Wills, today is the feast day (in the RCC) of St. Turibius of Mogrovejo (1538-1606). Together with Rose of Lima, he is the first known saint of the New World. He 'served' in Peru for 26 years. "Born in Spain and educated for the law, he became so brilliant a scholar that he was made professor of law at the University of Salamanca and eventually became chief judge of the Inquisition at Granada. !!!
He was ordained priest and bishop and sent to Peru, where he found colonialism at its worst. The Spanish conquerors were guilty of every sort of oppression of the native population. Abuses among the clergy were flagrant, and he devoted his energies (and suffering) to this area first."
Haploid cells have only one copy of each chromosome. Most fungi, and a few algae exist as haploid organisms. Plants and other algae switch between a haploid and a diploid or polyploid state, with one of the stages emphasized over the other. This is called alternation of generations. Animals are primarily diploid but produce haploid gametes.
Each of these organisms produces haploid sex cells that can combine to form a diploid zygote. The zygote has genetic information from both cells and soon grows into an embryo.
..... cell that is the male gamete Gametes, also known as sex cells or germ cells, are the cells that come together during fertilization or conception in organisms that reproduce sexually. The gametes of females are called eggs, the gametes of males are called sperm. In diploid species, each contains only one set of chromosomes, meaning that they are haploid. When a sperm and an egg fuse, they form a zygote, a diploid cell, which through multiple divisions and differentiation develops first into an embryo and ultimately into a mature individual.
.....A sperm cell can fertilize
Fertilisation (British English), also spelled fertilization (American English),which is less ambiguously referred to as syngamy, is the process of a sperm fusing with an ovum, which eventually leads to the development of an embryo.
Animal
To deliver the sperm to female, the male inserts his external sexual organ into the opening to vagina, the passage into the female's sexual organ. (This process is a part of copulation.) Once the male ejaculates, a large number of sperms swim toward the ovum. One of them penetrates the ovum's coat, and the ovum is fertilized and the female is pregnant.
..... an egg cell An ovum (or loosely, "egg" or "egg cell") is a female gamete. In higher animals, ova are produced by organs called ovaries.
The word is derived from the Latin word (ovum, plur. ova) for egg
.... to form a zygote
In biology, a zygote is the result of fertilization. That is, two haploid cells - usually (but not necessarily in some organisms) a male sperm cell and a female ovum or ovule - merge into a single diploid cell called the zygote. This cell undergoes multiple cell divisions in gametic and sporic meioses (see biological life cycles) to become an embryo.
See also: pregnancy
..... which can grow into a new organism. Like many other organisms, human offspring is created by this process.
Sperm is carried in the fluid called semen
Semen is the fluid excreted through the male penis, which, during vaginal intercourse, carries sperm into the female, sometimes resulting in pregnancy. Semen is a whitish fluid, slightly viscous, containing water and small amounts of salt, protein, and fructose sugar, and is in itself harmless on the skin or if swallowed. However, semen can be the vehicle for many sexually transmitted diseases, including HIV, the virus that causes AIDS. Any kind of sexual or other skin contact with the semen of a person infected with HIV should be avoided, even by persons already infected with the virus, as this may cause harmful re-infection.
In humans, sperm cells consists of head 0.005 by 0.003 mm and tail 0.05 mm long. The tail flagellate
Flagellates are single-celled protists with one or more flagella, whip-like organelles often used for propulsion. Originally they were grouped together as the class or phylum Mastigophora, but the different lines do not appear particularly closely related. These include:
...., which propels the sperm cell. The cell is characterized by a minimum of cytoplasm Cytoplasm is the viscid, semifluid matter contained within the plasma membrane of a cell. In contrast to the protoplasm, however, the cytoplasm does not include the cell nucleus. The watery or aqueous component of the cytoplasm is the cytosol, which includes ions and soluble macromolecules, for example enzymes. The insoluble constituents of the cytoplasm include the organelles and the cytoskeleton, which gives to the cytoplasm a gel-like structure and consistency. While all cells possess a cytoplasm, cells from the different biological domains and kingdoms can differ widely in the characteristics of their cytoplasms.
Sperm cells were first observed by Antoni van Leeuwenhoek
Anton van Leeuwenhoek (October 24, 1632 - August 26, 1723) was a tradesman and scientist from Delft, in the Netherlands. He is best known for his contribution to improvement of the microscope and his contributions towards the establishment of cell biology. Using his handcrafted microscope he was the first to observe and describe muscles fibres, bacteria, spermatozoa and blood flow in capillaries (small blood vessels).
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(1) Acrosome In sperm cells of many higher animals, the Acrosome develops over the anterior half of its head. It is a cap-like structure derived from the Golgi apparatus. It contains enzymes needed to penetrate the tough outer covering of the ovum.
When the sperm comes in contact with that covering (the egg jelly), the acrosome reaction takes place, during which actin polymerizes to form the acrosomal process; also, the acrosomal vesicle fuses with the plasma membrane of the egg cell, and digestive enzymes are released from the sperm to digest the egg jelly and give access to the egg.
... (2) Cell membrane
A component of every biological cell, the cell membrane (or plasma membrane) is a thin and structured layer of lipid and protein molecules, which surrounds the cell. It separates a cell's interior from its surroundings and controls what moves in and out.
In animal cells, the cell membrane establishes this separation alone, whereas in yeast, bacteria and plants an additional cell wall forms the outermost boundary, providing primarily mechanical support. The plasma membrane is only about 10 nm thick and may be discerned only faintly with a transmission electron microscope. One of the key roles of the membrane is to maintain the cell potential.
... (3) Nucleus
In cell biology, the nucleus is an organelle, found in most eukaryotic cells, which contains most of the cell's genetic material. Nuclei have two primary functions:
to control chemical reactions within the cytoplasm
to store information needed for cellular division
Structure
It is surrounded by a double membrane forming the nuclear envelope, about 30 nm wide. This selectively allows molecules to enter and leave the nucleus, and separates chemical reactions taking place in cytoplasm from reactions happening within the nucleus. The outer membrane has ribosomes. The inner and outer membrane fuse at regular spaces, forming nuclear pores.
..... (4) Mitochondria
A mitochondrion is an organelle found in the cells of most eukaryotes. Mitochondria are sometimes described as "cellular power plants" because their primary function is to manufacture adenosine triphosphate (ATP), which is used as a source of energy.
The number of mitochondria found in different types of cells varies widely. At one end of the spectrum, the Trypanosome protozoan has one large mitochondrion; by contrast, human liver cells normally have between one and two thousand each. Mitochondria can occupy up to 25% of cell cytosol.
... (5) Tail (flagella The flagellum (plural: flagella) is a propulsive structure used by many single-celled organisms to move through a liquid medium. There are three main varieties of flagellum; the bacterial flagellum (a helical filament that rotates like a screw), archaeal flagellum (similar but nonhomologous to the bacterial flagellum), and the eukaryotic flagellum (a whip-like structure that lashes back and forth).
Why Do Girls' Breasts Get Bigger?
There are many factors that influence growth of breasts. These include nutrition and genetics, both because of hormone stimulation. Breast growth is one of the important things that happens during puberty. The pubertal hormones produced by the pituitary gland (located in the brain and responsible for producing a variety of hormones), play a critical role. One of the earliest signs that puberty has begun is enlargement of the breasts as a result of increased production of ovarian estrogen stimulated by these pituitary hormones. Boys also often experience breast enlargement during the early stages of their pubertal growth spurt, but their breasts usually shrink in size after one or two years. As long as estrogen continues to be secreted in females, breasts will grow and/or maintain their size. Breasts may also enlarge slightly in women taking birth control pills or, after menopause, estrogen-replacement pills. Naturally, breasts enlarge during pregnancy as a result of marked increase in estrogen secretion. Girls with poor diets and weight loss may notice that their breasts get smaller. If these girls improved their nutrition, their breasts would enlarge to their previous size.
When Should A Girl’s Breasts Start Growing?
Girls often worry when they notice that their friends' breasts are enlarging and theirs are not. It is important to understand that there is a lot of variation in the normal timing of breast growth. For example, it is normal for breasts to start growing as early as nine years of age and it is also normal if they do not begin growing until 14 years of age. In general, a girl will experience breast growth within one year of the time her mother first noticed her own breasts growing (timing is even closer among sisters). It may be very interesting and helpful to discuss this with them. Most women remember how old they were when they first wore a bra, just as they remember their age at their first menstrual period. These two events are closely related with breast growth generally beginning about a year before menses. Because nutrition, exercise, and health (both physical and emotional) can all affect hormone levels, family history of timing of breast growth (and menses) provides only a rough guess about when it will actually begin. Another thing that girls should know about their breast growth is that it is not always the same for both breasts. This should not be cause for worry because there is usually catch-up by the time breasts are fully grown, which can take a few years. In many girls, however, one breast remains slightly larger than the other. This is rarely noticeable to anyone else!
How Big Should Breasts Be?
There is no good answer to this question, as we all come in different sizes. Some of us are tall and some short. Similarly, some girls have large, medium, or small breasts. Nonetheless, many girls are unhappy because they think their breasts are too small or too large. Attitudes about breast size are often influenced by fashions. In the Flapper days (1920s), it was considered desirable to have small breasts, as was the case in the l960s when fashion models began to look emaciated. With the arrival of the Wonder Bra, it again became fashionable to have larger breasts. From a health perspective, there is no ideal breast size. Breast size bears no relationship to breast cancer or ability to nurse an infant. There are surgical procedures available to increase or decrease the size of breasts. These are major operations and they should not be entered into without considerable thought and extensive information, as they have possible serious drawbacks and complications. Padded bras are safer alternatives for those who want their breasts to appear larger. Also remember that you have time on your side as breasts continue to grow, especially during puberty and pregnancy. Improving nutrition may also contribute to increased breast volume.
Can Teenage Girls Get Breast Cancer?
Breast cancer is almost unheard of in adolescence. On the other hand, breast lumps are common at this time of life. This apparent contradiction is explained by the fact that teenagers often get cysts or tumors in their breasts that are not cancerous. These result from sensitivity to estrogen. Most of the time, these kinds of lumps will disappear on their own, but it is always a good idea to have them checked by a doctor. Some girls have many small nodules in their breasts, a condition that used to be called fibrocystic disease. This term is no longer used because of current awareness that it is not a disease, but a variation of normal. When a lump is found, doctors will usually wait up to three menstrual cycles before taking any action, as they most likely will disappear. Mammograms, which are x-rays of the breasts, are not generally helpful in teenagers. We encourage teenagers to learn and practice self-breast examination techniques so this will become a health habit by the time they reach their fifties when your chance of having breast cancer increases. Use of birth control pills does not increase the risk of breast cancer during adolescence and, in fact, has been shown to lower the risk of developing noncancerous breast tumors.
Is It Normal For There To Be Discharge Coming Out Of My Breasts?
The nipple is the exit point of numerous tiny ducts that lead from the interior of the breast where glands produce milk. Therefore, the most common discharge occurs when these glands are stimulated, as is true at the time of delivery of a baby. As long as sucking continues, milk will be produced and discharged through the nipple. Interestingly, vigorous rubbing of the nipple can also cause a discharge of milk. If the discharge is bloody or pus-like, it may indicate one of the rare serious conditions like an infection or tumor. Similarly, absence of menses associated with a nipple discharge may indicate a tumor of the pituitary gland or may result from certain medications. Obviously, a physician should be consulted whenever there is a nipple discharge in order to figure out its cause.