Lab 8 Meiosis And Genetics Flashcards
Why are DNA bindings fluorescent dyes used?
To help see the DNA when loading
What is EtBr dye?
A type of loading dye that binds to the DNA that helps us see it in the gel
How is he end result of mitosis different from meiosis?
Mitosis has two identical daughter cells (diploid). Exact copy of original parent cell just now divided
Meiosis produces 4 haploid daughter cells.
What is the charge of DNA?
- due to the phosphate backbone
What is the gel made from and what does it look like at a molecular level?
Across gel made of polysaccharides
Looks like a sponge coral
What is a DNA ladder?
Ladder system that is used to determine the size of DNA that has been run through a gel
Why do we visualize DNA under UV light?
Because DNA fluoresces when exposed to UV light if DNA has been bound to EtBr.
Why is meiosis necessary for sexual reproduction?
It’s needed to produce the haploid gametes
What is the goal of meiosis?
To increase the variability of the genetics spread over four haploid cells
What happens in meiosis one that increase the variability of the resulting gametes?
Cross over allows chromosomes of maternal and paternal origin to exchange DNA segments
How many chromatids and chromosomes are in each phase of meiosis 1?
Metaphase 1: 8, 4
Anaphase1 : 8,4
Telophase 1: 4,2 per cell
How many chromatids and chromosomes are in each phase of meiosis 2?
Prophase2: 4,2
Metaphase 2: 4,2
Anaphase 2: 4,2
Telophase 2: 2,2
How many homologous pairs of chromosomes were present in each daughter cell at the end of meiosis 1?
0
At the end of meiosis 2 did all the daughter cells have identical chromosomes, why?
No
Because crossover has allowed genetic material to be passed to each chromatid
How is the chromosome content of daughter cells different from that of the parent cell?, did the basic chromosome number change? Did ploidy level change?
They have exchanged genetic information in the cross over
Yes chromosome number has changed from 4 to 2 per cell
Ploidy level has changed from diploid to haploid
