Biology : Cells and Control Flashcards
(88 cards)
What do chromosomes contain?
Genetic Information
What are chromosomes?
Coiled up lengths of DNA molecules
How many copies of chromosomes do body cells usually have?
Two
If there are two copies of a chromosome, what does that make the cells?
Diploid cells
Are the two cells created by mitosis identical or not?
Identical
Do the nucleus of each of the two cells contain the same number of chromosomes or not?
They do
What is the process in which body cells divide to produce new cells called?
The Cell Cycle
What is the stage of the Cell Cycle called when the cell actually divides?
Mitosis
What do multicellular organisms use mitosis for?
To grow or replace (damaged) cells
What do some other organisms use mitosis for?
Asexual reproduction
What is the first stage of the Cell Cycle?
Interphase
What happens in Interphase?
The cell grows and increases the number of subcellular structures (mitochondria, ribosomes). After which, it duplicates the DNA, to form a ‘x’-shaped chromosome, where each arm of the chromosome is exactly the same
What is the second stage of the Cell Cycle?
Prophase
What happens in Prophase?
Chromosomes condense, getting shorter and fatter
Membrane around nucleus breaks down, chromosomes lie free in cytoplasm
What is the third stage in the Cell Cycle?
Metaphase
What happens in Metaphase?
Chromosomes line up in the centre of the cell
What is the fourth stage of the Cell Cycle?
Anaphase
What happens in Anaphase?
Spindle fibres pull the chromosomes apart
Chromatids are pulled to opposite ends of the cell
What is the fifth stage of the Cell Cycle?
Telophase
What happens in Telophase?
Membranes form around each set of chromosome
These become the nuclei of the new cell
The nucleus has divided
When does Cytokinesis occur?
Before Telophase ends
What happen in Cytokinesis?
The cytoplasm and cell membrane divide to form two separate cells
What is produced at the end of mitosis?
Two new daughter cells
What are the two genetically identical daughter cells also genetically identical to?
The parent cell