Terms in this set (20)
What is a chromosome?
A chromosome is one long continuous thread of DNA that consists of numerous genes along with regulatory information.
How many chromosomes do our body cells have?
When is DNA loosely organized?
During interphase, or when a cell is not dividing.
What is the key to mitosis?
The association between DNA and protiens.
What are histones?
Any of a group of basic protiens found in chromation.
How many chromosomes does each continuous double-stranded DNA molecule make?
What is a chromatin?
A chromatin is one half of a duplicated chromosome.
What is the centromere?
The region of the condensed chromosomes that looks pinched.
What are telomeres?
The ends of DNA molecules form these structures.
What do telomeres do?
They prevent the ends of chromosomes from accidentally attaching to each other, and they prevent the loss od genes.
What is prophase?
The first stage of mitosis, when chromatin condenses, the nuclear envelope breaks down, the nucleolus disappears, and the centrosomes and centrioles migrate to opposite sides of the cell.
What is anaphase?
The third phase of mitosis during which chromatids seperate and are pulled to opposite sides of the cell.
What is metaphase?
The second phase of mitosis when spindle fibers align the chromosomes along the cell equator.
What is telophase?
The last phase of mitosis when a complete set of identical chromosomes is positioned at each pole of the cell, the nuclear membrane starts to form, the chromosomes begin to uncoil, and the spindle fibers disassemble.
What do the combined processes of mitosis and cytokinesis produce?
They produce two genetically identical daughter cells.
What does cytokinesis do?
Cytokinesis divides the cytoplasm into two cells and completes a full stage of the cell cycle.
What does mitosis do?
Mitosis divides a cell's nucleus into twi nuclei, each with an identical set of DNA.
What happens during interphase?
The cell copies its DNA and grows in preparatio for division.
How many chromosomes does the cell have at the start of mitosis?
What happens to DNA in the early stages mitosis?
The DNA condenses tightly.