Cell division Flashcards
What are gametes
Sex cells eg sperm, ova, pollen
What are haploid cells
Describes a cell or nucleus of a gamete that has unpaired set of chromosomes so half the normal number
What are diploid cells
Describes a cell or nucleus that has paired sets of chromosomes
What’s a gene
A section of a chromosome made from Dna that carries the code to make a protein
What are alleles
Two versions of the same gene - one from your mum and one from your dad
What type of cell are gamete
Haploid cells
What are most cells in your body like
Contain 2 sets of DNA and are so diploid
What is DNA
Coiled into chromosomes, humans have 23 pairs (46 total) chromosomes in a diploid cell
What about animal chromosome numbers
They are can be different to humans
How is a chromosome divided
Into genes - each gene carries genetic info to make a protein and therefore make a characteristic
You have 2 copies of each gene (one from each parent) which are alleles
What are chromosomes like
Long and thin - they have a point towards the middle where they appear to pinch inwards where no genes are present called the centrometre
What’s mitosis
Cell replication that produces two identical copies of a diploid cell
What are daughter cells
Cells produced during mitosis
What’s a chromatid
A copy of a chromosome during cell division
What’s cytokinesis
The final part of the cell cycle after mitosis in which the cell splits in to two, new nuclei formed
What’s the interphase
The active life of a cell during which the cell prepares for mitosis
What does mitosis do
Make cells to replace dead cell and make cells for growth
Is there genetic variation in mitosis
No mother and daughter cell are identical
tell me about the prophase
The nucleus disappears, the chromosomes shorten and fatten, chromosomes make copies of them selves
Tell me about metaphase
Chromosomes and chromatids line up in centre of cell
Tell me about anaphase
Chromosomes pulled to opposite side of cell chromatids are
Tell me about the telophase
Cell membrane starts to pinch inwards
What’s a stem cell
An undifferentiated cell that can develop into more that one/ one type of specialised cell
What’s differentiate
To specialise or adapt to a specific function
What’s the meristem
An area of a plant in which rapid cell division occurs and stem cells are found, normally in the tip of roots and shoots
What’s a hormone
A chemical (produced in a gland in mammals) that moves around an organism to change the function of target cell, tissues or organs
What’s a clone
An organism produced asexually that has identical genes to its parent
What’s genetic Variation
Inherited differences in organisms
What’s environmental variation
Differences in organisms as a result of the environment in which they live in
What’s an ethical issue
An idea some people disagree with for religious and or moral reasons
What’s in vitro fertilisation (ivf)
A medical procedure in which ova are fertilised outside of a women and placed in uterus to develop a baby
What are the two types of stem cells in mammals
Embryonic
Stem cells (generic I know right)
Tell me about embryonic stem cells
Present when you were a zygote and embryo (between 1 to 9 weeks old)
They divide rapidly and can differentiate into any specials cell in body so are toti potent
What is
Totipotent
Used to describe Embryonic stem cells as can turn into ANY specialised cells
Tell me about generic stem cells in mammals
They grow only in specific parts of body eg bone marrow
Used to repair body when injured
Multipotent
What’s multipotent
Used to describe usual stem cells in mammals
Means they can only turn into cell located where that cell is eg if it’s in tissue area it will turn into tissue cell
How are plant stem cells different to animal
Plant stem cells keep their ability to turn into any type of cell in Its whole lifetimes
Where are stem cells found in plants
Meristem
We can therefore take
Cutting so cells
With differentiate into identical cope of original plant(clone)
Tell me about stem cell research ethical issues
It’s an ethical issue
Believed God has a plan for all of us and we should not change it
Tell me how stem cells could be used to treat a paralysed person
By making new nerve cells to transplant into a severe spinal cord or damaged brain
How can we use stem cells to treat conditions like diabetes
Replace cells in body that are no longer working properly
What else can stem cells be used for
To replace injured or defective organs
Replace cells of the choroid in the eye to help patients see again
