BIOL 101
ESTUDY UIDE UIZ G : Q 6
Quiz Preparation Tasks: Your Answers and Notes
11 Elegant Responsiveness
What is a typical site of origin of leptin hormone? Hypothalamic brian region
A hormone that controls a person’s appetite might bind to hormone ________
proteins on membranes in the brain.
receptor
In a normal person, what is the effect of elevated leptin levels in the
bloodstream?
However, mutant cell surface receptors for leptin molecules
may result in weak leptin binding, weakened subsequent
hormonal signalling and weakened appetite suppression.
11.1 Life’s Responsiveness
If a bog plant designed to catch insects proves unable to do so, the result will
be starvation for the element ____________.
nitrogen
Why does a living thing need to be responsive? Its environment is
__________.
changing
Based on Figure 11.5 in your text, what is the role of homeostatic
mechanisms? Maintaining internal ____________ ___________.
Chemical stability
When an environmental change shifts an organism’s internal chemistry
toward a new state, the organism’s response is to return its chemistry toward
the original state. This tendency on the organism’s part is
called______________.
Homeostasis
11.2 Responsiveness at the Transcriptional Level
The three genes whose protein products control lactose use lie within the
lactose operon. They are called ________________ genes.
structural
When RNA polymerase transcribes these genes, the proteins needed to
____________ in and ____________ lactose will be present and active. (In
Figure 11.7b, these protein products are called “Lactose permease” and “β-
galactosidase”. “Transacetylase” is needed for another function in lactose
usage.)
Transport in and degrade lactose
How does RNA polymerase “know” where to begin transcribing these genes?
It recognizes a ____________ site where it preferentially binds. See Figure
11.7b.
promoter
A repressor protein (that can block RNA polymerase’s way and keep it from
transcribing the lactose genes) binds to a short sequence of DNA bases called
the ______________ region. See Figure 11.7a.
operator
When there is little or no lactose present in a bacterium’s environment then
the ________ sequence in the DNA is bound by a repressor protein. See
Figure 11.7a
RNA?
When there is little or no lactose present in a bacterium’s environment then
the gene for the lactose transport enzyme is repressed, it is not trans-
__________ and translated. See Figure 11.7a, right-hand portion.
scribed
When there is little or no _________ present in a bacterium’s environment
then the gene for the lactose degradation enzyme is not transcribed and
translated. See Figure 11.7a.
lactose
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BIOL 101
When there is little or no lactose present in a bacterium’s environment then
the ________ operon is shut down. See Figure 11.7a.
lactose
In the lactose operon of E.coli, what causes the repressor protein to change
the shape of its DNA-binding site? The repressor protein binds to the inducer
______-____________. See Figure 11.7b, left-hand portion.
Allo lactose
What is the resultant effect of the repressor protein’s shape change on lactose
gene expression? It has a reduced ability to bind ___________DNA. RNA
polymerase is now free to: ______________________ (See Figure 11.7b,
right-hand side.
Operator
When the lactose operon is functioning the bacterium can successfully
_______ in and breakdown lactose because ________ and degradation genes
are being transcribed. (See the question “When RNA polymerase transcribes”
above).
RNA polymerase is then free to transcribe the DNA and the
products of the lactose operon become available to break
down the lactose that is presen
11.3 Responsiveness at the Cellular Level
After a fly trips the sensory hair on the modified leaf of a Venus fly trap, what
is the very next step in the closing process? The hair touches start a _______.
Small electrical potential
According to Figure 11.10, list the complete sequence of chemical events in
the closure of a Venus Fly trap.
Stimulus
Electrical potential
Proton pumping
Acid ph
Enzymes active
Wall loosens
Waters rushes in
Cell expand
Trap closes
In the Venus Fly trap, the enzyme expansin helps to close the trap by
loosening the _________ _______ in the plant’s cell walls.
Cellulose fibers
Once __________ has weakened the cellulose in the walls of the leaf trap
cells, _______ rushes into the cells expanding them and closing the trap.
Expansin enzymes, water
11.5 Responsiveness at the Organ System Level
The suprachiasmatic nuclei in the brain help the human nervous system to
respond to daily alterations in ______ and ______.
Light and darkness
The ______________ _________ enable the nervous system to respond to
light/dark alterations through their stimulation of the pineal _____ in the
center of your head.
Suprachiasmatic nuclei; gland
The human nervous system responds to daily alterations in light and darkness
by influencing melatonin levels in the ___________.
bloodstream
The human nervous system responds to daily alterations in light and darkness
by controlling how much melatonin reaches the ____________ nuclei.
suprachiasmatic
The human nervous system responds to daily alterations in light and darkness
by modulating the amount of __________ signal secreted by the
hypothalamus.
melatonin
The human nervous system responds to daily alterations in light and darkness
by influencing _____________ levels secreted by the thyroid gland.
thyroxin
The human nervous system responds to daily alterations in light and darkness
by changing the basal ___________ rate of your cells.
metabolism
One effect of melatonin on the suprachiasmatic nuclei is that it corrects the
_________ of their day/night signaling system.
periodicity
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BIOL 101
What is the general effect of decreasing melatonin levels in the body? Higher responsiveness, wake up faster.
List five different reasons some individuals take a melatonin supplement. Slow:
multiple sclerosis, heart disease, epilepsy, osteoporosis
Cure: insomnia, jet lag, six types of cancer, depression,
anxiety, high cholesterol levels
12 Informational Continuity in Organisms
Biological information is preserved within the base sequence of what
molecule?
DNA
12.
1
Reproduction: Asexual and Sexual
Asexual Reproduction
Give three examples of asexual reproduction methods in plants. Runners, tubers, clone
What method of asexual reproduction does the plant utilize?Kalanchoe New plants start as marginal projections of the Kalanchoe
plant’s leaves! They simply break off of an existing plant,
primary roots already intact, fall to the ground, and take root
to become new individuals—again—genetically identical to
the parent plant.
What method of asexual reproduction does the Iris plant utilize? Iris flowers spread by means of underground “rhizomes”
which are modified stems. Buds generate new aerial shoots
which later flower.
Sexual Reproduction
List four disadvantages of sexual reproduction. Only 50% of genes pass
No selectively optimal combo of genes can pass
Sex displays are cumbersome and vulnerable
Energy to find a mate
One major advantage of sexual reproduction over asexual reproduction is that
in sexual reproduction the population has increased _________ variability.
genetic
An “allele” is a specific alternate form of a _______. gene
Two slightly different versions of genes that lie at the exact same location on
two separate homologous chromosomes are called ____________.
alleles
The phrase, “two homologous sets of genes” can mean either two similar
collections of genes coming from your two separate _____________, or two
similar collections of genes arranged on two complete sets of
_____________.
Parents, copies? Of chromosomes (of all of the information
needed for effective functioning as a human)
12.
2
Preparing Reproductive Cells for Multicellular
Organisms
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BIOL 101
The Challenge of Making a Reproductive Cell
A reproductive cell be made to differ genetically from other normal must
body cells. It must differ in what critical way? If it is no different genetically
from normal body cells, what will happen when it fuses with another such
cell?
They continue to double; requires mitosis
How Can This Ploidy Problem be Solved?
The specialized process that halves the number of chromosomes during sex
cell formation is named ____________.
meiosis
Meiosis: A Triumph of Genome Reduction and Genetic
Variability
List in order, eight successive stages in the process of meiosis. Prophase
Metaphase
Anaphase
Telophase
Prophase II
Metaphase II
Anaphase II
Telophase II
The stage of meiosis in which the total number of chromosomes is reduced to
half is called the reduction division. Which stage (listed above) brings this
about?
Anaphase I or II?
For each of 23 pairs of chromosomes, the haploid egg cell will have either a
maternal or paternal chromosome, but it can be different for each pair. This
explains how the process of meiosis contributes to genetic _____________.
recombination
Differentiation of Reproductive Cells: A Biological Context
In the human life cycle, diploid cells undergo a cell division process called
__________. The resulting haploid cells later fuse during ___________
which regenerates diploid cells. See Figure 12.13.
Meiosis, fertilization
Early in your own development there exists a small subset of diploid cells
called primary germ cells. Where do they begin to develop? Within: Where do
they migrate to and lodge? What process will they later go through to become
haploid? What will they be called right before the first cell division in that
process? (See Figure 12.15)
. diploid
maturation process begins prenatal life, called primary oocyte
(or secondary oocyte)
oogoniom/spermatogoniom
Haploid secondary spermatocytes go on directly to complete meiosis forming
four spermatid cells. These will eventually differentiate into sperm cells. The
last stage of meiosis (that generates the spermatids) is called ____________.
(Review the stages in Fig 12.12)
Telophase
12.
3
Reproduction in Humans
Oogenesis in Humans
A secondary oocyte that has undergone one meiotic division, a polar body, a
fluid-filled cavity, and a spherical cluster of nutritive cells are all found within
a structure called a mature __________.
ovary
For about half of a woman’s monthly cycle, the hormone ________ leaves the
pituitary gland and, at the ovary, signals it to bring a more advanced
_________ to complete maturity.
Follicle-stimulating hormone (FSH), follicles
What hormone, suddenly secreted from the anterior pituitary gland in high
levels causes the mature follicle to rupture from the ovary surface?
estrogen
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BIOL 101
The reproductive system uses the hormones ________ and (later on)
____________ to “think ahead.” They guide the preparation of the uterus for
its role in supporting pregnancy.
Estrogen, progesterone
The mature egg, once ruptured from its follicle is swept into the
_____________ by finger-like fringes called __________.
Fallopian tubes, fimbriae
Normally a fertilized egg ends its journey temporarily by implanting within
the wall of what structure?
uterus
Spermatogenesis and Fertilization
Sperm cell production occurs within the interior lining of the
______________ tubules.
seminiferous
Using Figure 12.21, list in order the sequence of cell types that produce a
sperm cell.
Primary spermatocyte
Secondary spermatocyte
Early spermatids
Late spermatid
haploid
Leydig cells, testosterone, LH hormone and FSH hormone are all involved in
the control of _________ cell production.
sperm
List in order the structures by which a mature sperm cell travels from the
epididymis to the female’s reproductive tract. See Figure 12.22.
Epididymis
Vas deferens
Seminal vesicle
Ejaculatory duct
Urethra
(penis)
Penetration of the egg’ zona pellucida by the sperm cell is a process driven by
the activity of hydrolytic ___________.
enzymes
The quintessential (most basic/most important) moment of fertilization of the
egg by the sperm cell occurs when the male and female ________ fuse
together into one nucleus. See Figure 12.23b, c.
pronucleus
12.
4
Reproduction Constrained, Part 1: Control of Birth
Which methods of birth control work by blocking sperm on its journey from
the testicle to the Fallopian tube?
condom
Which methods of birth control work by altering the hormonal chemistry of
the female partner?
Oral contraceptives
Name a birth control method that is primarily contraceptive and secondarily
abortive in its effects.
The pill
Which of the following methods by which human conception can be
postponed is least invasive of the complexity of human physiology? The
rhythm method, the vaginal ring, oral contraceptives, tubal ligation,
vasectomy.
rhythm
12.
5
Reproduction Constrained, Part 2: Destruction of
Life
Philosophers and Theologians Attempt to Define Personhood
How did the philosopher Plato set about to determine when human life
begins? What term did he use? Life begins at _________________. When did
he consider ensoulment to occur?
Ensoulment at birth
Aristotle, the “Father of Biology,” believed that a human being became a
person once they exhibited what characteristic?
Became animated, 40 to 80 days
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BIOL 101
Biologists Work to Define the Human Individual
One excellent biological approach to determining when a mother and her
conceptus become separate individuals is the detection of the first measurable
_______ _____ via electroencephalography.
Brain waves
At about what time or stage of development does male genetic information
from the sperm begins to be translated into protein products? (This is used by
some to determine when a mother and her conceptus become separate
individuals.) See Figure 12.31
implantation
Destruction of Human Life Takes Various Forms
What chemical combination is commonly used to terminate a pregnancy,
killing the little one? _____________ and _______________.
Mifepristone & prostaglandin
Briefly describe a common surgical procedure for aborting a little one. surgical procedures exist that dilate the cervix and either suck
or scrape the developing human embryo from the surface of
the uterine wall
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