Chapter 46: Reproduction (Mastering Biology & Dynamic Study Module)
Seasonal changes can be important to reproduction because ___________.
- Availability of resources to invest in gestating offspring can vary with season - Environmental stresses that could affect offspring survival can vary with season - Migration and other seasonal movement patterns can affect the possibility of finding a mate - Availability of resources on which young can feed can vary with season ALL OF THE LISTED RESPONSES ARE CORRECT
Which statements correctly explain how the hormone-based contraceptives affect the female reproductive cycle? Select all that apply.
- The low dose of estradiol in the combination pill prevents the surge in LH production - The progestin in the progestin-only pill causes changes in the endometrium that prevent implantation - The low doses of progestin and estradiol in the combination pill have a negative feedback effect on the hypothalamus, blocking ovulation.
Ovulation usually occurs on or about day _____ of a 28-day ovarian cycle.
14
In the human female ovarian cycle, ovulation is triggered by a sharp rise in luteinizing hormone (LH). What is the cause of this sharp rise?
A rise in estradiol from the follicle
The flowchart below describes the events of the ovarian cycle. Drag the names of the hormones to their appropriate locations on the flowchart, starting with the release of a hormone from the hypothalamus. Labels may be used once, more than once, or not at all. (Note: GnRH = gonadotropin-releasing hormone; LH = luteinizing hormone; FSH = follicle-stimulating hormone.)
A: GnRH B: LH and FSH C: Estradiol D: LH and FSH E: Estradiol and progesterone F: LH and FSH G: Estradiol and progesterone
At what point does the secondary oocyte complete meiosis?
After the sperm penetrates the oocyte
From a single cell, oogenesis in a mammal will produce __________.
An egg and two or three polar bodies
A hermaphrodite is ___________.
An individual with both male and female reproductive systems
Which hormone(s) is(are) directly responsible for triggering the development of the secondary sex characteristics of males, such as beard growth?
Androgens
Sort the following secondary sex characteristics and hormones based on whether they are related to androgens, estrogens and progesterone, or neither. Drag each phrase to the appropriate bin.
Androgens: - Development of facial hair - Testosterone - Deepening of voice - Increased muscle mass - Increased aggressiveness Estrogen and Progesterone: - Fat deposition in hips - Estradiol - Increased water retention - Breast development - Changes in calcium metabolism Neither: - Blank
Which of the following statements about oogenesis in humans is true?
Beginning at puberty, a primary oocyte completes its first meiotic division to form a secondary oocyte and a polar body approximately every month
How does spermatogenesis differ from oogenesis?
Diploid cells give rise to four functional gametes in spermatogenesis
Sperm become capable of movement while in the _____.
Epididymis
If there is no fertilization, degeneration of the corpus luteum results in a drop in _____, which results in the sloughing off of the uterus's endometrium.
Estrogen and progesterone
After ovulation, high levels of _____ inhibit _____ secretion.
Estrogen and progesterone... FSH and LH
Developing ovarian follicles primarily secrete _____.
Estrogens
Which of the following choices correctly lists the four phases of the sexual response cycle in their proper sequence?
Excitement, plateau, orgasm, and resolution
Which pituitary secretion stimulates sperm production?
FSH
True or false? The production of sperm begins at puberty when spermatogonia undergo meiosis I to form primary spermatocytes, which then undergo meiosis II to form secondary spermatocytes. These secondary spermatocytes go on to form spermatids, which mature into sperm cells.
False
An ovarian follicle undergoes several changes during the human female's menstrual cycle. Which of the following sequences is correct, beginning with the oocyte?
Follicle development, ovulation, and corpus luteum development
What products are formed when a diploid cell undergoes meiosis?
Four haploid cells
Which of the following is a means of sexual reproduction?
Fusion of egg and sperm
Pheromones are __________.
Generally effective at very low concentrations
Which part of the human sperm carries a haploid set of chromosomes?
Head
If there is fertilization, secretion of _____ by the early embryo maintains the corpus luteum.
Human Chorionic Gonadotropin
Which reproductive method is the most prevalent in mammals?
Internal fertilization
What is an advantage of internal fertilization?
Internal fertilization can occur outside of aquatic or marine habitats.
Which pituitary secretion stimulates the testes to secrete androgens?
LH
What is the relationship between Leydig cells and Sertoli cells?
Leydig cells stimulate the production of sperm cells, and Sertoli cells nourish developing sperm.
A rapid increase in the _____ level stimulates ovulation.
Luteinizing hormone
Which of the following is an accurate statement concerning mating behavior in asexually reproducing species?
Mating behavior is a stimulus that can help to bring about ovulation in asexually reproducing species.
Which of the following is an accurate statement about sexual reproduction?
Most animals produce offspring by sexual reproduction.
The secretion of androgens is regulated by a _____ feedback mechanism involving the _____ and _____.
Negative...Hypothalamus...Pituitary Gland
Which of the following is a difference between the reproduction of humans (and other primates) and the reproduction of all other mammals?
Only humans (and other primates) have menstrual cycles.
In mammals, meiosis to produce the female egg cell is initiated in the __________.
Ovary
Immediately after ovulation, an egg is collected into the __________.
Oviduct
What is the usual site of the fertilization of an egg cell?
Oviduct
Which of the following is an accurate statement about parthenogenesis?
Parthenogenesis appears rarely in vertebrates.
Which of the following is the least effective method of birth control?
Rhythm method
Vestibular (Bartholin's) glands __________.
Secrete lubricating fluid
Which of the following is not a function of the placenta?
Secreting hCG
Which of the following is the correct path that sperm travel when leaving the body of a human male?
Seminiferous tubule; epididymis; vas deferens; ejaculatory duct; urethra
Sperm develop in the _____.
Seminiferous tubules
Select the correct statement about reproduction and eukaryotic life cycles.
Some animal adults are haploid
Individuals clustered in the same area that release their gametes into the water at the same time are engaging in __________.
Spawning
Some insect females are able to store sperm in __________ until environmental conditions are favorable for the development of their offspring.
Spermathecae
Which diploid cells are produced by an embryonic germ cell?
Spermatogonia
Which of the following is the correct sequence of stages in the development of sperm during the process of spermatogenesis?
Spermatogonial stem cell; spermatogonium; primary spermatocyte; secondary spermatocyte; early spermatid; sperm cell
The human female's external reproductive structures are ___________.
The clitoris, two sets of labia, and vaginal opening
The "two-fold" cost of sex refers to ___________.
The lower number of reproductive offspring produced by individuals of species that have two sexes
Birth control pills contain synthetic estrogen and progesterone. How do these hormones prevent pregnancy?
They inhibit the pituitary from secreting FSH and LH, preventing ovulation.
What role do germ cells play in gametogenesis?
They produce cells that divide by mitosis and then undergo meiosis to form gametes
True or false? Humans form gametes by a process called gametogenesis.
True
Sperm exit a male's body via the _____.
Urethra
Which structure is part of the excretory and reproductive systems in males?
Urethra
A fertilized egg usually implants itself and develops in the _____.
Uterus
