Reproduction and Embryology

all non-animals reproduce by \_____

asexual reproduction

asexual reproduction means all offspring are \_____ to the parent

genetically identical

what are some common examples of asexual reproduction?

binary fission; budding; regeneration; parthenogenesis

list the steps of binary fission:

DNA replication --\> DNA migration to opposite cell poles --\> septum formation --\> septum splitting

the \_____ creates a dividing wall during binary fission

septum

where does binary fission occur?

in prokaryotes and some organelles within eukaryotes (mitochondria and chloroplasts)

budding can occur in \_____ or \_____ organisms

unicellular; multicellular

list the steps of budding:

outgrowth on original organism --\> DNA replication --\> replicated DNA deposition into the bud --\> bud/organism separation

what is an example of a eukaryotic organism that uses budding?

yeast (fungus)

in regeneration (fragmentation), a piece of an organism breaks off to create 2 organisms - each organism is half \_____ and half \_____

old; new

what are some examples of organisms that use regeneration (fragmentation)?

hydra and planaria flatworms

\_____ occurs when an unfertilized egg develops into a viable organism

parthenogenesis

organisms that display parthenogenesis (asexual) can usually perform asexual or sexual reproduction - when do they use sexual?

when environmental conditions are *not* ideal

bees are a common \_____ organism

haplodiploid

\_____ means that sex determination is based on whether the organism is haploid or diploid at that time

haplodiploid

bee offspring that arise from unfertilized eggs (parthenogenesis) are \_____ male drones

haploid

bee offspring that arise from fertilized eggs (sexual) are \_____ females

diploid

humans engage in sexual reproduction, meaning offspring are created when two \_____ join

haploid gametes

\_____ produce gametes

germ cells

(spermatogonia are male germ cells)

\_____ are the only cells that can undergo mitosis and meiosis

germ cells

(spermatogonia are male germ cells)

\_____ are male germ cells

spermatogonia

\_____ are female germ cells

oogonia

spermatogonium are replicated by \_____ in the \_____ of the testicle

mitosis; seminiferous tubules

spermatogonium are the primordial (earliest) \_____ cells

sperm

\_____ is the process of converting 1 diploid spermatocyte into 4 haploid sperms inside the \_____ of the testicles

spermatogenesis; seminiferous tubules

diploid spermatogonia differentiate into diploid \_____ to initiate spermatogenesis

primary spermatocytes

diploid, primary spermatocytes undergo the first meiotic division to produce 2 haploid cells, called

secondary spermatocytes

secondary spermatocytes (haploid) undergo the second meiotic division to produce 4 \_____

haploid spermatids

spermatids differentiate into \_____

haploid sperm

sperm are created by the differentiation of \_____

spermatids

sperm combine with various fluids to form \_____

semen

what are the 3 main parts of a sperm?

head; mid-piece; tail

which portion of the sperm contains the nucleus?

head

the head of the sperm contains an organelle called the \_____

acrosome

the \_____ contains digestive enzymes for egg cell penetration

acrosome

the \_____ of sperm contains a lot of mitochondria

mid-piece

what is the function of the mitochondria in the sperm mid-piece?

produce ATP to power flagellar motion in the sperm tail

the tail of a sperm is also a \_____

flagellum

sperm flagella are made of \_____

microtubules

microtubules are made of the protein \_____

tubulin

flagellar microtubules emanate from \_____

basal bodies

\_____ are the male reproductive gland

testis

\_____ occurs in the seminiferous tubules of the testes

spermatogenesis

spermatogenesis occurs in the \_____ of the testes

seminiferous tubules

what are the types of cells in the seminiferous tubules?

Sertoli cells; spermatogonium, primary & secondary spermatocytes; spermatids; sperm

spermatogenesis ends with \_____ (cell type)

spermatozoa

(sperm)

\_____ cells surround and nourish sperm cells that are developing through spermatogenesis in the seminiferous tubules

Sertoli

Sertoli cells are activated by \_____ (hormone)

FSH

\_____ is a peptide hormone that is secreted by the anterior pituitary, and it activates Sertoli cells

FSH

FSH is a \_____ hormone that is secreted by the \_____ pituitary, and it activates Sertoli cells

peptide; anterior

Sertoli cells secrete the \_____ hormone inhibin

peptide

\_____ acts on the anterior pituitary to inhibit the further release of FSH (a peptide hormone)

inhibin (from Sertoli cells)

inhibin (from Sertoli cells) acts on the \_____ pituitary to inhibit the further release of \_____ (a peptide hormone)

anterior; FSH

do the sperm fully mature in the seminiferous tubules?

no; they mature in the epidymis

describe the structure and location of the epididymis:

a duct that sits around the testes

the \_____ is the site of sperm storage before ejaculation (where sperm mature)

epididymis

the \_____ is a group of tubules that move sperm from the epididymis to ejaculatory ducts

vas deferens

what are the wave-like muscular contractions that are responsible for moving sperm through the male reproductive system?

peristalsis

the \_____ receives secretions from vas deferens and seminal vesicles

ejaculatory duct

ejaculatory ducts propel the sperm into the \_____, which leads to ejaculation of the sperm out of the penis as \_____

urethra; semen

\_____ is a combination of sperm and secretions from accessory glands

semen

what are 3 accessory glands that contribute secretions to sperm?

seminal vesicles; prostate gland; bulbourethral glands

seminal vesicles produce secretions containing \_____ sugars

fructose

fructose from the seminal vesicles acts to provide sperm with nutrients to produce \_____ for motility

ATP

seminal vesicles secrete viscous mucus, which cleans/lubricates the \_____

urethra

\_____ secrete prostaglandins to stimulate contraction of the urethra

seminal vesicles

seminal vesicles secrete \_____ to stimulate contraction of the urethra

prostaglandins

the \_____ makes semen more *alkaline (basic)*

prostate gland

what is the purpose of the prostate gland making the semen *alkaline (basic)*?

so sperm can survive the *acidity* of the *female* reproductive tract

bulbourethral glands are similar to seminal vesicles because they also secrete \_____

viscous mucus

(bulbourethral glands may also be called Cowper's glands)

pathway of the sperm?

SEVEn UP

Seminiferous tubules --\> Epididymis --\> Vas deferens --\> (nothing) --\> Ejaculatory duct --\> Urethra --\> Penis

what does follicle stimulating hormone (FSH) do in males?

stimulates sperm to develop in the seminiferous tubules

(FSH comes from the anterior pituitary)

what does luteinizing hormone (LH) do in males?

stimulates the Leydig cells of the testes to produce testosterone

(LH comes from the anterior pituitary)

Leydig cells are interstitial cells next to the \_____

seminiferous tubules

Leydig cells are stimulated by \_____ (peptide hormone) from the \_____ to produce testosterone

LH; anterior pituitary

Leydig cells are stimulated by LH (peptide hormone) from the anterior pituitary to produce \_____

testosterone

testosterone is a male \_____ hormone

gonadal steroid

testosterone functions in \_____ to mature the sperm

spermatogenesis

\_____ is responsible for contributing to male secondary sex characteristics

testosterone

the ovaries are responsible for the production of

ovums (eggs)

females have \_____ ovaries

2

ovums (eggs) travel through the \_____ after they are released from an ovary

oviduct (fallopian tube)

females have \_____ oviducts (fallopian tubes)

2

oviducts (fallopian tubes) connect the ovaries and the \_____

uterus

the uterus is a muscular organ ideal for \_____

embryo implantation

what are the 3 layers of the uterus?

*perimetrium* (outer layer); *myometrium* (smooth muscle, middle layer); *endometrium* (inner epithelial layer, lined by mucous membranes)

the \_____ connects the uterus and the vagina

cervix

the vagina acts as the opening between the \_____ with the \_____

uterus; external environment

where do sperm first enter a female body?

the vagina

where does parturition (giving birth) occur?

the vagina

\_____ (giving birth) occurs through the vagina

parturition

\_____ are primordial egg cells that are replicated by \_____ in the ovaries

oogonia; mitosis

oogonia differentiate to produce \_____

primary oocytes