Reproduction and Development
Not form a placenta
A blastocyst without a trophoblast would
The lack of genetic variability puts them at risk in changing environments
A disadvantage of asexual reproduction is that
Cleavage
A fertilized egg undergoes cell division without further growth in the process called
Lower temperature
A functional advantage of having human testes in the scrotum rather than in the abdomen is
hCG; trophoblast
A pregnancy test is based on the production of ___ by the ____.
Males produce many more sperm than females produce eggs
A single egg is evolutionarily more precious than a single sperm because
Increase the evolutionary fitness of the species
According to the grandmother hypothesis, human women live beyond their reproductive years to
Differentiates into the corpus luteum
After ovulation, the ruptured follicle
B. Since an unborn infant gets priority on blood nutrient pools, pregnancy during famine will likely be fatal for both mother and offspring; this mechanism reduces this risk and increases survival.
Although estrogen is primarily produced by ovaries, it is also produced by the adrenal glands and in fat tissue. Loss of the normal amount of fat lowers the level of estrogen so that the menstrual cycle and ovulation stops. Female Olympic athletes who train severely often shut off their cycles. What would be a reasonable evolutionary cause of this shutdown? A. This mechanism shifts use of energy from reproduction to life activities for staying alive. B. Since an unborn infant gets priority on blood nutrient pools, pregnancy during famine will likely be fatal for both mother and offspring; this mechanism reduces this risk and increases survival. C. The adrenal glands have evolved to produce fight-or-flight responses and natural selection has shifted them to this function and away from estrogen. D. Less food would result in less hormone production.
C. The cycle requires minimal threshold of estrogen and although the ovaries produce their regular levels, the loss of body fat would lower the estrogen level to below the threshold, thus shutting down the menstrual cycle.
Although estrogen is primarily produced by ovaries, it is also produced by the adrenal glands and in fat tissue. Young female athletes who train strenuously often find that their menstrual cycle shuts down. What would be a reasonable direct cause of this shutdown? A. The increased need for ATP for the muscle cells deprives ATP for ovaries. B. The increased use of ATP for muscles deprives ATP needed by the brain where the hypothalamus and pituitary control the menstrual cycle. C. The cycle requires minimal threshold of estrogen and although the ovaries produce their regular levels, the loss of body fat would lower the estrogen level to below the threshold, thus shutting down the menstrual cycle. D. Physical trauma to the ovaries themselves would shut down their estrogen production.
Fallopian tube
Another name for the oviduct is the
Small levels of estrogens are produced by the adrenal glands and fat tissue; with the lack of testosterone, a body develops along female patterns.
Castrating prepubescent bulls causes them to grow in female proportions because
14th day
During a 28-day uterine cycle, ovulation usually occurs on the
Fourth
During the ____ month, the fetal heartbeat is first loud enough to be heard by a physician with a stethoscope.
Blastula
During the formation of an embryo, a hollow sphere of cells with a fluid-filled cavity inside is termed a
No cell growth
Early cell division leading to the morula is characterized by rapid cell division and
FSH and LH
Female birth control pills act by inhibiting the production of
Abdominal cavity
Fertilization in humans normally occurs in the
The oviduct
Fertilization in humans occurs in which of the following structures?
Lanugo
From months 5 to 7, a fetus is covered in a fine down called
When the first sperm fuses with the egg membrane, it causes the membrane to depolarize and also separates the fertilization membrane and this gap forms a barrier to any other sperm
Generally only one sperm fertilizes an egg because
Half the
Haploid cells have ________ number of chromosomes as diploid cells.
Enzymes in the acrosome dissolve the zona pellucida
How does a sperm penetrate an egg?
Small tubules lined with developing sperm.
If we cut a cross-section through the testes, we would see
Second week
Implantation occurs during the
Yolk sac
In human development, the ______ is the site of early blood cell formation for the fetus.
Egg is fertilized
In human females meiosis is completed when the
Mitosis
In humans, males have a continuous supply of germ line cells because those cells regularly go through
Pituitary
In the human female, estrogen and progesterone exert feedback control over the
28 days
In the human female, the uterine cycle is an average
Seminiferous tubules
In the human male, sperm cells are produced in the
Urethra
In the human male, the tube used to carry both sperm and urine is the
Controls production of testosterone
LH is an abbreviation for luteinizing hormone, which is present in both males and females. In the male, LH
Corpus luteum to produce progesterone
LH stimulates the
interstitial cells; testosterone
LH stimulates the ______ of the testis to produce ______.
Men produce new sperm every day, while women are born with their life's allotment of eggs
Men can produce healthy sperm longer than women can produce healthy eggs because
Progesterone and estrogen levels are both declining
Menstruation begins because
prolactin; anterior pituitary
Milk production is triggered in breasts following several days of ____ production by the ____.
Protects the first trimester fetus from toxins
Morning sickness may be an evolutionary advantage because it
Inductive signals
Morphogens are examples of
They have different gene expression patterns
Nerve cells and skin cells from an individual are different functionally and structurally. These two types of cells from the same person are different because
The developing embryo implants itself in the endometrium
Pregnancy occurs when
HCG
Pregnancy tests detect the presence of ______ in the urine.
Testosterone
Secondary sexual characteristics in the male are directly maintained by the hormone
Prostaglandins
Seminal fluid contains _____, chemicals that cause the uterus to contract.
Maintenance of genetic variability
Sexual reproduction is necessary for
Epididymis
Sperm mature within the
Chorion
The _____ develops into the fetal portion of the placenta.
Chorion
The _____ is responsible for gas exchange in the egg of a chicken.
Yolk sac
The _______ provides nourishment for the embryo during chick development.
Expulsion of the placenta and membranes.
The afterbirth refers to the
Are analogous to the umbilical blood vessels in humans.
The allantoic blood vessels
Blastula
The blastocoel is formed during the _____ stage of development.
Fructose sugar in the surrounding seminal fluids added by the seminal vesicles.
The energy source for sperm to swim comes from
First
The fetus is most sensitive to the detrimental effects of alcohol during the ________ trimester.
Scrotum
The glans clitoris in the female is homologous to the ____ in the male.
oxytocin; hypothalamus
The hormone ____ from the ____ causes mammary lobules in the breast to contract, causing milk to flow.
Endometrium
The lining of the uterus that is discharged during the menstrual phase is the
E. fimbriae
The male reproductive system includes all EXCEPT which of the following? A. testes B. epididymis C. penis D. prostate E. fimbriae
B. interstitial cells
The male sex hormones are secreted by which of the following? A. spermatids B. interstitial cells C. vas deferens D. prostate
Placenta
The organ that exchanges molecules between fetal and maternal blood is the
Both fetal and maternal tissue.
The placenta develops from
Yolk sac
The sac that surrounds the fetus and usually ruptures just before childbirth is the
Third or fourth
The sex of the fetus can be first determined in the ______ month of development.
Vesicular (Graafian) follicle
The structure from which an egg is released during ovulation is called a(n)
Seminiferous Tubules → Epididymis → Vas Deferens → Urethra
Trace the correct path of the sperm during ejaculation.
Vagina → Cervix → Uterus → Oviduct
Trace the path of the sperm through the female reproductive tract.
Testosterone and Estrogen
What hormones influence the development of the secondary sexual characteristics of female?
Support and regulate the spermatogenic cells
What is the function of the Sertoli cells in the male reproductive tract?
vas deferens—carries urine
Which association concerning structures in the human male is incorrect? A. testes—produce sperm B. vas deferens—carries urine C. prostate gland—seminal fluid D. urethra—conducts sperm E. seminal vesicle—seminal fluid
A. oxytocin
Which of the following hormones causes the uterus to contract? A. oxytocin B. estrogen C. progesterone D. testosterone E. prolactin
B. acrosome
Which of the following is NOT a barrier to the sperm entering the egg? A. zona pellucida B. acrosome C. follicle cells D. the egg's plasma membrane
B. formation of the germ line cells
Which of the following is NOT a characteristic of childhood development? A. development of speech B. formation of the germ line cells C. increasing brain weight D. rapid growth
B. gastrulation
Which of the following is NOT a contraceptive? A. barriers that prevent sperm from entering the uterus B. gastrulation C. sterilization D. hormones that suppress ovulation
D. production of fat
Which of the following is NOT associated with the first trimester of fetal development? A. development of the sex organs B. rapid differentiation into the three tissue layers C. production of germ line cells D. production of fat
E. LH
Which of the following is responsible for controlling the production of male sex hormones? A. testosterone B. progesterone C. GnRH D. FSH E. LH
B. genetic recombination
Which of the following occurs during sexual reproduction but NOT during asexual reproduction? A. production of offspring B. genetic recombination C. cell division D. parthenogenesis
A. amniotic fluid
Which of the following serves as an insulator for the embryo? A. amniotic fluid B. allantois C. chorion D. primitive streak E. yolk sac
D. They are made of differentiated cells.
Which of the following statements about the three embryonic tissue layers is true? A. They are present in the morula. B. The cells of one layer are genetically different from the cells of another layer. C. All three layers develop into the same set of tissues. D. They are made of differentiated cells.
D. A surge of FSH promotes ovulation.
Which of the following statements is incorrect? A. The follicles in the ovary produce estrogen. B. The corpus luteum produces progesterone. C. placenta produces both estrogen & progesterone. D. A surge of FSH promotes ovulation.
C. Birth control pills have other health benefits in addition to preventing pregnancy.
Which statement about contraceptives is true? A. It is not necessary to follow the directions for taking the Pill for it to be 100 percent effective. B. Condoms prevent the transmission of sexually transmitted diseases but do not prevent pregnancy. C. Birth control pills have other health benefits in addition to preventing pregnancy. D. All contraceptives prevent the transmission of sexually transmitted diseases.
D. Maternal and fetal blood mix with each other.
Which statement is NOT correct about the placenta? A. Oxygenated blood flows to the fetus via the umbilical vein. B. Fetal blood flows to the placenta via the umbilical artery. C. Oxygen and nutrients go to the fetus from the maternal circulatory system. D. Maternal and fetal blood mix with each other.
Pituitary
Which structure in humans produces FSH?
The pituitary detects high levels of testosterone in the bloodstream and reduces FSH and LH.
Why do testes shrink when male athletes take synthetic steroid testosterone hormones?