Biology Reproductive System

Question 1

___ differs asexual reproduction in that the genetic material of two organisms combines and results in a genetically unique offspring

Answer 1

sexual reproduction

Question 2

Sexual reproduction occurs via the fusion of two ___, the specialized cells produced by each parent

Answer 2

gametes

Question 3

Sexual reproduction requires:
production of ___ sex cells or gametes by adult organisms
union of these cells (fertilization or conjugation) to form a zygote
development of the zygote into another adult, completing the cycle

Answer 3

functional

Question 4

___, the production of gametes, occurs in specialized organs called gonads

Answer 4

gametogenesis

Question 5

The male gonads, the testes, produce sperm in the tightly coiled ___ tubules

Answer 5

seminiferous

Question 6

The female gonads, the ___, produce oocytes (eggs)

Answer 6

ovaries

Question 7

Some species are ___, which possess both functional male and female gonads

Answer 7

hermaphrodites

Question 8

___, or sperm production, occurs in the seminiferous tubules of the testes

Answer 8

spermatogenesis

Question 9

In females, the process is called ___, or egg production, and occurs in the ovaries

Answer 9

oogenesis

Question 10

___ is the union of the egg and sperm nuclei to form a zygote with a diploid number of chromosomes

Answer 10

fertilization

Question 11

___ is practiced by terrestrial vertebrates and provides a direct route for sperm to reach the egg cell

Answer 11

internal fertilization

Question 12

Pathway of Sperm through the male reproductive system: SEVE(N) UP
Seminiferous tubules
Epididymis
vas deferens (also called the ductus deferens)
Ejaculatory duct
(Next)
\_\_\_
Penis

Answer 12

Urethra

Question 13

The ___ are located in the scrotum, an external pouch that maintains the testes’ temperature at 2 to 4 degrees lower than body temperature, a condition essential for sperm survival

Answer 13

testes

Question 14

The sperm cells mature in the ___, a structure resting atop of testes

Answer 14

epididymis

Question 15

FSH acts on the ___ cells, located in the seminiferous tubules, to support the development of maturing sperm cells

Answer 15

sertoli

Question 16

LH acts on ___ cells to stimulate testosterone production in the testes

Answer 16

leydig

Question 17

In the seminiferous tubules diploid cells called spermatogonia differentiate into ___ cells called primary spermatocytes, which undergo a meiotic division to yield two haploid secondary spermatocytes of equal size; a second meiotic division produces four haploid spermatids of equal size

Answer 17

diploid

Question 18

After miosis, the ___ undergo a final series of changes that increase their mobility, resulting in mature sperm, or spermatozoa

Answer 18

spermatids

Question 19

On a mature sperm, a caplike structure called the acrosome, derived from the ___, develops over the anterior half of the head

Answer 19

Golgi apparatus

Question 20

The ___ contains enzymes needed to penetrate the tough outer covering of the ovum

Answer 20

acrosome

Question 21

In a female, it is the follicle cells that produce ___

Answer 21

estrogen

Question 22

Approximately once a month, an immature ovum is released (ovulation) from the ___ into the abdominal cavity and drawn by cilia into the nearby oviduct, also known as a fallopian tube

Answer 22

ovary

Question 23

Each fallopian tube opens into the upper end of a muscular chamber called the ___, the site of fetal development

Answer 23

uterus

Question 24

The lower, narrow end of the uterus is called the ___

Answer 24

cervix

Question 25

The cervix connects with the vaginal canal, which is the site of sperm deposition during ___ and is also the passageway through which a baby is expelled during childbirth

Answer 25

intercourse

Question 26

Oogenesis, the production of female gametes, occurs in the ovarian ___

Answer 26

follicles

Question 27

At birth, most of the immature ___, known as primary oocytes, that a female will produce during her lifetime have already formed

Answer 27

ova

Question 28

Primary oocytes are diploid cells that form by mitosis in the ___

Answer 28

ovary

Question 29

After menarche (the first time a female menstruates), one primary oocyte per month completes meiosis I, yielding two daughter cells of unequal size - a secondary ___ and a small cell known as a polar body

Answer 29

oocyte

Question 30

The secondary oocyte is expelled from the ___ during ovulation, while the polar body gets reabsorbed

Answer 30

follicle

Question 31

___ (oogenesis) does not occur until fertilization

Answer 31

Meiosis II

Question 32

The ___ cell membrane is surrounded by two layers of cells; the inner zona pellucida layer and the outer corona radiata layer

Answer 32

oocyte

Question 33

Meiosis II occurs when the zona pellucida and corona radiata layers are penetrated by a sperm cell, yielding two haploid cells - a mature ___ and another polar body

Answer 33

ovum

Question 34

The ovaries synthesize and secrete female sex hormones, including estrogens and ___

Answer 34

progesterone

Question 35

The secretion of both estrogens and and progesterone is ___ by luteinizing hormone (LH) and follicle stimulating hormone (FSH), which, are regulated by gonadotropin-releasing hormone (GnRH)

Answer 35

regulated

Question 36

___ are secreted by the ovarian follicles and the corpus luteum

Answer 36

Estrogens

Question 37

Progesterone stimulates the development and maintenance of the ___ in preparation for implantation

Answer 37

endometrium

Question 38

The follicular phase focuses on the growth of the follicle, specifically the growth of the ___

Answer 38

follicle

Question 39

The ___ phase begins with the cessation of menses (menstruation) from the previous cycle, which results in a decrease in progesterone

Answer 39

follicular

Question 40

Throughout the follicular phase, blood ___ levels increase, eventually triggering the next phase, ovulation

Answer 40

estrogen

Question 41

Midway through the cycle, ovulation occurs - a mature ___ follicle bursts and releases an ovum into the fallopian tube

Answer 41

ovarian

Question 42

___ is caused by a surge in LH that is preceded, and caused by, a peak in estrogen levels

Answer 42

ovulation

Question 43

As ___levels increase during the follicular phase, a concentration threshold is reached that causes a positive feedback loop with the anterior pituitary, inducing the LH surge (a smaller FSH surge also occurs)

Answer 43

estrogen

Question 44

A surge in estrogen during ovulation causes the mature follicle to burst, releasing the ovum while the follicle exterior transforms into the corpus luteum (___body)

Answer 44

luteal

Question 45

After ___, LH levels are relatively high but begin to drop due to hormone interaction with the corpus luteum

Answer 45

ovulation

Question 46

LH maintains the corpus luteum, which secretes estrogen and ___

Answer 46

progesterone

Question 47

When there is an increase in estrogen and progesterone, a negative ___ loop occurs, thereby decreasing LH levels therefore the corpus luteum is on a biological timer, as it secretes more progesterone the less LH is present which causes the degradation of the corpus luteum, triggering menstruation

Answer 47

feedback

Question 48

During the luteal phase, ___ causes the glands of the endometrium to mature and produce secretions that prepare it for the implantation of an embryo

Answer 48

progesterone

Question 49

During menstruation, if the ovum is not fertilized, the ___ atrophies due to a decrease in LH

Answer 49

corpus luteum

Question 50

When the corpus luteum atrophies, the resulting drop in ___ and estrogen levels causes the endometrium (with its superficial blood vessels) to shed, giving rise to the menstrual flow (menses)

Answer 50

progesterone

Question 51

If fertilization occurs, menstruation is avoided as both the resulting ___ and the developing placenta produce hCG (human chorionic gonadotropin)

Answer 51

zygote

Question 52

Human chorionic gonadotropin is a LH analog which maintains the corpus luteum, therefore ensuring a continuous supply of estrogen and ___ needed to maintain the uterus

Answer 52

progesterone

Question 53

An ___ can be fertilized during the 12-24 hours after ovulation

Answer 53

egg

Question 54

___ most often occurs in the lateral, widest portion of the fallopian tube

Answer 54

fertilization

Question 55

Enzymes secreted by the ___ aid in penetration of the corona radiata

Answer 55

sperm

Question 56

The acrosome is responsible for penetrating the ___; it releases enzymes that digest this layer, thereby allowing the sperm to come into direct contact with the ovum cell membrane

Answer 56

zona pellucida

Question 57

Once in contact with the ovum cell membrane, the sperm forms a tubelike structure called the ___ process, which extends to the cell membrane and penetrates it, fusing the sperm cell membrane with that of the ovum

Answer 57

acrosomal

Question 58

Once the sperm cell membrane fuses with that of the ovum the sperm ___ now enters the ovum's cytoplasm

Answer 58

nucleus

Question 59

Once the ___ nucleus enters the ovum the ovum completes meiosis II

Answer 59

sperm

Question 60

The acrosomal reaction triggers a cortical reaction in the ovum, causing calcium ions to be released into the cytoplasm; this initiates a series of reactions that result in the formation of the ___ membrane

Answer 60

fertilization

Question 61

The ___ is a hard layer that surrounds the ovum cell membrane and prevents multiple fertilizations

Answer 61

fertilization membrane

Question 62

The release of Ca2+ in the ___ of the ovum also stimulates metabolic changes within the ovum, greatly increasing its metabolic rate

Answer 62

cytoplasm

Question 63

When the metabolic rate of the ovum (having had Ca2+ released in the ___ already) increases, this is followed by the fusion of the sperm nucleus with the ovum nucleus to form a diploid zygote

Answer 63

cytoplasm

Question 64

When the fusion of the sperm nucleus with the ovum nucleus occurs to form a diploid ___, the first mitotic division of the zygote soon follows

Answer 64

zygote