Homologous pairs of chromosomes are
identical to each other
divided in anaphase 2
duplicated in prophase 2
similar to each other
The kinetochore contains
DNA and RNA
microtubule phosphatases
motor proteins
phosphatases
protein kinases
Apoptosis can occur when a cell
is damaged
is no longer needed
is too small
damaged and not needed
all three
Which of the following is not a second messenger?
cAMP
inositol triphosphate IP3
calcium ions
diacylgylcerol DAG
protein kinase
A nucleosome is formed by
the fusion of DNA and proteins
the winding of DNA around histone proteins
ribosomes and mRNA
the fusion of two nucleid
the winding of DNA around chromatin
Unpacking of chromosomes and the formation of a new nuclear envelope is a characteristic of what stage of mitosis?
prophase
metaphase
anaphase
telophase
cytokinesis
Separation of sister chromatids is a hallmark of which phase of mitosis?
Some plants exhibit alternating generations of haploid and diploid multicellular organisms. The haploid multicellular gametophyte arises from single-cell spores by the process of
meiosis
mitosis
spermatogenesis
parthenogenesis
oogenesis
A common feature of receptor-mediated signaling is
amplification
autophosphorylation
regulation
amplification and regulation
A cleavage furrow forms during
plant cell apoptosis
animal cell apoptosis
plant cell cytokinesis
animal cell cytokinesis
Synaptic signaling alters membrane potential through which of the following signaling mechanisms?
G-protein coupled receptors
tyrosine kinase receptors
ganglioside receptors
ligand-gated ioin channels
Failure of chromosomes to assort independently in meiosis could lead to
increased crossing over
greater or lesser chromosome numbers in gametes
smaller chromosomes
mutations
larger chromosomes
The cell plate forms during
animal metaphase
plant cytokinesis
plant metaphase
plant morphogenesis
Checkpoints in the cell cycle are controlled by
the concentration of cyclin-dependent kinases
the cytoplasmic concentration of cAMP
the concentration of cyclins
mitotic spindle length
A liver cell of an organism has 8 chromosomes. How many chromosomes will be in a gamete of that organism?
2
4
8
16
32
At which stage of meiosis are sister chromatids separated from each other?
prophase 1
prophase 2
anaphase 1
anaphase 2
Prokaryotes propagate by
karyogenesis
oncogenesis
binary fission
A grape vine stem is placed in water with rooting hormone. New growth begins to germinate. What process drives that new growth?
gametogenesis
non-disjunction
Which of the following chemical signaling systems requires transport in the circulatory system?
synaptic
paracrine
endocrine
autocrine
Mitosis results in two _____ cells, while meiosis results in _______ haploid cells.
diploid/two
haploid/four
haploid/two
diploid/four
Which of the following is a diploid cell?
zygote
skin cell
egg
zygote and skin cell
What is a likely evolutionary advantage of sexual reproduction over asexual reproduction?
produces a greater number of offspring
lower chance of using up resources
requires fewer steps
greater variation in offspring
more cost effective
A drug that prevents translocation of activated receptors from the cytoplasm to the nucleus will affect which signaling system?
synaptic transmission
paracrine signaling
steroid hormones
gap junction signaling
Which of the following is common to both meiosis or mitosis?
fertilization
phosphorylation
interphase
When phosphorylated, cyclin-dependent kinases
phosphorylate cyclins
phosphorylate target proteins
dephosphorylate proteins
dephosphorylate cyclins
Activated steroid hormone receptors are also
calcium channels
phosphodiesterases
protein phosphatases
transcription factors
Tyrosine kinase receptor enzymatic activity is enhanced by
tyrosine binding to the receptor
G-protein binding
GTP
A haploid dominant organism, such as fungi arise from spores that are
haploid
euploid
diploid
tetraploid
Fertilization results in
a zygote
a diploid cell
a cell with new genetic cominations
none
all
Independent assortment in meiosis occurs during
metaphase 1
G-proteins are characterized by
coupling to ganglioside receptors
ATPase activity
localization in the cytoplasm
a requirement of GTP binding for activation
When during meiosis are cells haploid?
after meiosis 1
after meiosis 2
after interphase
after meiosis 1 and 2
G-proteins are composed of
alpha, beta, and gamma subunits
a GTPase and protein kinase A
MAP kinases
GTP and protein
Steroid hormone receptors are found in the
cytoplasm
plasma membrane
extracellular matrix
circulatory system
Seedless watermelon plants have 33 chromosomes. Why don't their seeds properly develop?
meiosis cannot evenly reduce chromosome number
crossing over cannot occur
there is a high mutation rate in these plant cells
these cells cannot undergo proper mitosis
A phospholipase breaks down phospholipids into
calcium ions and IP3
IP3 and cAMP
DAG and cAMP
calcium ions and cAMP
IP3 and DAG
At the end of the mitotic phase of the cell cycle, each daughter cell has
the same amount of DNA as at the very beginning of the S phase
the same amount of DNA as at the very end of G2
half as much DNA as in G1
the same amount of DNA as at the very beginning of G2
twice as much DNA as in G1
How are DAG and IP3 formed?
protein kinase C enzyme activity
phosphorylation of cAMP
they are hormones that originate from signaling cells
phospholipase breakdown of plasma membrane
activation of protein kinase A
G proteins require which of the following for activation
PKA
adenylyl cyclase
PKC
IP3
Adenylyl cyclase uses _________ as a substrate to synthesize ________.
ATP; pyrophosphate
AMP; cAMP
cAMP; ATP
pyrophosphate; cAMP
ATP; cAMP
The haploid number of a human cell is
12
23
46
92
Synapses of homologous pairs of chromosomes is required for
crossing over
parthenogensis
independent assortment
DNA synthesis occurs during which phase of the cell cycle?
G1 phase
G0 phase
S phase
G2 phase
M phase
Identical copies of chromatin held together at the centromere are called
sister chromatids
histones
chromatin
nucleosomes
homologous chromosomes