Reproduction Flashcards
process of producing offspring that are biologically or genetically similar to the parent organism
reproduction
Two (2) modes of reproduction
- Asexual reproduction
- Sexual reproduction
- a single parent produces offspring
- all offspring are genetic replicas of the parent and identical to one another
asexual reproduction
Types of Asexual Reproduction
- Binary fission
- Budding
- Fragmentation
- Regeneration
- Parthenogenesis
- occurs in single-celled organisms
- parent cell divides itself into two
binary fission
offspring grows out of the body of the parent
budding
offspring grows from a broken piece of body of an organism
fragmentation
- modified form of fragmentation
- when a body part of an organism detaches from the parent body, it grows into a completely new individual
regeneration
egg develops without fertilization
parthenogenesis
example of organisms that undergo binary fission
bacteria
example of organisms that undergo budding
hydra
example of organisms that undergo fragmentation
coral
example of organisms that undergo regeneration
planarian
example of organisms that undergo parthenogenesis
- bees
- wasps
- ants
- aphids
- two parent produce haploid gametes (egg and sperm) that combine at fertilization
- each resulting offspring has a unique combination of paternal and maternal genes
sexual reproduction
produce both eggs and sperm
hermaphrodites
the same organism has both the male and female sex organs and produces both types of gametes
Simultaneous hermaphrodite
an organism switches from its inborn sex to the opposite sex
Sequential hermaphroditism
example of simultaneous hermaphrodite
- tapeworms
- some roundworms
example of sequential hermaphrodite
- teleost fishes
- oyster
Mechanisms of Fertilization
- Internal Fertilization
- External Fertilization
the fusion of gametes happen inside the female body
internal fertilization
Ways offspring are produced by internal fertilization
- Oviparity
- Viviparity
- Ovoviviparity
the female has fertilized eggs laid outside its body
oviparity
the offspring develops within the female and is nourished by the mother’s blood in the placenta
viviparity
fertilized eggs nourish the young from its yolk; lay the eggs when they are ready to hatch
ovoviviparity
example of animals that are oviparous
- frogs
- lizards
- birds
- fishes
example of animals that are viviparous
mammals
example of animals that are ovoviviparous
- flies
- sharks
- rays
the fusion of gametes happen outside the female body
external fertilization
Advantages of Asexual Reproduction
- no need for mate
- less time and energy
- reliable
- produces large number of offspring very quickly
- require less parental care
Disadvantages of Asexual Reproduction
- very little genetic variation in population
- harmful mutation in parent will be passed on to all offspring
- entire population of genetically-identical organisms can go extinct if there is change in environment
Advantages of Sexual Reproduction
- each offspring is unique
- more genetic variation
- population able to adapt changes in environment
- increased diversity
Disadvantages of Sexual Reproduction
- time and energy to find mate
- fewer offspring
- more time to develop offspring
- tends to require more parental care
Factors that affects the success of reproduction
- Predation
- Environment
- Human Interaction
Male Reproductive Anatomy
- Produces sperm cells
- Regulated by hormones
- Varies from species to species
The bag of skin that holds and helps to protect the testicles.
Scrotum
- One of two egg-shaped glands inside the scrotum that produce sperm and male hormones
- Also called testicle
testis
- A narrow, tightly-coiled tube that is attached to each of the testicles
- sperm cells move from the testicles into it, where they finish maturing and are stored.
epididymis
A coiled tube that carries the sperm out of the testes
vas deferens
the site of spermatogenesis where germ cells develop into spermatozoa in close interaction with Sertoli cells
seminiferous tubules
cells closest to the surface are ___
immature
cells closest to the lumen are ___ ___
candidate sperms
Sperm head
- contain DNA
- tip of the sperm head = acrosome
- midpiece contains the mitochondria which supplies energy tail needs to move
contains enzymes that break down the outer membrane of an egg cell, allowing the sperm to fertilize the egg
acrosome
- production of mature spermatozoa from spermatids
- a spermatozoon is produced from a spermatid
Spermiogenesis
- formation of motile spermatozoa from spermatogonium
- four functional spermatozoa are produced from a spermatogonium
Spermatogenesis
sperm + other materials = ___
semen
paired ductal structures which secrete fluid that will form part of the semen
seminal vesicles
mix the sperm stored in the ampulla with fluids secreted by the seminal vesicles and to transport these substances to the prostate
ejaculatory duct
produce the fluid that nourishes and transports sperm (seminal fluid)
prostate gland
- Fluid from the prostate and other sex glands that helps transport sperm out of the man’s body during orgasm
- contains sugar as an energy source for sperm
Seminal fluid
produce thick clear mucus prior to ejaculation that drains into the spongy urethra
Cowper’s gland
Cowper’s glands are also known as ___ ___
bulbourethral glands
What does the Cowper’s gland secrete
alkaline mucus-like fluid
attached to the pubic symphysis, which holds the penis close to the pubic bone and supports it when erect
suspensory ligament
hold and stabilize the prostate against the pubic bone
Puboprostatic ligaments
traversed by the urethra (membranous portion) and the ducts of the bulbourethral glands, along with several accompanying vessels and nerves
perineal membrane
located at the same level as the membranous urethra and is composed of circular muscle fibers
external urethral sphincter
the male sexual organ
penis
forms most of the penis and contains blood vessels that fill with blood to help make an erection
corpus cavernosum
- refers to the head of the penis
- supplied with nerve endings and is partly or wholly sheathed
glans penis
outer layer of skin that covers the head of the penis
foreskin
Opening where urine and sperm (in males) leaves the body
urethral opening
Female Reproductive Anatomy
- produces egg cells (oogenesis)
- ovarian and uterine cycle (menstrual cycle)
- regulated by hormones
growth process in which the primary egg cell (or ovum) becomes a mature ovum
oogenesis
medical term used when there are no sperm in the ejaculate
Azoospermia
thick, white, cheesy substance that collects under the foreskin of the penis
Smegma
medication used to treat erectile dysfunction and pulmonary arterial hypertension
Sildenafil
One of a pair of female glands in which the eggs form and the female hormones estrogen and progesterone are made
ovary
female reproductive hormones
- estrogen
- progesterone
group of hormones that play an important role in the normal sexual and reproductive development in women
Estrogens
- hormone that occurs naturally in the body
- involved in pregnancy and is produced mainly in the ovaries
Progesterone
either of a pair of tubes along which eggs travel from the ovaries to the uterus
Uterine/ Fallopian Tube
hollow muscular organ located in the female pelvis between the bladder and rectum
uterus
The layer of tissue that lines the uterus
endometrium
- passes through the cervix
- allows blood from a menstrual period and a baby (fetus) to pass from the womb into the vagina
cervical canal
occurs when a fertilized egg implants and grows outside the main cavity of the uterus
ectopic pregnancy
The lower, narrow end of the uterus that forms a canal between the uterus and vagina
cervix
elastic, muscular canal with a soft, flexible lining that provides lubrication and sensation
vagina
Ovary of chickens
- stalk of ovary
- empty follicle
- funnel-shaped and lies adjacent to the ovary
- has the function of searching for and engulfing the yolk that has just been released from the follicle into the adjacent ovarian pocket or body cavity
- 9 cm
Infundibulum
- longest segment at up to 40 centimetres long
- function is to add approximately 40% of the albumen to the developing egg that takes about three hours to move through
magnum
where the inner and outer shell membranes form
isthmus
serve as the mating organs of chicken
papillae (plural of papilla)
where feces and eggs exit her body and sperm enter
cloaca
the fold of skin surrounding the clitoris
prepuce
- sensitive area located on the top of your vulva
- touching the area can make you feel sexually aroused and lead to climax, or an orgasm
clitoris
(outer lips) are usually fleshy and covered with pubic hair
labia majora
The external opening of the transport tube that leads from the bladder to discharge urine outside the body in a female
urethral orifice
(inner lips) two inner skin folds that surround the opening of the vagina
labia minora
opening to the vagina itself
vaginal orifice
begins at the front of the vulva and extends to the anus
perineal raphe
hormone stimulates the corpus luteum to produce progesterone to maintain the pregnancy
Human chorionic gonadotropin (HCG)
Human chorionic gonadotropin (hCG) is a hormone produced by the ___ during pregnancy
placenta