bio chapter 35 questions

The ovaries of a newborn human female each contain about

1 million oocytes.

The fetus will first be able to first move its arms and legs in the

3rd month.

By about the ______ week, the embryo has primitive eyes, nose, and ears, as well as a primitive digestive tube.

4th

The cartilage skeleton forms in the embryo during weeks

7 and 8.

On average out of 100 sexually active, fertile women, how many will become pregnant each year if no birth control is used?

85

Select all of the correct statements about oogenesis and spermatogenesis.

Egg maturation is cyclical and only occurs during a woman's reproductive years. The production of an egg cell begins before birth and is only complete if fertilization occurs. Spermatogenesis begins at puberty and continues throughout life. It takes about 74 days to produce a sperm cell.

True or false: In both spermatogenesis and oogenesis, the cytoplasm of the diploid cell is divided equally among all daughter cells.

False

When the hypothalamus secretes ______, the anterior pituitary gland secretes ______ that stimulate the ovaries in females.

GnRH; FSH and LH

are organs that contain germ cells, which give rise to gametes.

Gonads

fertilization occurs when sperm are inserted into the body of the female.

Internal

Select all of the following that describe a fetus at three months.

Its sex is detectable. Organ systems begin to function. Nerves and muscles coordinate its actions. Bone begins to replace cartilage. Baby teeth begin to form.

feedback induces hormonal changes to cause childbirth to initiate and continue.

Positive

What gene is activated only in male embryos and is responsible for development as a male?

SRY

True or false: Plants can have sexually transmitted infections.

True

True or false: Viruses can cause birth defects.

True

At the peak of sexual stimulation, a pleasurable sensation called ______ accompanies rhythmic contractions that eject semen from the penis.

orgasm

The ______ cycle controls the maturation of the oocyte in the ovaries.

ovarian

In female animals, egg cells develop in organs called the ______, which are the gonads.

ovaries

The release of a secondary oocyte from its follicle is called

ovulation.

In a positive feedback cycle, the hormone ______ stimulates contraction of uterine muscles during childbirth.

oxytocin

By about 10 weeks after fertilization, the ______ has completely developed and consists of pools of the mother's blood surrounding the chorionic villi containing fetal blood vessels.

placenta

What term describes the headaches, cramping, depression, and many other discomforts that women experience due to fluctuating hormones?

premenstrual syndrome

The amnion helps maintain a regulated temperature and ______ that protects the developing embryo.

pressure

An intrauterine device (IUD) acts as birth control by ______, while condoms act to ______.

preventing embryo implantation; block the meeting of sperm and oocyte

At about 3 weeks, the ______ forms along the back of the embryonic disc and becomes a longitudinal axis around which structures organize as they develop.

primitive streak

Spermatogenesis is the

production of sperm

Select all of the effects of estrogen and progesterone on the second half of the female menstrual cycle.

promote thickening of endometrium inhibit release of GnRH

Select all of the contents of semen.

prostaglandins sperm cells fructose

What is the role of homeotic genes during development?

regulate the correct placement of animal body parts

After meiosis I in oogenesis, a haploid polar body and a haploid cell called a(n) ______ have formed.

secondary oocyte

During ovulation, a ______ is released from its follicle and is swept into the ______.

secondary oocyte; uterine tube

What secretes most of the fluid in semen?

seminal vesicles

In the testes, the ______ tubules produce sperm.

seminiferous

Select all of the following that are produced by the ovaries.

sex hormones egg cells

in _____ reproduction, two parents each contribute half of the DNA present in the offspring.

sexual

What is produced by the 200 tightly-coiled seminiferous tubules in the testes?

sperm

Select all of the following that are gametes.

sperm cells egg cells

Select all of the cells that are haploid.

spermatids mature sperm (spermatozoa) secondary spermatocytes

The production of sperm is a process known as

spermatogenesis.

Spermatids develop flagella and complete their differentiation into mature sperm cells called ______ in the lumen of the seminiferous tubule.

spermatozoa

Select all of the following effects of testosterone in adult males.

sustain the libido stimulate sperm production control activity of the prostate gland

The male gonads are called

testes

Select all of the following that are gonads.

testes ovaries

In male adolescents, the development of secondary sex characteristics is stimulated by

testosterone.

The blastocysts's outer layer, called the ______, will eventually combine with endometrial tissues of the uterus to form the fetal portion of the placenta.

trophoblast

The hormone hCG secreted by the ______ keeps the corpus luteum producing progesterone, which prevents menstruation.

trophoblast of the blastocyst

The ______ carries fetal blood to and from the placenta for nutrient and gas exchange.

umbilical cord

What tube extends from the ejaculatory duct through the penis and carries semen out of the body?

urethra

After ovulation, beating cilia sweep the mature oocyte into the ______, where fertilization occurs if sperm are present.

uterine tube

In the human female reproductive system, the ______ is a muscular organ in which the fetus develops.

uterus

The tube that receives the penis during intercourse and is also the birth canal is called the

vagina.

What duct carries sperm from the epididymis to the ejaculatory duct?

vas deferens

Arteries and ______ are found in the umbilical cord.

veins

An extraembryonic membrane called the _____ sac generates blood cells for the embryo for the first 6 weeks.

yolk

Select the four membranes that protect and nourish the developing embryo.

yolk sac allantois amnion chorion

Select all of the following that take place during the embryonic stage of human development.

Different organs of the embryo form. Membranes that support and protect the embryo develop.

Having three copies of chromosome 21 is a chromosomal abnormality that causes ______ syndrome.

Down

The ______ is an extraembryonic membrane that generates blood cells and vessels in the umbilical cord.

allantois

The ______ is the clear membrane that holds the amniotic fluid.

amnion

The extraembryonic membrane called the ______ contains fluid that cushions the embryo and maintains a constant temperature.

amnion

Presence of the SRY gene is responsible for the embryo developing

as a male.

In ______ reproduction, the genetic information in the offspring comes from one parent.

asexual

Select all of the following that can cause sexually transmitted infections.

bacteria viruses protists fungi

In human females, meiosis that produces egg cells first begins ______ and then pauses.

before birth

About 7 days after fertilization, the ______ has formed and consists of an inner cell mass and fluid surrounded by a layer called the trophoblast.

blastocyst

About one week into the preembryonic stage, the morula has hollowed out to form the ______ and has reached the uterus.

blastocyst

During implantation, the ______ embeds in the uterine lining.

blastocyst

What part of the human female contains milk ducts and produces milk to nourish her newborn infant?

breast

After fertilization, the zygote undergoes rapid cell division called ______ to form smaller and smaller cells that comprise the morula.

cleavage

Select all the structures that make up the vulva.

clitoris labia vaginal opening

What birth control method also protects against sexually transmitted infections?

condom

What is true about a human secondary oocyte?

contains 23 chromosomes

After ovulation in animals, the ruptured follicle differentiates into a gland called the

corpus luteum.

Tay-Sachs disease, phenylketonuria, and Rett syndrome are caused by

defective genes.

In animal development, the process by which cells and organs acquire their specialized functions due to the actions of unique combinations of genes is called

differentiation.

In ______ development, an offspring at birth resembles a smaller version of its parents.

direct

The discharge of sperm from the penis is called

ejaculation.

The embryonic disc will differentiate into the

embryo.

During the ______ stage, the organs of the embryo begin to develop.

embryonic

The ______ stage of development includes a "critical period" for almost all human body systems.

embryonic

After implantation, the inner cell mass flattens and becomes the

embryonic disc.

An embryonic layer called the ______ forms the inner layer of the gastrula.

endoderm

The lining of the uterus is called the ______ and has a rich supply of blood.

endometrium

In many species, attracting mates for sexual reproduction

entails high energy costs.

In egg formation, meiosis is not completed until ______ occurs.

fertilization

In sexual reproduction, a process called ______ is the union of two gametes.

fertilization

When ______ occurs, the secondary oocyte is triggered to complete meiosis II.

fertilization

The ______ stage is the third stage of prenatal development and lasts from 9 weeks to 38 weeks.

fetal

The organ systems have formed, are functioning, and begin coordinating during the ______ stage.

fetal

During the end of the eighth week of development, all organ systems are formed and the embryo is now called a(n)

fetus.

For fertilization to occur, the sperm must pass through ______ cells that surround the ovum.

follicle

Nourishing ______ cells surround every oocyte until ovulation occurs.

follicle

Sexual reproduction is the production of offspring

from two parents.

In fertilization, two haploid cells called ______ unit to form a diploid zygote.

gametes

The two-week-old preembryo that forms when the embryonic disc develops three layers is called the

gastrula.

Select all of the following that can cause birth defects.

genetics vitamin deficiencies viruses toxins or chemicals

In males, testosterone causes the secretion of ______ during puberty.

growth hormone

Both spermatogenesis and oogenesis result in the production of

haploid gametes.

Gametes produced in meiosis for sexual reproduction are

haploid.

Select all of the symptoms that are associated with premenstrual syndrome in women.

headaches depression cramping breast tenderness

Select all the types of signals that can stimulate cell development and differentiation during animal development.

hormones protein gradients homeotic genes

What hormone is released by the blastocyst to prevent menstruation and ovulation?

human chorionic gonadotropin (hCG)

Assuming mutations do not occur, all offspring generated from asexual reproduction are

identical to the parent and to each other.

In a process called ______, the trophoblast sends out projections and secretes enzymes to embed the blastocyst into the uterine lining.

implantation

The embryonic stage of human development occurs from

implantation to 8 weeks.

What is the main benefit of sexual reproduction for animals?

increases genetic diversity

What part of the blastocyst will develop into the embryo itself?

inner cell mass

Parts of the yolk sac will become the ______ and germ cells.

intestines

Select all of the following that are exchanged between the fetal blood vessels and the mother's blood at the placenta.

ions and amino acids oxygen and carbon dioxide glucose urea and other wastes

The clitoris is found at the upper convergence of both pairs of

labia.

At the beginning of the ovarian cycle, the levels of estrogen and progesterone are ______, and the hypothalamus stimulates the anterior pituitary gland to release ______.

low; FSH and LH

Oogenesis is the

making of an egg cell.

The ______ cycle prepares the uterus for pregnancy.

menstrual

The middle layer of the gastrula is known as the

mesoderm

In animals that undergo indirect development, the larva matures into the adult form during a process called

metamorphosis.

In oogenesis, the secondary oocyte begins meiosis II and then halts in ______, only to resume when the egg contacts sperm.

metaphase II

A solid ball of cells that forms about 3 days after fertilization is called the

morula.

High levels of estrogen exert ______ on the secretion of hormones from the hypothalamus and anterior pituitary.

negative feedback

What human body system has the longest critical period and is often affected in many birth defect syndromes?

nervous system

Select all of the following that are true about the human embryo around 4 weeks.

neural crest cells migrate and form the foundation of the peripheral nervous system embryo is about 6 millimeters long limb buds appear

Select all the animals that commonly use internal fertilization.

nonavian reptiles mammals birds

Follicle cells are responsible for providing nourishment to ______ cells.

oocyte

The ovarian cycle is responsible for the timing of ______ maturation in the ovaries.

oocyte

During oogenesis, division of an oogonium forms two primary

oocytes.

The production of egg cells is called

oogenesis

______ cells are manufactured by the allantois and the yolk sac.

Blood

The location of the testes outside the body within the scrotum allows

a slightly cooler temperature for sperm to develop.

Select all of the following that are secondary sex characteristics of human females.

accumulation of fat around the hips wider hips development of breasts that contain ducts and fatty tissue

What structure of the sperm cell contains enzymes that are released to help the sperm penetrate the outer layers of the egg during fertilization?

acrosome