Cell Reproduction Flashcards
What is cellular reproduction?
The process by which cells duplicate and divide to create new cells.
How do humans go from a single cell to trillions of cells?
Through cellular reproduction over 10 months.
What is the significance of cellular reproduction in adulthood?
It replaces damaged tissues and heals injuries.
What are the two main types of cellular reproduction?
Asexual reproduction (e.g., binary fission) and sexual reproduction (involving sperm and egg).
According to the cell theory, where do all cells originate from?
All cells originate from preexisting cells.
What is the purpose of cellular reproduction?
Generating new cells and organisms.
What are the two main phases of cellular reproduction?
Growth (duplication of organelles and DNA) and cell division (distribution of contents to daughter cells).
Why is regulation crucial in cellular reproduction?
To prevent uncontrolled cellular reproduction, which can have serious consequences.
What is DNA replication, and when does it occur in the cell cycle?
DNA replication is the process of copying DNA, and it occurs during cell division.
What are chromosomes, and how do they aid in cell division?
Chromosomes are structures in which DNA is packaged, and they help distribute DNA to daughter cells.
What are histones?
Proteins that help package DNA into chromatin.
How does chromatin differ from chromosomes?
Chromatin is a less condensed, thread-like structure of DNA and associated proteins, whereas chromosomes are highly condensed and visible structures.
What is the role of proteins and enzymes in DNA replication and chromosome packaging?
They are responsible for DNA replication and condensing DNA into chromosomes.
What are the key events in cellular reproduction, and in what order do they occur?
Duplication of cell contents and cell division, occurring in an orderly sequence within the cell cycle.
What are the four phases of the cell cycle?
G1, S, G2, and M, with interphase consisting of G1, S, and G2.
What is the role of the G1 phase in the cell cycle?
It is the phase before DNA replication, where the cell decides whether to continue with the cell cycle.
What happens during the S phase of the cell cycle?
DNA synthesis takes place, converting each chromosome from one chromatid to two sister chromatids joined at the centromere.
What is the M phase in the cell cycle, and what occurs during it?
The M phase includes mitosis, where the duplicated nuclear contents are evenly distributed to daughter cells.
How is the cell cycle controlled, and what analogy is often used to explain it?
The cell cycle is controlled by a system that ensures the orderly progression of phases.
What are cell cycle checkpoints, and what is their purpose?
Checkpoints are control points in the cell cycle that ensure that phases occur in order and only proceed when the previous phase is successfully completed.
What is the significance of the G1 checkpoint?
Passing the G1 checkpoint commits the cell to divide, while not passing it can lead the cell to enter G0. It checks for proper growth signals and DNA integrity.
What role does the p53 protein play in the cell cycle?
The p53 protein can stop the cell cycle and initiate DNA repair or apoptosis if DNA is damaged.