Liberty university biol 101 quiz 6 complete solutions

A hormone that controls a person’s appetite might bind to ____________ proteins on membranes in the brain.

What is the typical site of origin of leptin hormone?

In a normal person, what is the effect of elevated leptin levels in the bloodstream?

Life’s Responsiveness

If a bog plant designed to catch insects proves unable to do so, the result will be starvation for ____________.

Why does a living thing need to be responsive?

Based on Figure 11.5 in your text, what is the role of homeostatic mechanisms?

When an environmental change shifts an organism’s internal chemistry toward a new state, the organism’s response is to try to return its chemistry toward the original state. This tendency on the organism’s part is called ____________.

Responsiveness at the Transcriptional Level

In the lactose operon of E. coli, what causes the repressor protein to change its shape?

What is the resultant effect of the repressor protein’s shape change on lactose gene expression?

When there is little or no lactose present in a bacterium’s environment, then the gene for the lactose transport enzyme is not trans-____________ and trans-____________.

When there is little or no lactose present in a bacterium’s environment, then the gene for the ____________ breakdown enzyme is not transcribed and translated.

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.

When there is little or no lactose present in a bacterium’s environment, then the ____________ operon is shut down.

When the lactose operon is functioning, the bacterium can ____________ and break down lactose because ____________ and degradation genes are being transcribed.

Responsiveness at the Cellular Level

After a fly trips the sensory hair on the modified leaf of a Venus flytrap, what is the very next step in the closing process?

According to Figure 11.10, list the complete sequence of chemical events in the closure of a Venus flytrap.

In the Venus flytrap, 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.

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 ____________.

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 ____________ secretion of 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.

What is the general effect of decreasing melatonin levels in the body?

List 5 different reasons some individuals take a melatonin supplement.

Informational Continuity in Organisms

Biological information is preserved within the base sequence of what molecule?

Reproduction: Asexual and Sexual

Asexual Reproduction

Give 3 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?

Sexual Reproduction

One major advantage of sexual reproduction over asexual reproduction is that in sexual reproduction, the population has increased ____________ variability.

List 4 disadvantages of sexual reproduction.

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 from two separate ____________, or two similar collections of genes arranged on two complete sets of ____________.

Preparing Reproductive Cells for Multicellular Organisms

The Challenge of Making a Reproductive Cell

A reproductive cell must differ genetically from other normal body cells in what critical way (because it will soon fuse with another reproductive cell to form a new individual)?

How Can This Ploidy Problem Be Solved?

The specialized process that halves the number of chromosomes during sex cell formation is named ____________.

Meiosis: A Triumph of Genome Reduction and Genetic Variability

List in order 8 successive stages in the process of meiosis.

The stage of meiosis in which the total number of chromosomes is reduced to half is called the reduction division. Which stage 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 ____________.

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.

Early in your own development there exists a small subset of diploid cells called primary germ cells. Where do they begin to develop? 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?

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 ____________.

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.

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

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 ____________.

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

Spermatogenesis and Fertilization

Sperm cell production occurs within the interior lining of the ____________.

Using Figure 12.21, list in order the sequence of cell types that produce a sperm cell.

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.

Penetration of the egg’ zona pellucida by the sperm cell is a process driven by the activity of a(n) ____________.

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.

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?

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

Name a birth control method that is primarily contraceptive and secondarily abortive in its effects.

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 terms did he use? When did he consider human life to begin?

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

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.

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.)

Destruction of Human Life Takes Various Forms

What chemical combination is commonly used to terminate a pregnancy, killing the little one?

Briefly describe a common surgical procedure for aborting a little one.