Cell divison Flashcards
What is a chromosome?
A protein found in the nucleus of eukaryotic cells, which is a coiled thread-like structure of nucleic acids (DNA)
What are genes?
Sections of DNA that contain the code for a particular protein.
In what arrangement are chromosomes found normally?
Pairs
How many chromosomes does a human have in each cell?
23 pairs OR 46 in total.
What has to happen within the cell before Mitosis? (2 steps)
- Cell organelles (e.g. mitochondria and ribosomes) have to replicate
- Chromosomes have to be replicated (copied).
How many chromosomes will be present in a cell after DNA replication?
92 OR 46 pairs.
What occurs during cytokinesis (the final stage)?
The cytoplasm and cell membranes divide. Two daughter cells are created.
Mitosis is critical for….
growth, replacement and development of an organism.
What is a stem cell?
Cells that have not undergone differentiation. aka. an undifferentiated cell.
Describe the function of stem cells in embryos.
To develop into multiple cell types. So that the embryo can develop into a mature organism.
Describe the function of stem cells in plant meristems.
To allow a plant to keep growing throughout its life (animals stop growing when mature) by specialising into any type of cell.
What is a potential use of stem cells in medicine?
To treat conditions where cells have been damaged e.g. diabetes, paralysis.
Give an advantage of therapeutic cloning.
No rejection of the new cells by the patient (as they are the patient’s own genetic make-up).
Give two potential problems with therapeutic cloning.
- Risk of viral infection
- Religious/ethical objections around the use of embryos.
How are plant stem cells used in horticulture (commercial plant growing)?
To create plant cuttings (clones of the original plant).