Unit 6: Meiosis Flashcards
What does DNA mean?
double stranded molecule composed of repeating nucleotides that contain genetic material.
What is Chromatin?
relaxed, unwound DNA. Found kinda like noodles.
What is Chromosome?
tightly wound and condensed DNA that is ONLY found right before a cell divides. This condensed structure allows for organized, precise cell division.
What is a sister chromatid?
Each half of a replicated chromosome.
What two type of cells do we have in our body?
Somatic Cells and Gametes
What are somatic cells?
they are body cells and are diploid.
What are gametes?
They are sex cells and are haploid.
What are diploid (2n) ?
Two full sets of DNA, one from mom and one from dad
What does the “n” mean?
the sets of chromosomes
How many chromosomes are in a human somatic cell?
46
So, 2n=46
What are haploid?
Only one full set of DNA. Is a combo of genes from gamete maker. (So mixed up genes from one parents 2 full sets, STILL ONLY ONE SET)
What are egg cell chromosomes made out of?
mixture of the mom’s genes from her 2 full sets
What are sperm cell chromosomes made out of?
mixture of the dad’s genes from his 2 full sets
How much chromosomes does each egg or sperm cell have?
23
n=23
What are the type of chromosomes in our cells?
Autosomes and Sex chromosomes
What are autosomes?
chromosomes that carry traits that make you who you are. (the first 22 pairs of chromosomes)
What are sex chromosomes?
Carry traits that make you who you are AND determine your biological sex. (ONLY found in 23rd pair known as X or Y)
What karyotype determines if you are female? What about male?
XX = female
XY = male
What is a karyotype?
Each pair of chromosome sets.
What is meiosis?
the process of cell division that makes gametes.
Where does meiosis take place?
In the gonads like ovaries in females and testes in males.
What is the goal of meiosis?
To produce haploid sex cells with HALF the number of chromosomes as diploid body cells.
Why is meiosis so important?
Sexual reproduction wouldn’t occur because it needs to produce 2n. Without it, it would reproduce DOUBLE the DNA, so no baby, sorry.
What is mitosis?
cell division that takes place to create 2 idenitical diploid daughter cells, helps with blood cells etc.
What is a centriole/centrosome?
Two centrioles make up the centrosome.Centrosomes are the structure in the cell that spindle microtubules grow from.
What is a centromere?
region where two sister chromatids are joined after a
chromosome replicates
What is a spindle appartus?
microtubules that grow from the
centrosome, attach to chromosome centromeres, and move chromosomes around
What are microtubles?
microfilaments that elongate during cell division only to attach to chromosomes and move them around
