Study Guide Quiz 6 BIOL 101 PDF

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Study Guide Quiz 6 BIOL 101...

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BIOL 101

ESTUDY

GUIDE: QUIZ 6

Quiz Preparation Tasks:

11

Your Answers and Notes

Elegant Responsiveness What is a typical site of origin of leptin hormone? A hormone that controls a person’s appetite might bind to hormone ________ proteins on membranes in the brain. In a normal person, what is the effect of elevated leptin levels in the bloodstream?

Hypothalamic brian region receptor 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 __________. Based on Figure 11.5 in your text, what is the role of homeostatic mechanisms? Maintaining internal ____________ ___________.

changing

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

Chemical stability

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. 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 “βgalactosidase”. “Transacetylase” is needed for another function in lactose usage.) How does RNA polymerase “know” where to begin transcribing these genes? It recognizes a ____________ site where it preferentially binds. See Figure 11.7b. 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.

structural

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 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. 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.

RNA?

Transport in and degrade lactose

promoter operator

scribed 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. 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.

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. 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).

Operator

Allo lactose

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 Cellulose fibers

In the Venus Fly trap, the enzyme expansin helps to close the trap by loosening the _________ _______ in the plant’s cell walls. 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 ______. The ______________ _________ enable the nervous system to respond to light/dark alterations through their stimulation of the pineal _____ in the center of your head. The human nervous system responds to daily alterations in light and darkness by influencing melatonin levels in the ___________.

Light and darkness

The human nervous system responds to daily alterations in light and darkness by controlling how much melatonin reaches the ____________ nuclei. The human nervous system responds to daily alterations in light and darkness by modulating the amount of __________ signal secreted by the hypothalamus. The human nervous system responds to daily alterations in light and darkness by influencing _____________ levels secreted by the thyroid gland. The human nervous system responds to daily alterations in light and darkness by changing the basal ___________ rate of your cells. One effect of melatonin on the suprachiasmatic nuclei is that it corrects the _________ of their day/night signaling system.

suprachiasmatic

Suprachiasmatic nuclei; gland bloodstream

melatonin thyroxin metabolism periodicity

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BIOL 101

What is the general effect of decreasing melatonin levels in the body? List five different reasons some individuals take a melatonin supplement.

Higher responsiveness, wake up faster. 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?

12. 1

DNA

Reproduction: Asexual and Sexual Asexual Reproduction Give three examples of asexual reproduction methods in plants. What method of asexual reproduction does the Kalanchoe plant utilize?

What method of asexual reproduction does the Iris plant utilize?

Runners, tubers, clone New Kalanchoe plants start as marginal projections of the 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. 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.

One major advantage of sexual reproduction over asexual reproduction is that in sexual reproduction the population has increased _________ variability. An “allele” is a specific alternate form of a _______. Two slightly different versions of genes that lie at the exact same location on two separate homologous chromosomes are called ____________. 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 _____________.

12. 2

Only 50% of genes pass No selectively optimal combo of genes can pass Sex displays are cumbersome and vulnerable Energy to find a mate genetic gene alleles Parents, copies? Of chromosomes (of all of the information needed for effective functioning as a human)

Preparing Reproductive Cells for Multicellular Organisms

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BIOL 101

The Challenge of Making a Reproductive Cell A reproductive cell must be made to differ genetically from other normal 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? 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 _____________.

Anaphase I or II? 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. 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) 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)

12. 3

Meiosis, fertilization . diploid maturation process begins prenatal life, called primary oocyte (or secondary oocyte) oogoniom/spermatogoniom Telophase

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 __________. 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.

ovary

What hormone, suddenly secreted from the anterior pituitary gland in high levels causes the mature follicle to rupture from the ovary surface?

estrogen

Follicle-stimulating hormone (FSH), follicles

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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. The mature egg, once ruptured from its follicle is swept into the _____________ by finger-like fringes called __________.

Estrogen, progesterone

Normally a fertilized egg ends its journey temporarily by implanting within the wall of what structure?

uterus

Fallopian tubes, fimbriae

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 sperm

Leydig cells, testosterone, LH hormone and FSH hormone are all involved in the control of _________ cell production. 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.

Penetration of the egg’ zona pellucida by the sperm cell is a process driven by the activity of hydrolytic ___________. 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.

12. 4

pronucleus

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? Which methods of birth control work by altering the hormonal chemistry of the female partner? Name a birth control method that is primarily contraceptive and secondarily abortive in its effects. 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.

12. 5

Epididymis Vas deferens Seminal vesicle Ejaculatory duct Urethra (penis) enzymes

condom Oral contraceptives The pill rhythm

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? Aristotle, the “Father of Biology,” believed that a human being became a person once they exhibited what characteristic?

Ensoulment at birth 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 _______________. Briefly describe a common surgical procedure for aborting a little one.

Mifepristone & prostaglandin 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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