Biology 3000 Chapter 50-53

Neural crest cells at the dorsal surface of the neural tube

migrate to many different regions of the body.

You are currently studying the behavior and physiology of a vertebrate about which little is known. Based on what you know about other vertebrates, what would you predict would be the state of this animal when it was not in the fight or flight state.

Leptin levels are increased to enhance appetite.

The fact that regeneration is a common type of reproduction in sea stars suggests tha

adult sea star cells retain the mechanism to form a complete animal.

Spina bifida occurs due to a defect in the development stage

after gastrulation.

In a mammal that you are studying, blood sodium levels are decreasing sharply. To correct this problem, which hormone might you try to administer?

aldosterone

This is a water-soluble hormone derived from the nervous system that regulates blood volume and blood pressure.

antidiuretic hormone

In female mammals, germ cells

are arrested in meiosis I until puberty

If you had to increase hormonal secretions in a test subject, but you did not want to affect sodium levels, which two hormones could you use?

atrial natriuretic peptide and aldosterone

The two primary mechanisms of cell differentiation are conditional specification and

autonomous specification.

Unlike all other amine derived hormones, thyroid hormones

bind to intracellular receptors rather than to membrane-bound receptors to elicit a response.

The outcome of cleavage during embryonic development is the production of a

blastula.

Gonadotropin-releasing hormone regulates

both follicle-stimulating and luteinizing hormones as well as steroid production by the gonads.

What structures of the male and female reproductive systems do not share a common embryonic origin?

cervix and ejaculatory duct

Children born with fetal alcohol syndrome have

cognitive disorders

. When a planarium is cut in half, a head will regenerate from the wounded anterior end and a tail will regenerate from the wounded posterior end. This is an example of

conditional specification.

Sexually transmitted diseases are a major cause of infertility. Knowing this, what method of birth control would you think is best for reducing infertility rates

condoms

To mobilize more glucose during fasting,

cortisol, epinephrine, and glucagon will all increase

Cells destined to develop into muscle tissue are transplanted to an area where cells are destined to become epithelial cells. If these cells are under autonomous specification what will happen? The cells will

develop into muscle tissue.

Thyroid hormone is to amphibian metamorphosis as this compound is to insect molting.

ecdysone

An amine hormone important in the stress response in vertebrates is

epinephrine.

Sex differences in body growth are mediated by changes in growth hormone, insulin-like growth factor I and

estradiol and testosterone.

. Which of the following represents the proper order of events in embryonic development?

fertilization, cleavage, gastrulation, neurulation, organogenesis

Which of the following is TRUE of fate mapping?

It determines the ultimate structure/function of a particular cell type during embryonic development.

Stem cells (unspecialized cells) that develop into bone cells have undergone which type of process?

Cellular differentiation

Which of the following is TRUE of cell cleavage?

It involves consecutive cycles of cell division without cell growth and forms a blastula

Which of the choices lists the three phases of the ovarian cycle in the correct order?

follicular, ovulation, luteal

Which hormone is inhibited by hypothalamic somatostatin and can be used to treat short stature in children?

growth hormone

Insulin-like growth factor I is produced in response to

growth hormone.

Which event of fertilization occurs first?

he acrosomal reaction

In mammals, gestation is defined physiologically as the time from _____ to birth.

implantation

The stage of development that involves cell division without cell growth is

Cleavage

. Hans Spemann and Hilde Mangold conducted pioneering experiments in which they transplanted the dorsal lip of the blastopore in an early gastrula newt to the ventral side of another early gastrula newt. What was the outcome of this experiment?

Discovery of Spemann's organizer. The development of dorsal structures (neural tube, notochord) on both the dorsal and ventral parts of the gastrula that received the transplant. Identification of a morphogenic field in the dorsal lip of the blastopore of an early gastrula. Discovery of a group of embryonic cells in the dorsal lip that ultimately produce specific body structures.

What would be most likely to occur if one of a man's testicles failed to descend (drop into the scrotum)

He would have a lower than normal sperm count.

In humans, nitric oxide is an important gaseous neurotransmitter. Nitric oxide is synthesized by three isoforms of nitric oxide synthase (NOS). What would be a likely effect if a male were missing the gene that codes for one of the NOS isoforms?

He would have difficulty getting and/or sustaining an erection.

Thalidomide, an anticonvulsive and antihistamine medication, was shown to cause severely deformed limbs in children whose mothers took the medication. What might thalidomide do during development?

Impair morphogenetic fields within the embryo.

Which of the following is TRUE of fertilization?

It both restores the egg to a diploid state and activates cell division.

Cell cleavage during embryonic development in ducks is

meroblastic.

Which of the following germ layer-structure is mismatched?

mesoderm-digestive tract

The specific process by which a caterpillar becomes a butterfly is called

metamorphosis.

The central nervous system first forms during

neurulation.

The first group of cells to migrate through the blastopore will become

notochord.

External fertilization

occurs in amphibians. often leaves fertilized eggs susceptible to predation. involves the release of eggs and sperm into a body of water. requires specialized behavior.

Fertilization of an ovum normally occurs in the

oviduct

Fertilization of human eggs usually takes place in the

oviduct.

This hormone is secreted from the posterior pituitary and regulates muscle contraction.

oxytocin

Which of the following hormones stimulates uterine contractions during the birth process in mammals?

oxytocin

The act of nursing stimulates the contraction of smooth muscle cells in the breast. If a newborn infant is unable to nurse, then

oxytocin is not secreted

Often it is important for health reasons to induce labor (i.e., smooth muscle contractions) in pregnant women. The drugs used for this purpose would most closely resemble

oxytocin.

Which hormones counteract each other in regulating calcium homeostasis?

parathyroid hormone and vitamin D (1,25 dihydroxyvitamin D)

What would result if more than one sperm fertilized an egg?

polyploidy

In a frog embryo, gastrulation

proceeds by invagination and involution as cells roll over the dorsal lip of the blastopore.

If pregnancy does not occur, what hormome will decrease in concentration?

progesterone

Maintenance of the uterine lining during pregnancy in mammals requires

progesterone.

What hormone regulates milk production in mammals?

prolactin

In lactation, milk production is stimulated by _____, while milk release is stimulated by _________.

prolactin, oxytocin

17. What are the three glands that produce the liquid portion of semen?

prostate, seminal vesicles, bulbourethral

Which of the following lists the structures of the male reproductive tract in the proper order from sperm production to ejaculation?

seminiferous tubules, epididymis, vas deferens, ejaculatory duct, urethra

The ectoderm is to the central nervous system as the mesoderm is to the

skeletal muscle

All types of internal fertilization require

specialized anatomical structures.

. What environmental factor might lead to year-round, rather than seasonal, reproductive activity?

stable food supplies

A physician has a young man as a patient who does not seem to be developing male secondary sex characteristics. Predict which hormone the physician could prescribe to help this issue.

testosterone

Development of all the structures listed below occur during neurulation EXCEPT:

the archenteron.

The inability of a man to produce LH would result in

the inability of Leydig cells to produce testosterone.

Which of the following is likely required to initiate cell differentiation during development?

the presence of mRNAs that express cell-specific proteins

What type of contraception is the least effective?

the rhythm method

An endocrine gland is

the site at which hormones are produced and released into the blood.

Erection occurs when

the spongy erectile tissue of the penis becomes engorged with blood. the veins flowing out of the penis vasoconstrict. . the arteries of the penis vasodilate. nitric oxide is released.

The cortical reaction causes

the zona pellucida or vitelline layer to harden.

In what order do sperm move through the structures of the female reproductive tract?

vagina, cervix, uterus, oviduct

The process by which cells acquire specialized forms and functions is called

cell differentiation.

What cell is haploid?

ovum

Which of the following is NOT a morphogen?

Cadherin

You are examining a laboratory subject in which blood calcium levels are rising. Predict the consequences for this individual.

. Blood parathyroid hormone levels would decrease.

Through studies using the animal cap assay this morphogen was shown to be important for the determination of the different types of mesoderm tissue in the developing embryo.

. activin

Once an egg has been fertilized, what event(s) are crucial for preventing additional sperm from inserting chromosomes into the egg?

. both the cortical reaction and fast block to polyspermy

Organogenesis

Arises from germ layer cells

Which of these hormone-action pairs is mismatched?

Atrial natriuretic peptide-muscle contraction

Predict what would occur if the amount of sodium suddenly increases in the blood.

Both blood osmolarity would increase and aldosterone levels would decline.

What allows fetal hemoglobin to remove oxygen from maternal hemoglobin?

Fetal hemoglobin has a higher affinity for oxygen than does maternal hemoglobin

In chordates, which mesoderm structure forms during gastrulation and provides structural rigidity along the dorsal anterioposterior axis of the embryo?

Notochord

Dopamine derived from the hypothalamus is the prominent hormone controlling pituitary prolactin secretion. Dopamine inhibits prolactin secretion. What do you predict would happen if the pituitary were removed from the base of the brain and transplanted to some distant place in the body (for instance on top of the kidney), such that dopamine could no longer regulate prolactin secretion? You can assume that the transplanted pituitary will be exposed to a ready supply of blood vessels.

Prolactin secretion would increase.

What is true of the corpus luteum?

Secretions of the corpus luteum prepare the uterus for implantation of the embryo.

Which health problem(s) are due to environmental factors?

Spina bifida and fetal alcohol syndrome

Why is it important to have a slow block to polyspermy?

The slow block creates a permanent barrier.

What can be said about peptide hormones

They are water-soluble and bind membrane receptors to elicit a response on target cells

Your physician has requested a test that involves radioactive iodine. This material will be injected and monitored to watch for normal rates of uptake. Test results reveal that the rate of uptake is abnormal. Which hormone would you predict to be outside of a homeostatic range?

Thyroid hormone

Which of the following sequence of events of fertilization is in the proper order?

acrosomal reaction, binding of sperm to egg membrane, fast block to polyspermy, increase in egg cytosolic calcium, and then the slow block to polyspermy

An explanation for why an individual that is incapable of generating the fight or flight response would be abnormal function of this gland.

adrenal gland

Which of these gland-hormone pairs is mismatched?

adrenal-parathyroid hormone

Paland and Lynch showed that sexual populations possessed fewer deleterious mutations than asexual populations. These results supported the hypothesis that

in sexual reproduction, the reassorting of alleles allows for the elimination of more detrimental alleles than in asexual reproduction.

Parathyroid hormone's main function is to

increase calcium by mobilizing the ion from bone.

Sexual reproduction

increases genetic variation

Which of the following is TRUE of a morphogen? It is a signaling molecule that

induces the differentiation of cells within the embryo

A problem with the action or production of this substance leads to both type I and type II diabetes mellitus.

insulin

After you eat lunch, the nutrients in your food are released in the digestive process and eventually make their way into the blood. The rising nutrient levels quickly move beyond the standard homeostatic range. Normally, a hormone would be released at this time to regulate these nutrients. Imagine that in your case, that return to homeostatic levels does not occur. What hormone would you need to receive to return blood levels to normal?

insulin

This hormone does not play a role in the female reproductive system.

insulin

Imagine that your pancreatic function has been compromised. This has lead to your inability to maintain your blood glucose levels. Predict which two hormones your physician would administer to return you to homeostatic glucose levels.

insulin and glucagon

An animal that can fertilize its own eggs

is a synchronous hermaphrodite

If a mammalian species that lives in an area with harsh winters and mild springs and summers has a gestation length of five months, when would you expect mating to occur? Assume implantation and pregnancy immediately follow mating.

late fall

A person who has a constant need to eat may show impaired secretion of or response to

leptin.