chapter 8- making ATP Flashcards
chromosomes duplicate and one copy moves to opposite side of cell
first step of binary fission (prokaryotic cell division)
cell elongates
step 2 of binary fission
plasma membrane pinches in and more cell wall is made
last step of binary fission
what are chromosomes made of
protein and dna
exact copy of original chromatid attached at the centeomere
sister chromatid
growth, organelles double
G1 of interphase
chromosome replication (synthesis of dna)
S phase of interphase
more growth, and proteins are made
G2 of interphase
thick, condensed chromosomes, nucleus disappears
prophase of mitosis
chromosomes line up in the middle of the cell along invisible metaphase plate
metaphase of mitosis
sister chromatids move to opposite poles
anaphase of mitosis
nucleus reforms at round thick chromosomes and either a cleavage furrow or cell plate appears
telophase of mitosis
what is the purpose of cell division/ reproduction in eukaryotic organisms
to heal/repair
growth and development
asexual reproduction (mitosis)
sexual reproduction (meiosis)
cleavage furrow
occurs in animal cell telophase where membrane pinches in and makes figure 8 shape
cell plate
occurs in a plant cell in telophase and creates cell wall
what is the purpose of meiosis vs mitosis
meiosis is for sexual reproduction (makes gametes) and to reduce chromosome number by half
mitosis is for asexual reproduction
pairs of chromosomes that are similar in size shape and carry the same types of genes, one from each parent
homologous chromosomes
meiosis vs mitosis
meiosis makes gametes (sexual reproduction) and mitosis is for asexual reproduction
meiosis creates 4 haploid cells while mitosis creates 2 identical diploid daughter cells
meiosis goes through 2 stages of division while mitosis only has one
diploid cells (2n)
has 2 sets of chromosomes (46)
haploid cells (n)
has 1 set of chromosomes (23)
condensed chromosomes
homologous pairs synapse and cross over
prophase 1 of meiosis
homologous pairs line up in middle of cell
metaphase 1 of meiosis
homologous pairs separate and move to poles
anaphase 1 of meiosis
nucleus reforms around chromosomes
cleave furrow or cell plate forms
telophase 1 of meiosis
cytokinesis of meiosis 1
2 haploid daughter cells
prophase 2 of meiosis
condensed chromosomes
metaphase 2 of meiosis
chromosomes line up in the middle
anaphase 2 of meiosis
sister chromatids separate
telophase 2 of meiosis
nucleus reforms
cytokinesis of meiosis 2
4 haploid gametes
what events increase genetic variability in meiosis
prophase 1
metaphase 1
fertilization
how does prophase 1 increase genetic variability
homologous pairs synapse and cross over between non sister chromatids
how does metaphase 1 increase genetic variability in meiosis
random alignment of homologous pairs
advantages of asexual reproduction
fast, efficient, and able to invade habitat quickly
disadvantage of asexual reproduction
low genetic diversity
advantage to sexual reproduction
increase genetic variability
disadvantage of sexual reproduction
mutations
faliure of chromosomes to separate during anaphase 1 or 2
nondisjunction (mistakes in meiosis)
example of nondisjunction
trisomy —-> down syndrome
mutation where a segment is removed from a chromosome (creates shorter chromosome)
deletion
mutation where segment is repeated (chromosome is longer)
duplication
mutation where a segment is reversed (reverses nucleotide sequence)
inversion
mutation where a segment breaks off one chromosome and attaches to another (changes structure if 2 chromosomes)
translocation
