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Salt Tolerance in Tomatoes
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On Cell Respiration
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JUNIORS STUDY TEAMS
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Reproduction Wiki - Made by Seniors
by the Class of 2010
Three roles of testosterone in males are: Develop prostrateresponsible for sexual drive and excreting sperm with semen through the urethra, determine gender, and differentiation between male and female bodies during the prenatal stage (between 7 and 12 weeks of gestation)
In Vitro fertilization (IVF) is an infertility treatment different from artificial insemination (implantingthe sperm in the women’s womb and everything else is natural). During IVF the sperm fertilizes the egg out side of the body in a lab; the offspring of this type of treatment are often referred to as test tube babies. Once the embryo(s) form theyare placed in the uterus and the pregnancy goes on as if it were natural.
Spermatogenesis is the process when spermatogonia become a fully grown sperm. This occurs in the tubules of the testes in males.The outer layer of spermatogonia divides by mitosis to form new cells.Spermatogenesis occurs by meiosis. A cell in the tubules called the spermatogonium. In interphase the chromosomes are replicated forming sister chromatids, this causes the cell to increase in size and is called primary spermatocytes. This cell divides once after prophase, metaphase and divides during telophase to form two diploid cells called secondaryspermatocytes. These cells then undergo interphase without the replication part, prophase, metaphase, anaphase and then divides in telophase again by cytokinesis forming four haploid cells called spermatids. These spermatids go through a metamorphosis phase to become mature spermatozoa. This occurs because they are nursed by sertoli cells which help in development. Once
and formed with a tail, sperms detach from the sertoli cells and are carried out through the
-in the female fetus ovaries, oogonia cells are divided through mitosis to make more of these cells.
grow into bigger cells= primary oocytes
-these new cells start meiosis but stop at prophase 1
-primary oocytes and follicle cells form a primary follicle
-when the female baby is born there is 400,000 primary follicles in her ovaries
-during her period, primary follicles start to develop and the primary oocyte finishes meiosis 1 where it formed to hapliod daughter nuclei
-the cytoplasm of the primary oocyte develops unequally, forming a secondary oocyte and a small polar body
the Secondary oocyte starts second division of meiosis but stops at prophase II
-the follicle cells reproduce fast and follicle fluid is formed
-when the mature follicle bursts at the time of ovulation, the released egg is still a secondary oocyte.
-after fertilization, the secondary oocyte completes the second division of meiosis to form an ovum with the sperm nucleus already inside.
-Polar bodies do not develop into eggs; they degenerate.
11.4.6: Labeled diagram of a mature sperm and mature egg: (RUSHKA)
11.4.10 Outline the role of HCG in early pregnancy (ANGELA)
Human Chorionic Gonadotrophin, an embryonic hormone maintaining secretion of progesterone. This is through the first trimester by the uterus lining. The level of HCG in maternal blood is so high that it is present in the urine, which allows it to be detected for pregnancy tests
11.4.11 Outline early embryo development up to the implantation of the blastocyst (ANGELA)
Embryo development starts off with fertilization creating a morula, a bunch of cells in a ball shape. This “ball” reaches the uterus 4 days later. Up till the 7th day, unequal divisions occur which causes the space in the middle of the morula to fill with fluid, which is the blastocyst. The trophoblast, outer cells of blastocyst, imbeds itself in the endometrium.
Materials are exchanged through placenta from mother to infant.The materials exchanged between the mother and the fetuses are:
Nutrients: Oxygen, Proteins, Enzymes, etc.
Waste Products: CO2, Urea, metabolic wastes
Spermatogenesis: occurs in the seminiferous tubules. Spermatogonia are the cells that later becomes gamete cells, sperm cells. The have 46 chromosomes. Then through mitosis primary spermatocyte is created. Next meisosis occurs and two daughter cells each with 23 chromosomes are produced called secondary spermatocytes. They divide again and produce 4 spermatids. The spermatids then differentiate into the sperm cells.
Oogenesis: is the maturation and differentiation of the ova in the ovary. The oogeneis contains all the DNA and information necessary to initiate and maintain metabolism and development. The egg develops a complex cytoplasm while the sperm merely is mobile DNA. Also oogenic meiosis has the same volume of oocyte cytoplasm in each new cell produced rather than splitting it like in spermatogeneis. A few days before ovulation the birth of the ova is called the primary oocyte it later develops over into the graffian follicle. The LH hormone peak triggers the maturation of the cell.
Primary oocyte graffian follicle.
- part of the male reproductive system. It is a long tube that is coild at the back of each of the male's testicles. Necessary for helping transport/store the sperm produced in the testes. It also helps matures the sperm and when aroused, the coil contracts and pushs the sperm out to the vas defrenes.
siminal vesicle- a pouch taht attaches to the vas defrenes at the bottom of the bladder. It produces fructose that gives sperm cells energy to move.
prostate gland- a walnut sized ball located under the bladder infront of the rectum. It ejaculates extra fluids when males are aroused
FH: initiates spermatogenesis, production of androgen binding proteins by the Sertoli cells, helps secrete testosterone, increase the production of spermatozoa, promotes spermatogenic cells
Testosterone: maintenance of reproductive tract, initiates spermatogenesis, excreted by androgen binding proteins, maintain spermatogenesis
LSH: suppress the proapoptotic signals and therefore promote spermatogenic cell survival
Ethical Issues with IVF:- The embryo that has to be implanted into the female is technically already a person because it already has genetic coding. The question that comes up is whether or not we chose if the person lives or not depending on if someone changes their mind on getting in vitro fertilization.- The wrong embryo can be implanted into a person creating a mix-up. - People might want to choose what health traits they want in their babies. This could be good or bad depending on which trait but it’s still a problem because technically that’s not allowing nature to take its course.- Older women such as women in their 50’s or 60’s may choose t have IVF. This is dangerous because the person’s body isn’t as prepared as it was to care for and nurture a child. This could be harmful for the embryo if they are not receiving enough vitamins and nutrients.Light micrograph of testis tissue
11.4.12 ( LIANE)
Explain how the structure and functions of the placenta, including its hormonal role in secretion of estrogen and progesterone, maintain pregnancy.
The placenta allows the mother to nutrients to the baby or fetus. The placenta also allows gas exchange and waste elimination. The structure aids in these processes because of the presence of the umbilical cord. The gas exchange, in particular, takes place in the arteries and veins present in the umbilical cord. The placenta also aids in production of hormones. Progesterone is a key hormone for maintaining pregnancy. It helps the fetus develop while in the mother’s womb. Estrogen is the hormone responsible for allowing an increased transfer of nutrients from the mother to the baby. This explains why the mother’s glucose levels have a sharp increase during pregnancy.
State that the fetus is supported and protected by the amniotic sac and amniotic fluid.
The fetus is supported by the amniotic sac and the amniotic fluid. The amniotic sac encloses the baby in the mother’s womb. The fetus grows in the amniotic sac, which is composed of membranes called amnion and chorion. The amniotic fluid surrounds the amniotic sac, which is what is commonly referred to as the “water”. This fluid supports the baby in that the fluid prevents the baby from bumping roughly against the uterine wall. The fluid acts like a cytoplasm, where the baby can absorb nutrients from the mother. This fluid regulates temperature in the
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