Defining Terms: 46

• a haploid reproductive cell, such as an egg or sperm
• Significance: gametes unit during sexual reproduction to produce a diploid gamete

• the diploid cell produced by union of haploid gametes during fertilization; a fertilized egg
• Significance: diploid cell that reproduces by mitosis to create an individual

a form of internal reproduction through which no development occurs in the uterus or the parent's body; egg-laying animals; before egg is shed, it is covered with a protective covering, usually a hard or leathery coating

• internal fertilization through which development occurs in the mother's body; the offspring and mother are connected by a placenta between the mom and baby; it includes a live birth; young are nourished in the uterus by blood from the placenta; the mom's blood vessels are in close proxiimity to the baby's blood vessels
• all placental mammals, except marsupials

• internal fertilization that referrs to the type of development in which the young hatch from eggs that are retained in the mother's uterus; marsupials and some frongs (rhino frog)
• the embryos are carried i the body, either the male or female body; little to no interaction between parent body and embryo body
• The embryo grows in a self-sufficient manner, not using any resources from the parent except its use as a place of residence
• appears to be live birth because hte casing breaks open and allows release of offspring

• male and female sex organs; pair of reproductive organs whose function is to produce the gametes and reproductive organs
• female: ovaries
• male: testes

• fertilization (union of gametes) that occurs outside the body in a moist environment to allow sperm mobility and prevent the eggs from drying out
• large amount of gametes are released
• the female dispels her eggs and the male, his sperm
• the farther the male is, the more eggs the female dispels in hopes of increasing fertilization 
• some spawning may occur in species where the gametes are released at the same time
• pheromones can impact this as it acts as a male attractant
• chemical attractants are also important in that they are highly species specific and enable the sperm to find the egg

• fertilization that takes place within the body
• the male dispels his sperm into the female reproductive tract, where the egg is fertilized internally
• requires some behavioral and cooperative interactions, such as a copulatory organ to ensure some sperm gets into the body

• organs located outside the male and female body that are necessary for the union of the male and female
• Males: penis with the urethra, which dispels urine and semen at different times
• Female: vulva is the collective term for the female external genitalia (pudendum); two openings: vaginal and urethral  

a form of internal fertilization through which the organism has both male and female reproductive organs; there is no self-fertilization; however, they can both accept and produce sperm; it produces both eggs and sperm

• the stem cell that will give rise to the cells that make sperm; always present in the testes; diploid; formed from the primordial germ cell
• reproduces by mitosis, but, some must commit to meiosis at some point in life, becoming a primary spermatocyte, which produces the sperm

• product from primoridial germ cells that divide by mitosis to form cells that begin meiosis (primary oocytes);
• all oogonia commit to meiosis at the same time, forming primary oocyte
• stem cells in follicles that commit before she is born

• occurs about 500 cycles; the cessation of ovulation and menstruation (set end date of a female's reproductive capacity)
• Significance: During this interval, the ovaries lose their responsiveness to FSH and LH, resulting in a decline in estradiol production

• the bleeding and sloughing off of most of the endometrium that was made the month before after fertilization does not occur
• a part of the menstrual cycle
• if fertilizatioin occurs, menses will not
• if the endometrium sloughs off, the embryo goes with it

• Any steroid hormone, such as estradiol, that stimulates the development and maintenance of the female reproductive system and secondary sex characteristics
•  Its immediate role is to stimulate regrowth of the lining of the uterus, in preparation for possible pregnancy. Low levels of estrogen also exert negative feedback on the hypothalamus, keeping blood levels of FSH and LH relatively low

• part of a family of steroid hormones that prepare the uterus for pregnancy.
• the major progestin in mammals

• males: stimulates sperm production by the testes
• secreted by the anterior pituitary
• female: stimulates the growth of an ovarian follicle in the ovary; stimulates the production of eggs by the ovaries

• males: stimulates the testes to secrete androgens--male sex  hormones
• secreted from the anterior pituary
• females: It is the burst of LH that triggers ovulation on about day 14 of the cycle; causes the ruptured follicle to develop into a glandular structure called the corpus luteum; 

• the most important androgen secreted by the testes.
• a steroid hormone required for development of the male reproductive system, spermatogenesis, and male secondary sex characteristics