When stem cells called spermatogonia divide, one differentiates into a primary spermatocyte, What happens to the second daughter cell?
It remains in the outer layer of the seminiferous tubule
Which of the following occurs during the process of spermiogenesis
Spermatids differentiate into mature sperm
Which of the following is not a function of sustencular cells?
Produce androgens, particularly testosterone
Colostrum contains ____ than breast milk.
More proteins and less fat
At puberty, what change occurs in the cardiovascular system of males?
Stimulation of erythropoiesis
If you are homozygous for a trait (such as curly hair), what does that mean for your phenotype?
You will express that trait
What is the composition of the filtrate in the capsular space?
Similar to plasma, only no proteins
Why is the presence of microvilli important to the epithelial tissue of the PCT?
Because reabsorption is occurring
How is you genotype distinguished from your phenotype?
Genetic makeup/anatomical and physiological characteristics of an individual
Which of the following traits is inherited in a codominant fashion? What does codominant mean?
Type AB blood type/Both dominant and recessive traits are equally expressed
If one parent is homozygous dominant for a trait (ZZ)and the other parent is homozygous recessive for the same trait (zz), what is the outcome in their offspring?
A and B are correct
If a mother is a carrier for colorblindness (XCXc) and a father is colorblind (XcY), what is the chance for colorblindness in their female progeny?
1/2 will be colorblind, XcXc
Why are children not identical copies of their parents?
All of the above are factors
How is the generation of four sperm possible from one spermatogonium
Meiosis I yields two haploid secondary spermatocytes, which go through meiosis II and become four haploid spermatids
If secretions from the prostate gland are absent from semen, how does the composition of semen change?
Its pH is higher and its volume decreases by about 30%
What nephron structures are involved in filtration?
Glomerular capillaries, lamina densa, and filtration slits of the podocytes
What is the role of capsular hydrostatic pressure (CsHP)?
Pushes water and solutes out of filtrate into plasma
What direct affect does sympathetic activation have on GFR?
Produces powerful vasoconstriction of the afferent arteriole
Where is concentration of urine the greatest? Why?
In the medulla/concentrating mechanism relies on osmosis
If a male has his prepuce surgically removed, what has happened to him?
He has been circumcised
What will happen to the penis if the arteries withing the penis dilate?
The male attains an erection
What is a direct effect of low FSH secretion in males?
The rate of sperm production decreases
All of the following except ____ are effects of angiotensin II
Inhibition of ADH release
How long does it take for a sperm to reach ovum? Why?
30 minutes to 2 hours/contraction of uterine musculature and ciliary action assist sperm travel
What important role do hyaluronidase and acrosin play in fertilization?
Penetration of the zona pellucida
What process of chemical interplay among developing cells prompts the differentiation of other embryonic cells?
Induction
Which of the three embryonic germ layers consists of cells that do not migrate to the interior of the inner cell mass?
Ectoderm
Which body system develops form all three embryonic germ layers?
Endocrine system
What is the developmental fate of the inner cell mass of the blastocyst?
It becomes an embryo
Improper development of which of the extraembryonic membranes affects the cardiovascular system?
Yolk sac
How would the absence of juxtamedullary nephrons affect the volume of urine and its osmotic concentration?
Increase volume; decrease osmotic concentration
Which structures move with the testes during their descent from the abdomen?
Ductus deferens, testicular artery, lymph vessels, and nerves
The mechanism that establishes the medullary osmotic gradient depends most on the permeability properties of the ____.
Nephron loop
Which of the following is not associated with the renal corpuscle?
a vasa recta
An increase in the permeability of the cell of the collecting tubule to water is due to a(n) ___.
increase in the production of ADH
The urinary bladder is composed of ____ epithelium.
transitional
The kidneys are stimulated to produce renin ___.
by a decrease in the blood pressure
Which of the choices below is not a function of the urinary system?
eliminates solid, undigested wastes and excretes carbon dioxide, water, salts, and heat
The mechanism of water reabsorption by the renal tubules is _____.
osmosis
Most electrolyte reabsorption by renal tubules is ___.
hormonally controlled in distal tubule segments
The macula densa cells respond to ___.
changes in solute content of the filtrate
Which of the following is not reabsorbed by the proximal convoluted tubule?
creatinine
The fluid in the glomerular (Bowman's) capsule is similar to plasma except that it does not contain a significant amount of ___.
plasma protein
Which of the following hormones is important in the regulation of sodium ion concentrations in the extracellular fluid?
aldosterone
Atrial natriuretic peptide is a hormone that is made in the atria of the heart. The influence of this hormone is to ___.
reduce blood pressure and blood volume by inhibiting sodium and water retention
Respiratory acidosis can occur when ___.
a person's breathing is shallow due to obstruction
Total body water is not a function of which of the following?
amount of water ingested
Which of the choices below is not an essential role of salts in the body?
anabolism of lipids
Which of the choices below exerts primary control over sodium levels in the body?
aldosterone
The fluid link between the external and internal environment is ___.
plasma
Newborn infants have relatively higher ____ content in their ECF than do adults.
sodium
Which of the following hormones controls the release of anterior pituitary gonadotropins?
GnRH
The "master switch" for male reproductive development is ____.
the SRY gene
The primary function of the uterus is to ____.
receive, retain, and nourish a fertilized ovum
Why is the blood-testis barrier important?
because spermatozoa and developing cells produce surface antigens that are recognized as foreign by the immune system
The structures that receive the ovulated oocyte, providing a site for fertilization, are called the _____.
fallopian tubes
If gametes were diploid like somatic cells, how many chromosomes would the zygote contain?
twice the dipliod number, and with every succeeding generation, the chromosome number would continue to double and normal development would not occur
Human egg and sperm are similar in that ____.
they have the same number of chromosomes
The constancy of the chromosome number from one cell generation to the next is maintained through ___.
meiosis
Fertilization generally occurs in the ___.
Fallopian tubes
Spermiogenesis involves the ____.
formation of a functional sperm by the stripping away of superfluous cytopasm
Which of the following female structures is homologous to the male scrotum?
labia majora
In humans, separation of the cells at the two-cell state following fertilization may lead to the production of twins, which in this case would be ___.
identical
How do the testes respond to exposure to excessive body warmth?
They move away from the pelvic cavity
Effects of estrogen include ____.
growth of the breasts at puberty
Secretion of progesterone stimulates ____.
preparation of the mammary glands for lactation
Which of the following statements about sperm is not true?
The sperm midpiece consists of mitochondria spiraled tightly around the contractile filaments of the tail
The cells that produce testosterone in the testis are called ____.
interstitial endocrine cells
The testicular cells that construct the blood-testis barrier are the ___.
sustentocytes
Which of the following statements is true concerning the mammary glands of both males and females?
the mammary glands are modified sweat glands that are actually part of the integumentary system
Normally menstruation occurs when ___.
blood levels of estrogen and progesterone decrease
The basic difference between spermatogenesis and oogenesis is that ___.
in oogenesis, one mature ovum is produces and in spermatogenesis four mature spermare produced from one parent cell
Occasionally three polar bodies are found clinging to the mature ovum. One came from an uequal division of the ovum, but from where did the other two arise?
The first polar body has also divided to produce two polar bodies
Which of the following will occur after ovulation?
The endometrium enters its secretory phase
Which of the following is not a germ layer?
epiderm
The formation of endodermal and ectodermal germ layers occurs at ____.
gastrulation
Which hormone maintains the viability of the corpus luteum?
human chorionic gonadotropin
Which of the following events does not occur during the first 8 weeks of development?
myelination of the spinal cord
Which of the following is not a correct matching of a fetal structure with what it becomes at birth?
ductus arteriosus - ligamentum teres
Which body system of a pregnant woman undergoes the most dramatic physiological changes during pregnancy?
cardiovascular system
A premature separation of the placenta from the uterine wall is called ____.
abrupto placenta
The correct sequence of preembryonic structures is ____.
zygot, morula, blastocyst
Those characteristics that can be determined on superficial inspection of an individual are known as ___.
phenotypic
Is genetic diversity due entirely to inherited genes on the sex chromosomes?
No, because genetic diversity has nothing to do with the sex chromosomes but is due to crossing-over of chromosomes, independent assortment of chromosomes, and segregation of chromosomes
A female infant is born with several hundred oocytes, each one genetically unique. This is due to ____.
independent assortment and random crossover
In meiosis the spermatozoa that are produced are genetically unlike each other and unlike the cell that produces them. This is one reason for the great variation among humans. What cause this effect?
crossing-over and independent assortment only
The reason recessive genetic disorders are more frequent than disorders inherited as dominant it that ____.
carriers are not eliminated by the disease before passing the defective alleles on to their offspring
The gene responsible for the condition known as sickle-cell anemia demonstrates _____.
incomplete dominance
An example of multiple-allele inheritance is ____.
the ABO blood group
Which of the following is true concerning environmental influence on genetic expression?
drugs and nutrition can alter normal gene expression
Sex chromosomes of a normal male are ____.
XY
A woman has blond hair and brown eyes. This statement is best described as indicating ____.
phenotype
Alcohol acts as a diuretic because it ____.
inhibits the release of ADH
The function of angiotensin II is to ____.
constrict arterioles and increase blood pressure