cell cycle
why do cells need to divide?
To repair damaged tissues, replace damaged worn out cells, immunity,growth,reproduction,keep surface are to volume ratio large
What is mitosis?
The division of the nucleus into two nuclei.Each nuclei has a complete set of chromosomes identical to the parent cell.
what happens during interphase?
The cell copies its DNA in preparation for mitosis.
what does the cell membrane do during the cell cycle?
It separates the cytoplasm from its surrounding environment.It only lets certain molecules enter and exit.
do you grow by increasing number of cells or cells enlarging?
Increasing the number of cells.
what is the cell cycle?
A regular sequence of cell growth,DNA replication, division.
What are the 4 stages of mitosis?
prophase, metaphase,anaphase,telophase.
what is the last phase of the cell cycle?
cytokinesis
what is a centromere and what does it do?
The centromere is the point at which two chromatids are connected.It is responsible for the movement of the replicated chromosomes into the two daughter cells during mitosis and meiosis.
what factors limit cell size and why?
Diffusion because as the cell gets too big the surface area to volume ratio gets smaller making diffusion inefficient.
What are the main stages of the cell cycle?
Interphase,mitosis,cytokinesis.
what happens during prophase?
In prophase, chromosomes condense into chromatid.centrioles move into opposite sides of the cell.spindle fibers form a bridge between centrioles nuclear membrane and nucleolus break down.
what happens during telophase ?
Each set of chromosomes are made a new nuclear membrane and nucleolus.The spindle fibers break down chromosomes start to uncoil.
What is the role of the nucleus in cell division?
The main function of the cell nucleus is to control gene expression and meditate the replication of DNA during the cell cycle.
Do cells have the same length to their cell cycle?
No,each cell has a different length to their cell cycle.
90% of the cells life is spent in...
Interphase
what happens during metaphase?
In metaphase, Each chromatid attaches to a spindle fiber at the centromere.The chromatids are pulled up to line at the center of the cell.
what is cytokinesis?
The division of the cytoplasm and distribution of structures.Starts during telophase.When completed each identical daughter cell enters interphase and a new cell cycle begins.
what is the role of spindle fibers during cell division?
The spindle fibers form a bridge in metaphase the spindle fibers attach to the chromosomes and in anaphase the spindle fibers pull the chromatid in opposite directions.
what are centrioles?
Cylindrical organelle that is near the nucleus in animal cells, in pairs involved in the development of spindle fibers in cell division.
What is chromatid?
During DNA replication, the cell makes an exact copy of the chromosomes.During prophase of mitosis, the chromosomes coil into the dense rods and can be seen.
What happens during anaphase?
During this phase, Chromatids are pulled from the spindle fibers at the centromere into the individual chromosomes.The spindle fibers move each set of chromosomes towards opposite ends.
how is cytokinesis different in animal cell than in the plant cell?
Their main difference is how they form the daughter cells during cytokinesis.During that stage animal cells form furrow or cleavage that goes way to formation of daughter cells.Due to the existence of the rigid cell wall, plant cells don't form furrows.
Summarize what happens to chromosomes during the stage of the cell cycle in which the nucleus divides.Include the terms prophase, metaphase,anaphase,and telophase.
In interphase the cell grows and makes a copy of the DNA,in prophase the centrioles move to opposite sides of the nucleus,In metaphase the chromosomes line up in the centerline anaphase the chromatids separate and in telophase the chromosomes stretch and a new nuclear envelope is formed.
what is an end result of the cell cycle?
At the end of the cell cycle, two distinct daughter cells are produced. Each cell contains identical genetic material. The time it takes for a cell to complete one cell cycle varies depending on the type of cell .