell copies of chromosomes it makes a duplicate set of DNA
Which phases are between the M and S phases?
G1 and G2
What are the g1 and g2 phases?
They are actually periods of intense growth and activity
Interphase is divided into three phases:
G1 S and G2
What occurs in the G1 phase
Growth: cells increase in size and synthesize new proteins and organelles
What occurs during the S phase?
Chromosomes are replicated and the synthesis of DNA molecules take place. Key proteins associated with the chromosomes are also synthesize
What happens during the G2 phase
Many organelles and molecules required for Cell division are produced. When it’s completed the cell is ready to enter the M phase and begin the process of cell division
What are the four phases of mitosis
Prophase
Metaphase
Anaphase
Telophase
What are centrioles
Two tiny structures located in the cytoplasm near the nuclear envelope at the beginning of prophase
What is the spindle
A fanlike microtubule that helps separate the chromosomes
Define prophase
The chromatin condenses into chromosomes. The centrioles separate, and a spindle begins to form. The nuclear envelope breaks down
Define metaphase
The chromosomes line up across the center of the cell. Each chromosome is connected to a spindle fiber at its centromere
Define anaphase
The sister chromatids separate into individual chromosomes and are moved apart
Define telophase
The chromosomes gather at opposite ends of the cell and lose their distinct shapes. 2 new nuclear envelopes will form
Define cytokinesis
The cytoplasm pinches in half. Each daughter cell has not dental set of duplicate chromosomes
How does cytokinesis occur in most animal cells
The cell membrane is drawn in word into the cytoplasm is pinched into two nearly equal parts
What forms midway between the divided nucleus during cytokinesis in plant cells
A structure known as the cell plate
Mitosis is division of the
Nuclei
