Male Reproductive System
Each human cell normally contains ______ pair/pairs of sex chromosomes
1
In mitosis each parent cell produces ______ daughter cells, while in meiosis, ______ gametes are produced
2, 4
Most human cells contain ______ pairs of chromosomes
23
About ______ of boys are born with cryptorchidism
3%
During meiosis II, each secondary spermatocyte divides, resulting in a total of spermatids combined from the two spermatocytes
4
A healthy, post-pubescent, young man can produce about how many sperm per day?
400 million
What is a hormone secreted by the testes that causes atrophy of the paramesonephric duct?
MIF
The Y chromosome has a gene called _____ , which initiates the development of male reproductive structures
SRY
Which gene on the Y chromosome leads to the development of a male reproductive anatomy?
SRY
True or false: A four week old fetus has the potential to produce both male or female gonads
True
Which are sex chromosomes?
X Chromosomes Y Chromosomes
Which sex chromosome is responsible for classifying an individual as male?
Y chromosome
The modified lysosome within a spermatozoon that contains enzymes needed to penetrate the egg is called the _____
acrosome
Which part of a sperm is a modified lysosome and contains enzymes needed to penetrate the egg?
acrosome
In humans, when do the secondary sexual characteristics first appear?
at puberty
Any chromosome other than a sex chromosome is known as a(n) ______
autosome
Biparental inheritance is achieved when offspring receive genes from which of the following?
both the egg and sperm
Each individual has genes inherited from which of the following?
both the male and female parents
The penis is homologous to the ______ of the female
clitoris
During prophase I homologous chromosomes exchange segments of DNA in a process called _____ over
crossing
Human somatic (body) cells are ______; they have ______ chromosomes
diploid, 46
In the male, which are considered secondary sex organs?
ducts that convey sperm penis glands that contribute to semen
What are the two requirements for sperm motility?
energy source elevated pH
True or false: Sperm motility is dependent upon a low pH and an energy source
false
If an egg is fertilized with an X-bearing sperm, it produces an XX zygote that is destined to become a ______
female
The paramesonephric ducts will develop into the ______ reproductive tract
female
What does meiosis produce?
four genetically unique daughter cells
Which are secreted by the seminal vesicles?
fructose proseminogelin prostaglandins
The sex cells, sperm and eggs, are referred to as which of the following?
gametes
Homologous chromosomes exchange segments of DNA in a process called crossing-over. This produces ______
genetically unique sister chromatids
Which are found in both a male and female 6 week embryo?
genital tubercle labioscrotal folds urogenital folds
The gubernaculum is a connective tissue cord that extends from the ______ to the ______ of a developing fetus
gonad floor of abdomopelvic cavity
The is a connective tissue cord that extends from the gonad to the floor of the abdominopelvic cavity during development
gubernaculum
While somatic cells are diploid, gametes are _____ they have one copy of each type of chromosome
haploid
Which region of the spermatozoon contains the nucleus?
head
A sperm count lower than 20 to 25 million sperm/mL usually results in a condition called ______
infertility
A sperm count lower than 20 to 25 million sperm/mL usually results in a condition called ______.
infertility
The _____ canal allows the passage of the testes through the abdominal musculature during development.
inguinal
List the events that occur during spermiogenesis
loss of excess cytoplasm growth of a flagellum
A sperm is a ______ gamete.
male
If an egg is fertilized with a Y-bearing sperm, it produces an XY zygote that is destined to become a ______
male
Genetically, a human with XY chromosomes is a ______ while one with XX chromosomes is a ______
male, female
Genetic recombination and the reduction in chromosome number by one-half, are achieved through which form of cell division?
meiosis
Human gametes are produced via what type of cell division?
meiosis
Which process produces genetically unique haploid cells?
meiosis
Up to a point, a fetus is sexually undifferentiated, as it has both ducts and paramesonephric ducts
mesonephric
The _____ of the sperm contains numerous mitochondria needed to provide energy (ATP) for locomotion.
midpiece
Where are mitochondria located in a sperm?
midpiece
Which traits are commonly regarded as male secondary sex characteristics?
muscular physique facial hair coarse and visible hair on the torso and limbs deeper voice
Where do both male and female gonads develop initially?
near the kidneys
The head of a sperm is comprised of what three components?
nucleus acrosome flagellar basal body
A mature female gamete, an egg, is also known as a(n) ______
ovum
Which describes a mature spermatozoon?
pear-shaped head with a long tail
The internal genitalia are located mainly within the ______ cavity
pelvic
Where are most of the internal genitalia located?
pelvic cavity
Match each male anatomical structure with its homologous structure in the female
penis - clitoris scrotum - labia majora testes - ovaries
Which organs produce gametes?
primary sex organs
Which cell undergoes meiosis I giving rise to two equal-size, haploid, and genetically-unique secondary spermatocytes?
primary spermatocyte
What are the earliest stem cells specifically destined to become spermatogonia?
primordial germ cells
Meiosis I of spermatogenesis gives rise to two equal-size, haploid and genetically unique spermatocytes
secondary
The uterine tubes, uterus, vagina and external genitalia are examples of which sex organs of a female?
secondary sex organs
Within the male reproductive system, a system of ducts, glands, and the penis are considered which of the following?
secondary sex organs
A typical ejaculation results in the discharge of 2 to 5mL of a fluid called ______?
semen
The fluid expelled during male orgasm is called _____?
semen
Where does spermatogenesis occur?
seminiferous tubules
Which secretion of the prostrate breaks down semenogelin, liquifying the semen?
serine protease
The male reproductive structures function to produce ______ cells and introduce them into the vagina
sperm
A spermatozoon is a mature ______.
sperm cell
Each secondary spermatocyte undergoes meiosis II, giving rise to which of the following?
spermatids
The process of sperm production is ______
spermatogenesis
Which is the term for the process of sperm production?
spermatogenesis
Which is the stem cell that directly produces spermatocytes?
spermatogonium
Which type of stem cell produces cells which, in turn, enter meiosis?
spermatogonium
A pear-shaped head and long tail are the two major parts of which of the following?
spermatozoon
What is the term for a mature sperm cell?
spermatozoon
About 3% of boys are born with undescended ______, also called cryptorchidism
testes
The descent of the ______ begins as early as week 6 of embryonic development
testes
The primary sex organs of the male are the ______
testes
Which normally pass through the inguinal canals?
testes
In the embryonic development of a male, the hormone ______ is produced by the testes and stimulates development of the male reproductive ducts
testesterone
In prophase I of meiosis, each pair of homologous chromosomes line up side by side and form a(n)
tetrad
In prophase I of meiosis, each pair of homologous chromosomes line up side by side and form what?
tetrad
What is infertility?
the inability to fertilize an egg
What does it mean if structures are homologous?
they are derived from the same embryological structure
What is the main goal of meiosis?
to produce cells with one copy of each chromosome
Which are functions of the male reproductive system?
to produce sperm to introduce sperm into the female body
True or false: A healthy, post-pubescent, young man can produce about 300,000 sperm per minute
true
True or false: Both male and female gonads initially develop near the kidneys in the fetus
true
When does descent of the testes begins?
week 6
Where do primordial germ cells destined to become sperm form?
yolk sac
A single-celled, fertilized egg is called a(n)
zygote
