...one produces two sperm nuclei, and the...
...to transfer the sperm nuclei to the...
...to form two sperm nuclei that move...
...Egg and one sperm form the zygote,...
...and the second sperm form the endosperm,...
...more than one sperm. Endosperm development After...

...rise to male (sperm-containing) gametophytes. In contrast...
...one or two sperm into the female...
...gymnosperms have flagellated sperm cells, the sperm...
...sperm cells, the sperm in most gymnosperms...
...and pteridophytes, flagellated sperm must swim through...
...are ready, two sperm cells have developed...
...one of the sperm nuclei fuses with...
...it discharges two sperm cells into the...
...double fertilization, one sperm unites with the...

...produce gametes - sperm and eggs. Fertilization...
...male gametophytes are sperm-producing structures called pollen...
...style and discharges sperm into the embryo...
...will eventually form sperm. The tube cell,...
...tube, which delivers sperm to the egg....
...to form two sperm cells. In most...
...by ensuring that sperm and eggs come...
...to produce two sperm, the male gametophyte....
...and discharges two sperm within the embryo...
...embryo sac. Both sperm fuse with nuclei...
...embryo sac. One sperm fertilizes the egg...
...zygote. The other sperm combines with the...
...union of two sperm cells with different...
...able to isolate sperm cells and eggs...
...more than one sperm cell. In plants,...
...that mechanically impedes sperm. 6. The ovule...

...Spermatids D. Mature sperm E. More than...
...(how many?) functional sperm(s); one primary oocyte...

...an egg or sperm contains an embryo...
...the nuclei of sperm and egg. The...
...gametes (egg and sperm) are highly specialized...
...Contact of the sperm with the egg’s...
...urchin egg and sperm encounter each other...
...egg attracts the sperm, which swims toward...
...head of the sperm comes into contact...
...tip of the sperm, discharges its contents...
...fertilized only by sperm of the same...
...same species. The sperm and egg plasma...
...fuse, and the sperm nucleus enters the...
...seconds after the sperm binds to the...
...depolarization prevents additional sperm from fusing with...
...egg by multiple sperm. Fusion of egg...
...of egg and sperm plasma membranes triggers...
...entry of additional sperm. Another enzyme clips...
...with any attached sperm. The fertilization envelope...
...reaction to occur. Sperm binding activates a...
...minutes after the sperm enters the egg,...
...the egg, the sperm nucleus and egg...
...through which the sperm can move toward...
...act to increase sperm motility. In humans,...
...this enhancement of sperm function requires about...
...during ovulation. A sperm must migrate through...
...Binding of the sperm cell to a...
...cell to a sperm receptor on the...
...acrosome enable the sperm cell to penetrate...
...proteins on the sperm bind to the...
...binding of the sperm cell to the...
...the egg and sperm membranes fuse, the...
...fuse, the entire sperm, tail and all,...
...body of the sperm’s flagellum generates the...
...nuclei of mammalian sperm and egg do...
...both egg and sperm nuclei disperse. The...
...12–36 hours after sperm binding in mammals....
...side where the sperm entered, which is...
...the side of sperm entry moves toward...
...the side opposite sperm entry are now...
...the side opposite sperm entry, the gray...
...both eggs and sperm, which has advantages...
...the egg and sperm nuclei before fusion...

...gamete is the sperm, which is usually...
...no fusion of sperm and egg. Reproduction...
...produce eggs or sperm without meiosis. Male...
...receives and donates sperm, resulting in twice...
...new male, producing sperm and defending the...
...fertilization bring together sperm and eggs of...
...the union of sperm and egg, play...
...fertilization, eggs and sperm are both released...
...with internal fertilization, sperm are deposited in...
...to allow the sperm to swim to...
...ensure that mature sperm and eggs encounter...
...life that enables sperm to reach an...
...organs that deliver sperm and receptacles for...
...and receptacles for sperm storage and transport....
...for ova and sperm is often established...
...making eggs or sperm. The simplest reproductive...
...gonads; eggs and sperm develop from undifferentiated...
...In the male, sperm develop in a...
...storage. During mating, sperm are ejaculated into...
...sac in which sperm may be stored...
...the repository for sperm during copulation. The...
...gonads that produce sperm and reproductive hormones,...
...products essential to sperm movement, and ducts...
...to carry the sperm and glandular secretions....
...seminiferous tubules, where sperm are produced. Leydig...
...breeding seasons, interrupting sperm maturation. Some mammals...
...enough to allow sperm maturation—such as monotremes,...
...the testes, the sperm pass through the...
...three weeks for sperm to pass through...
...through this duct, sperm complete their maturation...
...and become motile. Sperm acquire the ability...
...system. Ejaculation propels sperm from each epididymis...
...energy source for sperm), a coagulating enzyme,...
...and citrate, a sperm nutrient. Prostate problems...
...also carries some sperm released before ejaculation....
...containing 70–130 million sperm. The main shaft...
...depression that receives sperm at the back...
...types of gametes. Sperm are small and...
...embryo. Egg and sperm development involves distinct...
...and development of sperm cells, is a...
...of millions of sperm are produced each...
...For a single sperm, the process takes...
...give rise to sperm. As spermatogonia differentiate...
...progresses, the developing sperm cells move from...
...The structure of sperm fits its function....
...that help the sperm penetrate to the...
...ovulation. When a sperm penetrates the oocyte,...
...Spermatogenesis produces mature sperm from precursor cells...
...that nourish developing sperm. LH regulates Leydig...
...with 70–130 million sperm per milliliter. The...
...thus protecting the sperm and increasing their...
...in place until sperm reach the cervix....
...semen, and the sperm begin swimming through...
...fertilization by keeping sperm and egg apart;...
...barriers that keep sperm and egg apart....
...24–48 hours and sperm for as long...
...of preventing fertilization. Sperm may be present...
...contraception that block sperm from meeting the...
...mucus to block sperm from entering the...
...deferens to prevent sperm from entering the...
...therapy may increase sperm or egg production;...
...body. Unused eggs, sperm, and embryos from...
...are mixed with sperm in culture dishes,...
...uterus. If mature sperm are defective, scarce...
...restored by intracytoplasmic sperm injection (ICSI). In...
...head of a sperm is drawn up...

...gametes (eggs and sperm). Fertilization results in...
...protuberance that delivers sperm to the female...
...to produce two sperm cells, which remain...
...it releases the sperm cells near the...
...to produce two sperm. Directed by a...
...discharges its two sperm near or within...
...pollen tube. Both sperm fuse with nuclei...
...embryo sac. One sperm fertilizes the egg...
...zygote. The other sperm combines with the...
...union of two sperm cells with different...
...able to isolate sperm cells and eggs...
...more than one sperm cell. In plants,...
...may mechanically impede sperm. In maize, this...
...after the initial sperm fusion with the...
...by ensuring that sperm and eggs come...

...rise to male (sperm-containing) gametophytes. Seed plants...
...it delivers two sperm into the female...
...plants have flagellated sperm cells that swim...
...the archegonium. The sperm of most seed...
...the ovule. The sperm of some gymnosperm...
...lost in the sperm of most gymnosperms...
...seed? When a sperm fertilizes an egg...
...to form two sperm and a tube...
...the ovule. Two sperm are discharged into...

...structure of flagellated sperm of charophytes and...
...land plants with sperm is very similar....
...gametes, egg and sperm, by mitosis. The...
...of egg and sperm during fertilization forms...
...produce and release sperm into the environment....
...living plants, the sperm have flagella and...
...produce many flagellated sperm. Some bryophyte gametophytes...
...female gametophytes. Flagellated sperm swim through a...
...to the archegonia. Sperm swim into the...
...than bryophytes. The sperm of ferns and...
...to their swimming sperm and fragile gametophytes,...
...and details of sperm ultrastructure indicate that...

...rise to male (sperm-containing) gametophytes. Seed plants...
...one or two sperm into the female...
...plants have flagellated sperm cells that swim...
...pollen grains. The sperm of seed plants...
...the ovule. The sperm of some gymnosperm...
...seed When a sperm fertilizes an egg...
...of egg and sperm follows. The pine...
...to form two sperm and a tube...
...the ovule. Two sperm are discharged into...
...dont see flagellated sperm. Answer for mini...
...union of a sperm cell with two...
...before gymno- naked -sperm - seed (progymnosperm...