Cells Flashcards
What are the two types of cell division?
mitosis and meiosis
What is created through mitosis?
2 genetically identical daughter cells, they have the same number of chromosomes as the parent cell
What is created through meiosis?
4 genetically unique daughter cells, they each have half the number of chromosomes as the parent cell
List the 3 stages of the cell cycle
Mitosis, Interphase: (G1, synthesis, G2), Cytokinesis
What is interphase?
growth stages (most of the cell cycle) ie G1, synthesis, G2
Describe what happens to a cell in interphase
DNA unravels + replicates, organelles replicate + ATP increases
What is mitosis?
the formation of two new identical daughter cells from an original parent cell
Why is mitosis necessary?
it replaces damaged or old cells and is how organisms grow and repair, it is a form of asexual reproduction
What is cytokinesis?
final stage of mitosis where the 2 joined cells separate into 2 daughter cells
What type of cells undergo mitosis?
body cells that are unspecialised or retain the ability to divide
Describe 3 uses of mitosis by organisms
for growth and repair of human cells (e.g. skin), embryonic development, asexual reproduction of plants
List the stages of mitosis in order
prophase, metaphase, anaphase, telophase
What is a centromere?
the centre point of a chromosome- holds 2 sister chromatids together
What is a centriole?
bundles of protein, which produce spindle fibres and move to poles of the cell in prophase
Describe what occurs in prophase
nuclear envelope breaks down, centrioles move to either end, chromosomes condense
Describe what occurs in metaphase
chromosomes line up on the spindle equator, spindle fibres attach to centromeres
Describe what occurs in anaphase
no nuclear envelope, v-shaped chromatids being pulled apart to opposite ends of the cell
Describe what occurs in telophase
chromatids uncoil and nuclear envelope reforms
If 10 cells out of 100 are in metaphase and one cycle takes 15 hours, how long (in minutes) do the cells spend in metaphase?
15x60=900, (10/100)x900= 90 mins
What causes cancer? (simplified)
when the cell cycle is out of contol (gene mutation)
How are tumours linked to cell division?
tumours are caused by uncontrolled cell division
What is the name given to the different types of tumour?
benign (non cancerous) and malignant (cancerous)
What is the basic difference between a benign and a malignant tumour?
a benign tumour grows slowly and is kept in one place, not typically life threatening, a malignant tumour grows quickly and will spread around the body, more likely to be life threatening
What affects the rate of cell division?
the environment, growth factors and 2 genes
What happens if the genes controlling cell division are damaged (mutated)?
uncontrolled mitosis can occur
If uncontrolled mitosis due to mutation occurs, how does this affect the cells being created?
they are usually structurally and functionally different to normal body cells, typically they die or are destroyed
If the damaged cells that created the genetic mutation survive, what could happen?
the could clone themselves and form either benign or malignant tumours
Vincristine is a cancer drug which prevents spindle fibres from forming, describe how this will treat the tumour
no spindle = no anaphase so mitosis cannot occur, cells can’t divide + cancer can’t develop further
What are the inner folds of mitochondria called?
cristae
what is the function of the golgi apparatus?
to process and package new proteins and lipids; makes lysosomes
What is the function of a lysosome?
contains enzymes- lysozymes used to digest broken/ invaded cells (pathogens)
What is the function of a ribosome?
protein synthesis
