Biology Ch. 10

False

An animal zygote is a haploid cell -true -false

has twice the amount of DNA present in a telophase nucleus

A cell in the G2 phase: -has twice the amount of DNA present in a telophase nucleus -has visibly distinct chromosomes -lacks a visible nuclear membrane -is in mitosis -is in cytokinesis

False

A nucleosome consists of DNA wrapped around scaffolding proteins -true -false

False

Bacteria divide asexually by mitosis -true -false

actin plus myosin

Cytokinesis in animal cells involves contraction of a ring of ____ microfilaments. -tublin plus actin -actin plus myosin -cyclin plus myosin -cohesion plus actin -cyclin plus actin

Anaphase II

During which stage of meiosis do the sister chromatids separate? -Metaphase I -Anaphase I -Metaphase II -Anaphase II -Telophase II

homologous chromosomes undergo synapsis: Sister chromatids separate and chromosomes move to opposite poles: Tetrads line up at the cell equator: Nuclear envelope forms around single-stranded chromosomes: Homologous chromosomes separate and move to opposite poles: Crossing-over occurs: Telophase II Anaphase I Prophase I Metaphase I Anaphase II Prophase I

Prophase I Anaphase II Metaphase I Telophase II Anaphase I Prophase I

Prevent DNA strand from tangling

The function if nucleosomes is to: -prevent DNA strands from tangling -help DNA replicate -make RNA synthesis possible -prevent RNA from tangling with DNA during transcription -prevent histones from tangling

True

The nuclear envelope fragments during the prometaphase stage -true -false

Cyclins fluctuate during the cell cycle

To control the cell cycle, -the activity of Cdks stays the same throughout the cell cycle -cyclins fluctuate during the cell cycle -Cdks are active only when they are released from cyclins -the anaphase-promoting complex stimulates DNA replication -M-Cdk inhibits mitosis

Increased genetic diversity

What evolutionary advantage is provided by sexual reproduction? -increased genetic diversity -generation of clones -production of genetically identical offspring -possibility of polyploidy in the progeny -removal of all genetic mutations

Condensation of the chromatin into chromosomes

Which event occurs in prophase II? -disappearance of the spindle -condensation of the chromatin into chromosomes -formation of the chiasmata -crossing over occurs -formation of the cleavage furrow

Animal gametes

Which of the following is produced by meiosis? -somatic cells -animal gametes -polypoid cells -diploid cells -zygotes

Cell plate

cytokinesis in plant cells occurs via the formation of an -aster -mitotic spindle -golgi complex -cell wall -cell plate

Circular DNA molecule many times larger than the cell

A bacterial chromosome consists of: -linear DNA molecule many times larger than the cell -circular DNA molecule many times larger than the cell -circular DNA molecule smaller than the cell -linear DNA molecule smaller than the cell -linear or circular DNA molecule smaller than the cell

One egg cell and three polar bodies

At the completion of oogenesis, _______ are produced -male gametes -four sperm cells -four egg cells -one egg cell and three polar bodies -haploid spores

False

For each animal cell that begins oogenesis, the number of ova produced is four -true -false

Their similar and characteristic staining patterns

Homologous chromosomes can be identified and/or characterized by: -Their similar and characteristic staining patterns -the different centromere positions in the maternal versus paternal chromosomes -those chromosomes that do not have partners -paternal chromosomes only -maternal chromosomes only

True

Homologous pairs of chromosomes separate during meiosis I -true -false

False

In cell cycle, DNA is replicated during the G2 phase -true -false

Mitosis, diploid, meiosis

In fungi and protists, gametes produced by _____ of haploid cells fuse to form a ______ zygote, which then undergoes _____ to restore the haploid chromosome number -mitosis, diploid, meiosis -meiosis, diploid, mitosis -mitosis, haploid, meiosis -meiosis, haploid, mitosis -mitosis, diploid, mitosis

False

Microtubules of the mitotic spindle attach directly to each chromosome at the centromere -true -false

Prometaphase Telophase Prophase Telophase Anaphase Prometaphase Prophase Metaphase

Spindle microtubules attach to kinetochores: Cytokinesis generally begins: Chromatin condenses: Chromosomes decondense: Sister chromatids separate at their centromeres: Nuclear envelope fragments: Mitotic spindle forms: Chromosomes align at the cells midplane: Anaphase Prometaphase Metaphase Prophase Telophase

Mitotic spindle; anaphase

The ____ is responsible for the separation of the chromosomes during the ____ of mitosis. -cell wall; anaphase -mitotic spindle; interphase -mitotic spindle; anaphase -kinetochore; prophase -centromere; telophase

Sister chromatids; cohesion proteins

________ contain identical DNA sequences and are held together by _______ during mitosis -daughter chromosomes; hydrogen bonding -daughter chromosomes; ionic bonding -sister chromatids; spindle fibers -sister chromosomes; histone proteins -sister chromatids;cohesion proteins

Genes

________ organized on chromosomes carry the information that controls the functions of the cell -proteins -nucleosomes -asters -genes -histones

True

Enzymes required for DNA replication are synthesized during -true -false

Chromatin

Eukaryotic chromosomes are composed of -proteins only -chromatin -DNA only -circular chromatin -karyotypes

A and C

Figure 10-1: In accompanying figure, which combination of letters accurately represents two sister chromatids? -A and B -A and C -A and D -A and E -B and F