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.