Navodaya Vidyalaya Samiti – Bhopal Region.
... the other end they joint to a network of tubules called rete testis, which opens to vas efferentia. Vas efferentia leave the testis & open into epididymis which leads to vas deferens. Vas diferentia ascends to the abdomen & it receives a duct from seminal vesicle & opens into urethra via ejaculatory ...
... the other end they joint to a network of tubules called rete testis, which opens to vas efferentia. Vas efferentia leave the testis & open into epididymis which leads to vas deferens. Vas diferentia ascends to the abdomen & it receives a duct from seminal vesicle & opens into urethra via ejaculatory ...
Assortative Fertilization in the Elegans-Group of
... 1980). Two different gene complexes have evolved due to ecological differences in their mating sites. The D. grimshawi-Maui complex populations have a polymorphic inversion sequence on chromosome 4 and lay their eggs on a variety of plants. Other D. grimshawi populations retain the primary ancestral ...
... 1980). Two different gene complexes have evolved due to ecological differences in their mating sites. The D. grimshawi-Maui complex populations have a polymorphic inversion sequence on chromosome 4 and lay their eggs on a variety of plants. Other D. grimshawi populations retain the primary ancestral ...
The evolution of non-ecological reproductive barriers
... (Agrawal, Feder, & Nosil, 2011; Coyne & Orr, 2004). In some cases, sexual selection against hybrids may also be an extrinsic reproductive barrier if sexual displays are environmentally mismatched (Keller & Gerhardt, 2001; Rundle & Nosil, 2005). Intrinsic post-zygotic isolation is the best studied an ...
... (Agrawal, Feder, & Nosil, 2011; Coyne & Orr, 2004). In some cases, sexual selection against hybrids may also be an extrinsic reproductive barrier if sexual displays are environmentally mismatched (Keller & Gerhardt, 2001; Rundle & Nosil, 2005). Intrinsic post-zygotic isolation is the best studied an ...
Development ppt
... Obj. 7: Placentation • The Placenta: a temporary organ that originates from embryonic and maternal tissues –It acts as the respiratory, nutritive, and excretory organ of the fetus ...
... Obj. 7: Placentation • The Placenta: a temporary organ that originates from embryonic and maternal tissues –It acts as the respiratory, nutritive, and excretory organ of the fetus ...
Overview of the Class Arachnida
... d. Most use their chelicerae or pedipalps to capture prey and to break it into very small fragments. Some also use their walking legs to "mince" prey. e. The esophagus is very narrow in all groups and most depend upon a pumping system to obtain fluid food. f. All groups have diverticula or digestive ...
... d. Most use their chelicerae or pedipalps to capture prey and to break it into very small fragments. Some also use their walking legs to "mince" prey. e. The esophagus is very narrow in all groups and most depend upon a pumping system to obtain fluid food. f. All groups have diverticula or digestive ...
Book Reviews 103 Wertheimer`s analysis clearly
... or a byproduct. In Chapter 1, Lloyd cites West-Eberhard’s (1992) definition of an adaptation: a character for which “there is some evidence that it has evolved (been modified during its evolutionary history) in specific ways to make it more effective in the performance of [a particular task], and th ...
... or a byproduct. In Chapter 1, Lloyd cites West-Eberhard’s (1992) definition of an adaptation: a character for which “there is some evidence that it has evolved (been modified during its evolutionary history) in specific ways to make it more effective in the performance of [a particular task], and th ...
earthworm_dissection_review
... Image from: http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/earthworm.html ...
... Image from: http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/earthworm.html ...
asdfs - I Love Science
... Image from: http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/earthworm.html ...
... Image from: http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/animals/earthworm.html ...
Phylum Annelida (segmented worms)
... Not all leeches are bloodsuckers. Many are predators which eat earthworms, etc. The bite of a leech is painless, due to its own ...
... Not all leeches are bloodsuckers. Many are predators which eat earthworms, etc. The bite of a leech is painless, due to its own ...
Reproducton Development
... Scrotum: - sac containing testes - keeps sperm 1-2’ below body temperature -muscles keep scrotum at proper distance to maintain optimum sperm temperature ...
... Scrotum: - sac containing testes - keeps sperm 1-2’ below body temperature -muscles keep scrotum at proper distance to maintain optimum sperm temperature ...
s1-human-reproduction-and-development
... Human reproduction and early development some questions? Where did you come from? What were the cells involved in making you? How did you develop from first cells to birth? ...
... Human reproduction and early development some questions? Where did you come from? What were the cells involved in making you? How did you develop from first cells to birth? ...
Chapter 36 Human Reproduction and Development
... Sperm enter the vagina of the female's reproductive system when strong muscular contractions ejaculate semen from the male's penis during intercourse. Some sperm can exit through the penis before ejac–ulation without the male's knowledge. As a result, sexual activity that does not result in ejaculat ...
... Sperm enter the vagina of the female's reproductive system when strong muscular contractions ejaculate semen from the male's penis during intercourse. Some sperm can exit through the penis before ejac–ulation without the male's knowledge. As a result, sexual activity that does not result in ejaculat ...
Multicellular Organisms Part 2 Reproduction
... and swim faster than single female brine shrimps. Brine shrimp will choose a suitable mate based on size. Large male brine shrimps have more female mates than smaller male brine shrimps and large female brine shrimps are less likely to mate with smaller males. Therefore, larger males should be seen ...
... and swim faster than single female brine shrimps. Brine shrimp will choose a suitable mate based on size. Large male brine shrimps have more female mates than smaller male brine shrimps and large female brine shrimps are less likely to mate with smaller males. Therefore, larger males should be seen ...
Name
... long as the female is alive. Although a female will mate only once, she may produce many fertilized egg masses during her lifetime from this single mating. Fertilization occurs each time a new egg mass is produced by the ovaries until the sperm reserves are depleted. Studies in Florida found that so ...
... long as the female is alive. Although a female will mate only once, she may produce many fertilized egg masses during her lifetime from this single mating. Fertilization occurs each time a new egg mass is produced by the ovaries until the sperm reserves are depleted. Studies in Florida found that so ...
HumanReproduction
... • Tissue through which exchange takes place between mother and embryo • Formed from endometrial tissue and embryonic tissue • Mother’s and embryo’s blood capillaries are very close, but not directly connected, in the placenta. • Materials (O2, food, wastes) pass from mother to embryo, and vice versa ...
... • Tissue through which exchange takes place between mother and embryo • Formed from endometrial tissue and embryonic tissue • Mother’s and embryo’s blood capillaries are very close, but not directly connected, in the placenta. • Materials (O2, food, wastes) pass from mother to embryo, and vice versa ...
Annelids Powerpoint
... Includes sandworms & clamworms Have paddle-like parapodia to move Take in oxygen through parapodia Some are free-swimming predators with strong jaws to feed on small animals • Many live commensally with sponges, ...
... Includes sandworms & clamworms Have paddle-like parapodia to move Take in oxygen through parapodia Some are free-swimming predators with strong jaws to feed on small animals • Many live commensally with sponges, ...
Diapositiva 1 - Holy Family Catholic Regional Division No. 37
... – Once cell division brings the total cell count to around 8, it is called a blastocyst. • Takes 3-5 days for blastocyst to travel through oviduct to uterus. • Blastocyst must implant into endometrium – Occurs 2-4 days after reaching the uterus ...
... – Once cell division brings the total cell count to around 8, it is called a blastocyst. • Takes 3-5 days for blastocyst to travel through oviduct to uterus. • Blastocyst must implant into endometrium – Occurs 2-4 days after reaching the uterus ...
Microsoft Word 97
... The "simplest" actions have two individuals coming together and lining their bodies up so that certain body openings are opposite each other. Hermaphroditic earthworms carry out this action so that one individual releases sperm which enter a special cavity or seminal receptacle of its partner, while ...
... The "simplest" actions have two individuals coming together and lining their bodies up so that certain body openings are opposite each other. Hermaphroditic earthworms carry out this action so that one individual releases sperm which enter a special cavity or seminal receptacle of its partner, while ...
Role of reproductive hormones
... Over the next 6-8 weeks the mother’s uterus returns to its normal size. For mothers who do not breast feed, the menstrual cycle begins again, about 3-4 months after the baby has been born. Milk production A fall in the level of oestrogen and progesterone in blood influences release of a hormone, pro ...
... Over the next 6-8 weeks the mother’s uterus returns to its normal size. For mothers who do not breast feed, the menstrual cycle begins again, about 3-4 months after the baby has been born. Milk production A fall in the level of oestrogen and progesterone in blood influences release of a hormone, pro ...
Human Growth and Development Powerpoint
... • 42 DAYS: The skeleton is complete and reflexes are present. Brain waves (the presence or absence of which are used as a legal means to declare a born person living or dead) can be detected. • WEEK SIX: Now the baby is about 8-11 mm. Although the mother won't be able to feel the baby's kick for ma ...
... • 42 DAYS: The skeleton is complete and reflexes are present. Brain waves (the presence or absence of which are used as a legal means to declare a born person living or dead) can be detected. • WEEK SIX: Now the baby is about 8-11 mm. Although the mother won't be able to feel the baby's kick for ma ...
Slide 1
... Sexual reproduction requires two different parent cells from two separate organisms or from two sexually different parts of a single organism. Sexual reproduction produces off springs that are genetically different from either parent. In simple organisms, sexual reproduction involves transport of ge ...
... Sexual reproduction requires two different parent cells from two separate organisms or from two sexually different parts of a single organism. Sexual reproduction produces off springs that are genetically different from either parent. In simple organisms, sexual reproduction involves transport of ge ...
Segmented Worms (Phylum Annelida)
... 5) Annelids exhibit specialization of the digestive tract. Some of these structures are the pharynx, crop, gizzard, intestine, and accessory glands. 6) Annelids have a closed circulatory system. 7) They have a brain, and a ventral solid nerve cord. There is also a ganglion in each segment. ...
... 5) Annelids exhibit specialization of the digestive tract. Some of these structures are the pharynx, crop, gizzard, intestine, and accessory glands. 6) Annelids have a closed circulatory system. 7) They have a brain, and a ventral solid nerve cord. There is also a ganglion in each segment. ...
Human Reproduction
... Scrotum- pouch of loose skin containing the testes. Houses and air-conditions the testicles by moving and sweating. Semen-the mixture of sperm and fluids released during ejaculation. Semen comprised of sperm, fructose, prostate fluid and oil from Cowper‘s gland. Seminal vesicles-small saclike organs ...
... Scrotum- pouch of loose skin containing the testes. Houses and air-conditions the testicles by moving and sweating. Semen-the mixture of sperm and fluids released during ejaculation. Semen comprised of sperm, fructose, prostate fluid and oil from Cowper‘s gland. Seminal vesicles-small saclike organs ...
Sperm competition
Sperm competition is a term used to refer to the competitive process between spermatozoa of two or more different males to fertilize the same egg during sexual reproduction. Competition can occur when females have multiple potential mating partners. Greater choice and variety of mates increases a female's chance to produce more viable offspring. However, multiple mates for a female means an individual male has decreased chances of producing offspring.Sperm competition is an evolutionary pressure on males, and has led to the development of adaptations to increase males' chance of reproductive success. Sperm competition results in a sexual conflict of interest between males and females. Males have evolved several defensive tactics including: mate-guarding, mating plugs, and releasing toxic seminal substances to reduce female re-mating tendencies to cope with sperm competition. Offensive tactics of sperm competition involve direct interference by one male on the reproductive success of another male, for instance by physically removing another male's sperm prior to mating with a female.Sperm competition is often compared to having tickets in a raffle; a male has a better chance of winning (i.e. fathering offspring) the more tickets he has (i.e. the more sperm he inseminates a female with). However, sperm are not free to produce, and as such males are predicted to produce sperm of a size and number that will maximize their success in sperm competition. By making many spermatozoa, males can buy more ""raffle tickets"", and it is thought that selection for numerous sperm has contributed to the evolution of anisogamy with very small sperm (because of the energy trade-off between sperm size and number). Alternatively males may evolve faster sperm to enable their sperm to reach and fertilize the ovum first. Dozens of adaptations have been documented in males that help them succeed in sperm competition.