18: Animal Reproduction Flashcards
Module 3, Lesson 7
____ involves meiosis and the fusion of haploid gametes to form a diploid zygote.
Sexual reproduction
Offspring produced through sexual reproduction are…
Genetically unique
____ involves mitosis and produces offspring that are genetically identical to the parent.
Asexual reproduction
____ is a form of asexual reproduction where females produce offspring from unfertilized eggs.
Parthenogenesis
____ are individuals with both testes and ovaries, capable of producing both eggs and sperm.
Hermaphrodites
____ can produce both eggs and sperm at the same time.
Simultaneous hermaphrodites
True or false:
Some animals that are simultaneous hermaphrodites still need a mate in order to reproduce.
True
____ can change sexes.
Sequential hermaphrodites
____ are animals that start off as females but can turn into males.
Protogynies
____ are animals that start off as males but can turn into females.
Protandries
Sex determination in many fish and reptiles is…
Temperature sensitive
Sex determination in mammals and birds is…
Genetic
In mammals, sex is determined by the…
Y chromosome
(specifically the SRY gene it carries)
True or false:
In birds, the female genotype is ZZ.
False
This is the male genotype ; the female genotype is ZW
In ____, eggs and sperm are released into the water and unite to form zygotes.
External fertilization
In external fertilization, the timing of ____ is critical.
Gamete release
In ____, male gametes are introduced into the female reproductive tract.
Internal fertilization
____ occurs when fertilized eggs are deposited outside the mother’s body to complete development.
Oviparity
____ occurs when fertilized eggs remain inside the mother’s body for development, and the young obtain all their nutrients from the egg.
Ovoviviparity
____ occurs when the young develop within the mother and obtain nutrients from her blood.
Viviparity
The ____ center around the periodic release of an egg.
Female reproductive cycles
Females with a(n) ____ are only receptive to males when in “heat” (around ovulation).
Estrous cycle
Females with a(n) ____ are receptive to males at any point during the cycle.
Menstrual cycle
Monotremes use ____ reproduction.
Oviparous
Marsupials use ____ reproduction, but the offspring are incompletely developed when born and finish development in the mother’s pouch.
Viviparous
Placental mammals use ____ reproduction, where fetal development is completed in the uterus.
Viviparous
True or false:
Compared to marsupials, placental mammals are more developed at birth.
True
In males, the ____ are the glands that produce gametes and hormones.
Testis
The testes are located outside the body in the ____, which keeps them at a cooler temperature that is optimal for sperm development.
Scrotum
The ____ is the location of sperm maturation and storage.
Epididymis
The ____ are the tubes that carry the sperm into the body cavity.
Vas deferens
Sperm leaves the body via the…
Urethra
____ are paired glands that add a fructose-rich fluid to the semen.
Seminal vesicles
Secretions from the ____ make up about 30% of semen.
Prostate gland
Secretions from the ____ make up about 10% of semen.
Bulbourethral glands
Spermatogenesis occurs in the…
Seminiferous tubules
____ facilitate sperm development.
Sertoli cells
____ are located near the outside of the tubules and produce primary spermatocytes.
Germ cells
Primary spermatocytes undergo meiosis to produce…
Haploid spermatids
Spermatids mature into…
Spermatozoa
____ are located between the seminiferous tubules and produce testosterone.
Leydig cells
____ is the major male sex hormone.
Testosterone
List the three functions of testosterone.
- Triggers generation of male genitalia during development
- Triggers development and maintenance of secondary sex characteristics
- Stimulates sperm production
The head of a sperm contains the…
Haploid nucleus and acrosome
The ____ is a vesicle containing enzymes to digest away the protective coating surrounding the egg.
Acrosome
The body of a sperm contains ____ that generate the ATP necessary for flagellar movement.
Mitochondria
List the five hormones involved in regulating male reproductive function.
- Gondatropic-releasing hormone (GnRh)
- Luteinizing hormone (LH)
- Follicle-stimulating hormone (FSH)
- Testosterone
- Inhibin
At puberty, the hypothalamus begins secreting ____, which stimulates the anterior pituitary.
this is the same in both males and females
GnRh
GnRh stimulates the anterior pituitary to secrete…
this is the same in males and females
LH and FSH
In males, the hormone LH…
Targets Leydig cells and triggers testosterone secretion
In males, FSH targets…
Sertoli cells in the seminiferous tubules
Testosterone exerts negative feedback on the secretion of…
LH
____ is released by Sertoli cells and exerts negative feedback on FSH secretion.
Inhibin
True or false:
In males, the blood plasma levels of testosterone, FSH, and LH are kept fairly constant.
True
In females, the ____ is the gland that produces gametes and hormones.
Ovary
The ____ connects the ovary to the uterus.
Fallopian tube
The ____ produced during ovulation travel down the fallopian tube.
Secondary oocytes
The fallopian tubes are also sometimes called…
Oviducts / uterine tubes
The ____ is a muscular organ that houses the developing embryo and fetus.
Uterus
The ____ is the narrow neck of the uterus that opens to the vagina.
Cervix
The ____ acts as both a repository for sperm and the birth canal during childbirth.
Vagina
In humans, oogenesis occurs in the…
Ovary
Germ cells in the ovary begin meiosis during…
Fetal development
The initial process of meiosis in female germ cells is stopped at…
Prophase 1
At birth, all potential ova have already begun meiosis and are located in the…
Follicles of the ovary
Starting from puberty, several follicles begin maturation at the beginning of each…
Menstrual cycle
True or false:
Multiple follicles completely mature during each menstrual cycle.
False
Only one will completely mature
The mature follicle that releases the secondary oocyte during ovulation is called a….
Graafian follicle
In oogenesis, the products of meiosis 1 are…
A secondary oocyte and a polar body
True or false:
In oogenesis, meiosis 2 will only occur if fertilization occurs.
True
In oogenesis, the products of meiosis 2 are…
The ovum and another polar body
In females, fertilization and meiosis 2 occur in the…
Upper third of the fallopian tube
List the six hormones involved in female reproduction.
- Gonadotropin-releasing hormone (GnRh)
- Luteinizing hormone (LH)
- Follicle-stimulating hormone (FSH)
- Estrogen
- Progesterone
- Human chorionic gonadotropin (hCG)
The first half of the ovarian cycle is called the…
Follicular phase
The maturation of a follicle is stimulated by…
LH and FSH
Ovulation is triggered by a surge in ____ halfway through the ovarian cycle.
LH
After ovulation, the remaining follicle cells become the…
Corpus luteum
The beginnning of the uterine cycle is defined by…
Menstruation
The ____ of the uterine cycle is stimulated and sustained by increased secretion of estrogen.
Proliferation phase
Estrogen is secreted from the…
Ovary
During the proliferation phase, estrogen targets the endometrium of the uterus and triggers…
Thickening of the uterine lining
After ovulation, the ____ secretes progesterone and estrogen.
Corpus luteum
Progesterone and estrogen target the endometrium and trigger…
Further thickening and secretion of the uterine lining
During the ____, the endometrium becomes much thicker in preparation for receiving an embryo.
Secretory phase
Progesterone and estrogen exert negative feedback on the secretion of…
LH and FSH
If fertilization does not occur, then the ____ disintegrates.
Corpus luteum
If no fertilization occurs, the levels of ____ and ____ decline, resulting menstruation.
Estrogen and progesterone
If fertilization does not occur, the secretion of GnRh….
Increases
If fertilization and implantation occur, the embryo will prevent regression of the corpus luteum by secreting…
Human chorionic gonadotropin
(hCG)
If fertilization and implantation occur, the ____ continues to secrete progesterone and estrogen, preventing menstruation.
Corpus luteum
In females, the development of secondary sexual characteristics at puberty is stimulated by…
Estrogen
After ovulation, the egg cell is swept into the oviduct via ____ in the tubule walls.
Waves of cilia motion
If sperm are present, they will travel upward through the uterus and meet the secondary oocyte in the…
Oviduct
Sperm the contact the egg release ____ to erode away the egg’s protective coating.
Acrosomal enzymes
If a sperm penetrates the membrane surrounding the egg cell, the…
Meiosis is completed and fertilization occurs
After fertilization, the zygote begins a series of mitotic divisions called…
Cleavage
When the embryo reaches the uterus, it is a hollow ball of cells called a…
Blastocyst
The blastocyst will implant itself in the ____ and continue development.
Endometrium
