Flashcards in Cellular Reproduction Deck (52)
How many cells divide each second in the human body?
Millions of cells divide each minute in the human body.
Name three reasons why cells divide and reproduce in the human body.
What are two sub-reasons for replacement as a reason for cells to divide?
Replacement - of lost cells due to a wound or injury
Replacement - of damaged cells
Approximately how many cells are in the grown human body?
Approximately 60 trillion cells are in the grown human body.
What is asexual reproduction?
Asexual reproduction is the creation of offspring by a single parent, without the participation of sperm and egg.
What types of organisms reproduce via asexual reproduction?
Single-celled organisms (ex. Amoeba)
Some multi-cellular organisms (ex. sea-star, spider-plant)
What type of offspring does asexual reproduction produce?
Asexual reproduction produces genetically identical offspring (identical to the parent cell/cells).
Creation of offspring by fertilization of an egg by a sperm.
Division of a single nucleus into two genetically identical "daughter" nuclei.
Give two instances in which cells would use mitosis.
Growth and maintenance
Special type of cell division in which egg and sperm cells are produced.
Name an instance in which meiosis would be used for cell division.
Where are the majority of eukaryotic chromosomes found?
The majority of eukaryotic chromosomes are found in the cell nucleus.
What does a eukaryotic chromosome contain?
Each eukaryotic chromosome contains a very long DNA molecule with thousands of genes.
Discrete units of hereditary information
What are eukaryotic chromosomes made up of?
Eukaryotic chromosomes are made up of chromatin.
Combination of DNA and protein molecules
What functions do proteins do with eukaryotic chromosomes?
Proteins organize chromosomes and help control activity (e.g. histones).
What is interphase?
Interphase is the part of the cell cycle in which there is cell growth, chromosomes are duplicated, and centrosomes emerge.
What percentage of the cell cycle is interphase?
Interphase is 90% of the cell cycle.
Microtubule organizing center
Name the three stages of interphase.
G1 Phase of Interphase
In the G1 phase of interphase, the cellular contents (excluding the chromosomes) are duplicated.
S Phase of Interphase
In the S phase of interphase, each of the 46 chromosomes is duplicated by the cell.
G2 Phase of Interphase
In the G2 phase of interphase, the cell double checks the duplicated chromosomes for error, making any needed repairs.
Name the four stages of mitosis.
When does interphase occur?
Interphase occurs before mitosis.
What occurs in cytokinesis?
Cytoplasm divides during cytokinesis.
When does cytokinesis occur?
Cytokinesis occurs 'after' mitosis.