Ch. 1 and 2 Flashcards
Functional chromosomes have:
a centromere, telomeres, origins of replication
What are the 4 chromosome structures
metacentric, submetacentric, acrocentric, telocentric
Alleles
Different variations of a gene
Mitosis
Make two genetically identical daughter cells
Meiosis
Make nonidentical haploid gametes
explain the steps to mitosis
interphase, prophase, metaphase, anaphase, telophase, and cytokinesis
cell cycle
G1 (or G0), S, G2, M, and cytokinesis
Where are the checkpoints in the cell cycle?
G1/S, G2/M, Spindle-assembly (M)
microtubules
made of tubulin subunits; tubulin subunits added to and removed from both ends of the microtubules; originate at centrosomes; connect to the kinetochore
gametogenesis
cell division producing sex cells
What type of division is Meiosis I
reduction division
What type of division is Meiosis II
equational division
What happens in Prophase I
chromosomes condense, dyads are visible, crossing over between homologous pairs
What happens in metaphase I
homologous pairs line up along the metaphase plate
Anaphase I
Homologous pairs separate and move toward opposite poles (sister chromatids remain attached at the centromere)
Telophase I
Chromosomes arrive at opposite poles; nuclear membrane reforms; cytokinesis
Meiosis II
The second meiotic division is analogous to a mitotic division in that sister chromatids separate
Maternal + paternal=
homologous pair
Eukaryotic DNA is…
linear and organized into chromosomes
the arm at the top of the chromosome is the ___ arm and the arm at the bottom is the..
p, q-arm
chromosomes are ______ in metaphase I
randomly distributed (random assortment)
When does crossing over occur
prophase I
when does random assortment occur
metaphase I
cohesin
a protein that hold chromatids together
during anaphase I, what is the interaction between cohesin and shugoshin
cohesin at the centromere is protected by shrugoshin (preventing separation of the 2 sister chromatids during anaphase I)
What are chromosomes
condensed chromatin
