Cell Cycles Flashcards
What is the result of cell metabolism that can be observed?
Cell growth
Cell metabolism itself is not easily visible, but its effects can be seen in the growth of cells.
What happens when cells reach a certain size?
They split in two
Cells cannot grow indefinitely and must divide to form new cells.
How does growth vary among different organisms and tissues?
It varies widely
Different organisms, organs, and tissues have different rates and patterns of growth.
How often are intestinal cells replaced in adult humans?
Every few days
Intestinal cells have a high turnover rate compared to other cell types.
How often are skin cells replaced in adult humans?
Every few weeks
Skin cells have a moderate turnover rate.
Under what condition do liver cells grow and divide rapidly?
When they are damaged
Liver cells typically do not divide unless necessary for repair.
Do human nerve cells frequently divide?
Seldom
Nerve cells have very limited capacity for division.
What does cell theory state about living things?
All living things are composed of cells
Additionally, cells must arise from other cells.
What is a parent cell often referred to as?
Mother cell
The parent cell divides to form daughter cells.
What are the new cells formed from a parent cell called?
Daughter cells
These cells result from the division of the mother cell.
What is the process of growth, division, and growth called?
Cell cycle
The cell cycle is a regulated process ensuring proper cell numbers and locations.
True or False: The cell cycle is an unregulated process.
False
The cell cycle is a highly regulated process.
Fill in the blank: The cell cycle ensures that organisms have the right number of cells in the right _______.
Places
This includes tissues, organs, and systems.
What are the two types of cell division in eukaryotes capable of sexual reproduction?
Mitosis and meiosis
Mitosis results in identical daughter cells, while meiosis produces specialized sex cells.
What type of cells does mitosis produce?
Identical daughter cells
Mitosis is used by somatic cells to make more body cells.
What are somatic cells?
Body cells
These are the cells that undergo mitosis for growth and repair.
What type of cells does meiosis produce?
Sex cells or gametes
These cells are specialized for sexual reproduction.
What is unique about the chromosome number in gametes produced by meiosis?
They have only half a set of chromosomes
This reduction is essential for maintaining the chromosome number in the resulting organism.
Fill in the blank: Mitosis results in _______ daughter cells.
identical
This is crucial for growth and tissue repair.
True or False: Meiosis results in daughter cells that are identical to the parent cell.
False
Meiosis produces genetically diverse gametes.
What is the role of gametes in sexual reproduction?
To fuse with another gamete to form a new individual
This fusion is essential for the development of a new organism.
What is the primary purpose of mitosis in organisms?
To increase the number of cells, enabling growth and repair of tissues
Mitosis allows organisms to grow from a single cell to a complex multicellular organism.
How do cells in the body constantly renew themselves?
Through mitosis, which replaces lost cells with new ones
This process is particularly evident in the skin and gut.
What is the lifespan of red blood cells, and how are they replaced?
Red blood cells live for four months and are replaced by mitosis
Mitosis ensures a continuous supply of red blood cells.
What role does mitosis play in the growth of organisms?
It allows for growth and the repair of damaged tissues
Mitosis is essential for maintaining healthy tissue.
What is budding in relation to mitosis?
A process where some organisms produce genetically identical offspring through mitosis
This method is notably used by organisms like the hydra.
What type of reproduction do yeast cells utilize?
Asexual reproduction through mitosis
Yeast cells multiply by this method.
Fill in the blank: Mitosis is important for organisms to grow and repair _______.
damaged tissues
True or False: Mitosis is only involved in the growth of multicellular organisms.
False
Mitosis is also involved in asexual reproduction and cell replacement.
What are chromosomes?
Structures made of DNA and proteins that carry hereditary information of cells
Chromosomes are essential for the proper distribution of genetic material during cell division.
What do chromosomes carry?
The DNA code to build all the cell’s proteins
This genetic information is crucial for the functioning and replication of cells.
Where does DNA exist in a cell during interphase?
In the nucleus as a loose mass of DNA threads and proteins called the chromatin network
The chromatin network is less organized and allows for gene expression and replication.
What happens to the chromatin network when a cell prepares to divide?
It condenses, thickens, and becomes visible as short thick chromosomes under a light microscope
This process is essential for ensuring that DNA is accurately divided between daughter cells.
True or False: Chromosomes are only visible during cell division.
True
Chromosomes are not visible in their condensed form during the interphase of the cell cycle.
Fill in the blank: The DNA is packaged in chromosomes so that it can be _______ between each daughter cell.
distributed
Proper distribution of DNA is critical for maintaining genetic integrity in daughter cells.
What is the process of DNA replication?
The process by which DNA in the nucleus is duplicated to ensure each daughter cell receives the same DNA copy as the mother cell.
DNA replication is crucial for cell division and genetic continuity.
What are chromatids?
Identical parts of a replicated chromosome that result from DNA replication.
Each replicated chromosome consists of two chromatids.
What is a replicated chromosome?
A chromosome that consists of two identical parts called chromatids after DNA replication.
The term ‘replicated chromosome’ is used to describe the chromosome post-replication.
What is a centromere?
The structure that visibly joins the two chromatids of each replicated chromosome during cell division.
The centromere plays a key role in the separation of sister chromatids during mitosis.
What are sister chromatids?
The two identical chromatids on a replicated chromosome.
Sister chromatids are separated during mitosis to ensure each daughter cell receives the correct genetic material.
During which phase are sister chromatids separated?
Mitosis.
Mitosis is the process of cell division that results in two identical daughter cells.
What is the main function of the centrosome?
The main microtubule organizing center of the animal cell and a regulator of cell cycles
The centrosome plays a crucial role in maintaining the structure of the cell.
What is the structure of a centrosome?
Made up of two centrioles sitting at right angles to each other
Centrioles are cylindrical structures that are essential for cell division.
What happens to the centriole before cell division?
The centriole duplicates so that each daughter cell receives one
This duplication is critical for the proper functioning of the centrosome in the daughter cells.
What structure does the centrosome organize during cell division?
The spindle apparatus
The spindle apparatus is composed of spindle fibres (microtubules) that help segregate chromosomes.