B2.7 Mitosis and Meiosis Flashcards
What are the stages of mitosis? [5]
1) Prophase
2) Metaphase
3) Anaphase
4) Telephase
5) Interphase
Explain what happens during each phase of mitosis
1) Chromosomes are replicated (sister chromatids)
2) Centromere are produced either side
3) They meet in the centre and attach using spindle fibres
4) They split apart
5) Two new cells are formed
Where does mitosis occur? And where does meiosis occur?
Mitosis = all over the body Meiosis = sex organs
How many divisions are there in mitosis? And how many divisions are there meiosis?
Mitosis = once Meiosis = twice
What does mitosis create? And what does meiosis create?
Mitosis = body cells Meiosis = gametes
What is the number of chromosomes in mitosis? And what is the number of chromosomes in meiosis?
Mitosis = 46 (diploid) Meiosis = 23 (haploid)
How many cells does mitosis produce? And how many cells does meiosis produce?
Mitosis = 2 cells Meiosis = 4 cells
What is the function of mitosis? And what is the function of meiosis?
Mitosis = growth and repair, cellular reproduction Meiosis = sexual reproduction
Define what a stem cell is
A not yet specialised cell, it replicates many times and has the potential to become different cells
Define haploid
Half the DNA, gametes have haploid chromosomes
Define diploid
All the DNA, zygotes have al the DNA
Give information about the disease Polydactyly [3]
- Extra fingers and toes
- Dominant allele of the gene
- One parent carries it
Give information about Cystic fibrosis [6]
- Faulty gene in glands that secrete
- Thick secretions of mucus
- Both parents carry it
- Causes liver failure, diabetes and infections
- Traps pathogens
- Causes infertility and malabsorption
Where are stem cells found? [4]
- Bone marrow
- The brain
- In the blood
- Embryos
What are the two types of stem cells?
1) Adult stem cells
2) Embryotic stem cells
What can stem cells be used for and why?
Treating sickness as they can be easily turned into specialised cells which can slow down the process of the illness
What specifically can stem cells be used for?
treating and replacing organs and tissues
Give ethnic reasons to why people might agree or disagree with embryotic stem cells
Scientists = using embryos is better as there are more stem cells to work with
Religious people = People are just having a baby for stem cells and the embryo has the right to live
Define heterozygous
Where two alleles are different
Define homozygous
Same gene from both parents in the zygote
Define allele
Represents different variations of the gene
Different forms of the same gene
define dominant
A trait that overrides recessive genes (shown with a capital letter)
Define recessive
A trait that is hidden by the dominant. Two is needed to show characteristics
Define genotype
genes you have inherited
