Red
What are gametes?
Reproductive cells (egg and sperm)
Each chromosomes after DNA replication has two identical parts called ___.
Chromatids
T/F All somatic cells divide at the same rate
False
What are the products of meiosis 1?
Are gametes haploid or diploid cells?
In what type of organism is the genome a single circular chromosome?
Prokaryote
Cells in the __ phase have ceased dividing.
G0
What does the first interphase checkpoint check for?
-Adequate cell size and resources to continue
-Genomic DNA damage
What are the products of meiosis 2?
Four haploid daughter cells with un-replicated chromosomes
Are zygotes haploid or diploid?
Diploid, because it contains two haploid sets of chromosomes.
What is the ploidy of a somatic cell?
Diploid (2n)
Which checkpoint checks to see if all the chromosomes are attached at the mitotic spindle?
M checkpoint
How many cell divisions occur in meiosis? What are they called?
-Meiosis 1 (reductional division)
-Meiosis 2 (equational division)
When does crossing over occur?
Prophase of meiosis 1
In metaphase 2, are the two sister chromatids of each chromosome genetically identical?
No, because crossing over occurred in meiosis 1.
What specialized protein structure forms at the centromere of each chromatid (two per chromosome) during prometaphase?
When are new cyclin molecules synthesized?
S and G2
What are some mechanisms that contribute to genetic variation in offspring? Give at least 2 examples.
Independent assortment of chromosomes
Crossing over
Random fertilization
Sexual life cycles → mutations that create different versions of genes (alleles)/reshuffling
When does DNA replication occur in meiosis?
Occurs during interphase before meiosis 1 but NOT meiosis 2
Where do the microtubules of the spindle originate during mitosis in both plant and animal cells?
Centrosome
How does the alignment of homologous pairs at the metaphase plate differ between mitosis and meiosis?
During prophase 1 (meiosis), duplicated homologs pair up and crossing over occurs. Synapsis and crossing over do not occur during the prophase of mitosis.
It prevents the cell from entering into mitosis until cell size, resources, and proper DNA replication has been confirmed.
G2 checkpoint
How does the separation of homologs differ between mitosis and meiosis?
In the anaphase of mitosis, sister chromatids separate.
In the anaphase 1 of meiosis, duplicated chromosomes of each homologous pair move toward opposite poles but the sister chromatids of each duplicated chromosome remain attached.
A mutation results in a cell that no longer produces a normal protein kinase for the M phase checkpoint. Which of the following would likely be the immediate result of this mutation?
The cell would undergo normal mitosis, but fail to enter the next G1 phase.
Which of the following triggers the cell's passage past the G2 checkpoint into mitosis?
MPF