Chapter 42: Animal Reproduction and Development

define an organelle that surrounds the head of the sperm containing enzymes that enable sperm to transverse the outer coating of the egg

acrosome

define a membrane that encloses a space where metabolic wastes collect

allantois

A watertight sac, called the ___________, is an adaptation for reproduction on land.

amnion

define a membrane surrounding a fluid-filled cavity that allows the embryo to develop in a watery environment

amnion

define the reproduction of cells or single-celled organisms by cell division; offspring are clones of the parent.

asexual reproduction

Gastrulation results in the formation of the three germ layers—___________, ____________, and _____________

ectoderm, mesoderm, and endoderm

define the duct through which sperm travel from the vas deferens to the urethra

ejaculatory duct

define an early stage of multicellular development that results from successive mitotic divisions of the zygote.

embryo

Many organisms reproduce both sexually and asexually. For some organisms, ___________________ conditions favor one mode or the other.

environmental

In general, sexual reproduction is more likely found in species that live in:

environments with variable conditions than in species that live in environments with constant conditions

define an organ that lies above the testes where sperm become motile and are stored prior to ejaculation

epididymis

define a hormone secreted by the ovaries that stimulates the development of female secondary sexual characteristics.

estrogen

define a cycle in placental mammals other than humans and chimpanzees characterized by phases in which females are sexually receptive

estrus cycle

define fertilization that takes place outside the body of the female; in aquatic organisms, for example, eggs and sperm are released into the water.

external fertilization

define one of several sheets of cells that extend out from the developing embryo and form the yolk sac, amnion, allantois, and chorion

extraembryonic membrane

An oocyte is released from the ovary, travels through the ______________, and implants in the uterus if it is fertilized.

fallopian tube

define a tube from each ovary, through one of which a released oocyte passes

fallopian tube (oviduct)

define the union of gametes to produce a diploid zygote

fertilization

define the embryo toward the end of the first trimester (in humans)

fetus

define fertilization that takes place inside the body of the female.

internal fertilization

Among vertebrates, external fertilization: (Select all that apply.)

involves releasing gametes directly into a wet environment; is found in some fish and amphibians

Budding: (Select all that apply.)

is found in fungi, plants, and some animals; is a form of asexual reproduction; involves an unequal division between a mother and daughter cell or organism

One of the advantages of sexual reproduction is the production of novel arrangements of genes on chromosomes due to recombination during meiosis. This effect is further magnified upon fertilization because offspring:

may have allele combinations of genes that are not seen in either parent.

define a form of cell division that includes only one round of DNA replication but two rounds of nuclear division

meiotic cell division

define the cessation of menstrual cycles resulting from decreased production of estradiol and progesterone by the ovaries

menopause

define a monthly cycle in females in which oocytes mature and are released from the ovary under the influence of hormones

menstrual cycle

define the monthly shedding of the uterine lining

menstruation

In females, ____________________ are driven by the interplay of hypothalamic, anterior pituitary, and ovarian hormones, leading to ___________, which is the maturation and release of an oocyte from the ovary, and to changes to the uterine lining

monthly menstrual cycles; ovulation

define the solid ball of cells resulting from early cell divisions of the fertilized egg

morula

define the unfertilized egg cell produced by the mother; the developing female gamete

oocyte

Developing female gametes, called __________, are produced in the ovaries. Mature ones are called eggs, or ova.

oocytes

define the formation of ova or eggs.

oogenesis

define giving birth to live young, with nutritional support of the embryo from the mother.

viviparity

define the external genitalia of the female

vulva (labia majora((outer)) and labia minora((inner)) )

define the diploid cell formed by the fusion of two gametes

zygote

___________ is the division of the zygote by mitotic cell division into smaller cells. At the _____________ stage, the developing embryo implants in the uterus

Cleavage; blastocyst

define glands below the prostate gland that produce a clear fluid that lubricates the urethra for passage of the sperm

bulbourethral glands

define a series of physiological changes that allow the sperm to fertilize the egg

capacitation

define the end, or neck, of the uterus

cervix

define a membrane that surrounds the entire embryo along with its yolk and allantoic sac

chorion

The ectoderm of a human embryo goes on to form all of the following EXCEPT the:

circulatory system

define the successive mitotic divisions of the zygote after fertilization, in which the single large egg is divided into many smaller cells

cleavage

define the female homolog of the glans penis.

clitoris

define an individual that carries an exact copy of the nuclear genome of another individual; they are genetically identical cells or individuals

clone

______________, mediated by the posterior pituitary hormone _____________, involves changes in the cervix, delivery of the baby, and delivery of the placenta.

Childbirth; oxytocin

define a sac outside the abdominal cavity of the male that holds the testes

scrotum

define a trait that characterizes and differentiates the two sexes but that does not relate directly to reproduction.

secondary sexual characteristic

define a fluid that nourishes and sustains sperm as they travel in the male and then the female reproductive tracts

semen

define two glands at the junction of the vas deferens and the prostate gland that secrete a protein- and sugar-rich fluid that makes up most of the semen and provides energy for sperm motility

seminal vesicles

define a series of tubes in the testes where sperm are produced

seminiferous tubules

define the factors that trigger development of male or female characteristics (in humans it occurs bc of the Y chromosome)

sex determination

define the process of producing offspring that receive genetic material from two parents; in eukaryotes, the process occurs through meiosis and fertilization.

sexual reproduction

Male gametes, called ___________, develop in the seminiferous tubules of the testes

sperm

Gametogenesis is called __________________ in males and _____________ in females.

spermatogenesis; oogenesis

In males, spermatogonia differentiate into primary spermatocytes that undergo meiosis to make immature haploid spermatogenesis _____________ and mature spermatozoa or ________

spermatogenesis; sperm

define the smaller, male gametes

spermatozoa (sperm)

define a steroid hormone, secreted by the testes, that plays key roles in male growth, development, and reproduction

testosterone

define the three periods of pregnancy, each lasting about 3 months

trimesters

T or F: The developing fetus is most vulnerable to toxins, drugs, and infections during the first trimester of pregnancy because all of the basic structures and organ systems develop during this time

true

define a tube from the bladder that in males carries semen as well as urine from the body

urethra

Some women choose to have their fallopian tubes "tied" in order to prevent future pregnancies after the procedure. How does this procedure prevent pregnancy from occurring?

Eggs are prevented from passing through the fallopian tubes to be fertilized by sperm

Which of the following would you expect if a tumor growing in the seminal vesicles rendered it nonfunctional?

Ejaculate would have lower volume.

___________________ involves the production of haploid gametes by meiotic cell division and the fusion of gametes to make a diploid zygote.

Sexual reproduction

_____________________ produces genetically unique offspring

Sexual reproduction

define a hollow organ within the reproductive tract of female mammals with thick, muscular walls that is adapted to support the developing embryo if fertilization occurs and to deliver the baby during birth.

uterus

define a tubular channel connecting the uterus to the exterior of the body; also known as the birth canal.

vagina

define a long, muscular tube from the scrotum, through the abdominal cavity, along the bladder, and connecting with the ejaculatory duct.

vas deferens

In females, estrogen and progesterone:

1. direct development of female secondary sexual characteristics during puberty. 2. maintain adult health. 3. direct development of female reproductive structures during embryogenesis. 4. regulate the menstrual cycle and support pregnancy.

During the follicular phase of the menstrual cycle, a number of events occur which are listed below. Select the answer that places the events in the CORRECT chronological order. Events: 1. the lining of the uterus thickens 2. granulosa cells secrete estradiol 3. FSH acts on granulosa cells 4. LH levels surge rapidly then decline 5. ovulation occurs

3, 2, 1, 4, 5

_________________ involves a single parent. Offspring are produced by binary fission or mitotic cell division and are clones of the parent.

Asexual reproduction

_______________________ allows rapid population growth but produces clones and results in genetic uniformity

Asexual reproduction

Fertilization can occur outside or inside the body of the female. _____________________ can occur only in an aquatic environment. __________________ is an adaptation to terrestrial living

External fertilization; Internal fertilization

___________ fertilization is usually associated with the production of many offspring, little or no parental care, and high mortality. These are characteristics of __________________

External; r-strategists

_______________ is the fusion of the oocyte and sperm plasma membranes. It usually occurs in the fallopian tube and results in the formation of a diploid zygote.

Fertilization

______________ fertilization is often associated with the production of fewer offspring, increased parental care, and low mortality. These are characteristics of ______________

Internal; K-strategists

define a species that produces relatively few young but invests considerable resources into their support

K-strategist

define a type of cell in the testes that secretes testosterone

Leydig cell

_______________ is the formation of organs

Organogenesis

_________________ lasts about 38 weeks from fertilization until birth and is divided into _________________

Pregnancy; three trimesters

___________ is a mixture of sperm and fluid from the prostate gland, seminal vesicles, and bulbourethral glands

Semen

define a type of cell in the seminiferous tubules that supports sperm production.

Sertoli cell

define a form of asexual reproduction in fungi, plants, and some animals in which a bud forms on the organism and eventually breaks off to form a new organism that is smaller than its parent.

budding

define a fluid-filled ball of undifferentiated cells formed after the fertilized egg has undergone several rounds of mitotic cell division following the morula stage.

blastula

Examples of asexual reproduction include _________, ____________________, and _____________________

budding; fragmentation; parthenogenesis

define an organelle that propels the movement of cells or of substances within cells; longer than a cilium

flagellum

define a type of cell that makes up the shell of cells surrounding an oocyte that supports the developing oocyte.

follicle

define a form of asexual reproduction in which new individuals arise by the splitting of one organism into pieces, each of which develops into a new individual.

fragmentation

define the formation of gametes

gametogenesis

define a highly coordinated set of cell movements in which the cells of the blastoderm migrate inward, creating germ layers of cells within the embryo.

gastrulation

define the head of the human penis

glans penis

define a process in which eggs and sperm are brought together in a petri dish, where fertilization and early cell divisions occur

in vitro fertilization (IVF

define the transformation of the three germ layers into all the organ systems of the body

organogenesis

define laying eggs

oviparity

define giving birth to live young, with nutritional support of the embryo from the yolk

ovoviviparity

define the larger, female gametes

ovum (egg)

define a form of asexual reproduction in which females produce eggs that are not fertilized by males but divide by mitosis and develop into new individuals.

parthenogenesis

define the male copulatory organ

penis

define an organ formed by the fusion of the chorion and allantois that allows the embryo to obtain nutrients directly from the mother.

placenta

define fertilization by more than one sperm

polyspermy

define the carrying of one or more embryos in the mammalian uterus

pregnancy

define a hormone secreted by the vertebrate ovaries that maintains the thickened and vascularized uterine lining

progesterone

define an exocrine gland that produces a thin, slightly alkaline fluid that helps maintain sperm motility and counteracts the acidity of the female reproductive tract.

prostate gland

Spermatogenesis begins at ______________ and continues throughout life

puberty

define a species that produces large numbers of offspring but provides few resources for their support

r-strategist