In gestational surrogacy, an egg is removed from the intended mother or an anonymous donor and fertilized with the sperm of the intended father or anonymous donor. The fertilized egg, or embryo, is then transferred to a surrogate who carries the baby to term. It's a woman who gets artificially inseminated with the father's sperm. She then carries the baby and delivers it for you and your partner to raise. A traditional surrogate is the baby's biological mother. That's because it was her egg that was fertilized by the father's sperm. Donor sperm can also be used.

The external genitalia is the accessory structures of the female reproductive system that are external to the ******. They are also referred to as the vulva or pudendum. The external genitalia includes the ***** majora, mons pubis, ***** minora, ********, and glands within the vestibule. 

The external genital organs include the mons pubis, ***** majora, ***** minora, Bartholin glands, and ********. The area containing these organs is called the vulva.

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The external genital organs have three main functions:

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  Enabling sperm to enter the body

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  Protecting the <a data-preview-itemid="6d8b77d9eb5c4f779282b857e565c26d" href="https://www.msdmanuals.com/home/women-s-health-issues/biology-of-the-female-reproductive-system/female-internal-genital-organs">internal genital organs</a> from infectious organisms

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  Providing sexual pleasure

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The mons pubis is a rounded mound of fatty tissue that covers the pubic bone. During <a data-preview-itemid="3c6136d2a6a64f3089975d890cade1bd" href="https://www.msdmanuals.com/home/women-s-health-issues/biology-of-the-female-reproductive-system/puberty-in-girls">puberty</a>, it becomes covered with hair. The mons pubis contains oil-secreting (sebaceous) glands that release substances that are involved in sexual attraction (pheromones).

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The ***** majora (literally, large lips) are relatively large, fleshy folds of tissue that enclose and protect the other external genital organs. They are comparable to the ******* in males. The ***** majora contain sweat and sebaceous glands, which produce lubricating secretions. During puberty, hair appears on the ***** majora.

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The ***** minora (literally, small lips) can be very small or up to 2 inches wide. The ***** minora lie just inside the ***** majora and surround the openings to the ****** and urethra. A rich supply of blood vessels gives the ***** minora a pink colour. During sexual stimulation, these blood vessels become engorged with blood, causing the ***** minora to swell and become more sensitive to stimulation. 

The area between the opening of the ****** and the ****, below the ***** majora, is called the perineum. It varies in length from almost 1 to more than 2 inches (2 to 5 centimeters).

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The ***** majora and the perineum are covered with skin similar to that on the rest of the body. In contrast, the ***** minora are lined with a mucous membrane, whose surface is kept moist by fluid secreted by specialized cells.

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The opening to the ****** is called the introitus. The vaginal opening is the entryway for the ***** during sexual intercourse and the exit for blood during menstruation and for the baby during birth.

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When stimulated, Bartholin glands (located beside the vaginal opening) secrete a thick fluid that supplies lubrication for intercourse.

The opening to the urethra, which carries urine from the bladder to the outside, is located above and in front of the vaginal opening.

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The ********, located between the ***** minora at their upper end, is a small protrusion that corresponds to the ***** in the male. The ********, like the *****, is very sensitive to sexual stimulation and can become erect. Stimulating the ******** can result in an orgasm.

Y, is dominant over the recessive green version, y. Y always wins out over y: When a pea plant makes seeds, only one of its two copies of the color gene goes into the seed. So if you have two green pea plants, each can only pass a green version. Mendel's gene involved in pea color decides whether the chlorophyll in the pea will be broken down or degraded. When this gene isn't working, the chlorophyll stays around and the pea is green. So in this case the recessive trait is indeed due to a broken gene.

The pyramid of biomass in a pond is generally inverted because the biomass of fish exceeds that of phytoplankton and the number of big fish eating the small fish is also greater than the small ones.

Also, in the pyramid of numbers, the number of insects feeding on a big tree is far greater than the tree. Now the number of small birds depending on the insects and the number of larger birds eating the smaller ones also increases in the order. 

The existence of life on the planet earth is mainly based on certain functions and processes. There are certain basic vital processes which are essential for an organism to stay healthy and to maintain the proper functioning of the body organ system, which all are necessary for survival. These basic essential activities performed by an organism are called as life processes.

In GIFT, both sperm and unfertilised oocytes are transferred into fallopian tubes, after which fertilisation takes place in vivo (inside the body of the female). The success rate of this technique is 27–30%.Because the eggs and sperm are placed into the fallopian tubes before conception, there's no way to know if fertilization has taken place prior to transfer.

In ZIFT, The zygote or the early embryo, up to 8 blastomeres, is transferred into the fallopian tube. With ZIFT the sperm and egg are mixed together in the laboratory, and given time to fertilize before being transferred to the fallopian tubes thus lowering the number of eggs used and correspondingly the chances for multiple pregnancy.

In 1928, Frederick Griffith conducted a series of experiments with <i>Streptococcus pneumoniae</i>. When <i>Streptococcus pneumoniae</i> bacteria are grown on a culture plate, some produce smooth shiny colonies (S), while others produce rough colonies (R). Mice infected with S strain (virulent) die from pneumonia, but those infected with R strain do not develop pneumonia.

<i>S Strain → Inject into mice → Mice die</i>

<i>R strain → Inject into mice → Mice live</i>

Griffith killed the bacteria by heating them. When the heat-killed S strain bacteria were injected into mice, they did not kill the mice. When a mixture of heat-killed S strain and live R strain bacteria was injected into mice, the mice died. Griffith recovered living S bacteria from the dead mice.

<i>S Strain (heat killed) → Inject into mice → Mice live</i>

<i>S Strain (heat killed) + R strain (live) → Inject into mice → Mice die</i>

Griffith concluded that the R strain bacteria somehow were transformed by the heat-killed S strain bacteria. This must be due to the transfer of the genetic material. But he could not define the biochemical nature of genetic material.

Placenta refers to the temporary vascular organ found in mammals, which attaches the fetus to the uterus of the mother during pregnancy.

After pollen grains land on the stigma, a pollen tube grows from the pollen grain, through the style, and into the ovary. Sperm cells inside the pollen grain travel down the pollen tube and into the ovary which contains the ovules. Fertilization occurs when one of the sperm cells fuses with the egg inside of an ovule. For fertilization to occur in angiosperms, pollen has to be transferred to the stigma of a flower: a process known as pollination. Gymnosperm pollination involves the transfer of pollen from a male cone to a female cone.  After fertilization, the zygote divides to form the embryo and the fertilized ovule forms the seed.

Darwinian evolution proposes that all living organisms are formed by descent with modification from a common ancestor or cell. ... Endosymbiosis explains the origins of Eukaryotic cells by the theory that one prokaryotic cell absorbed another prokaryotic cell creating a cell with multiple membranes. Two symbiotic organisms become endosymbiotic when one species is taken inside the cytoplasm of another species, resulting in genome fusion. Genome fusion, by endosymbiosis, between two species, one an Archaea and the other a Bacteria, has been proposed as responsible for the evolution of the first eukaryotic cells.

S-shaped growth curve (sigmoid growth curve) A growth pattern in which an organism's population density rises slowly originally in a fresh setting, in a favorable acceleration stage ; then rises quickly approaching an exponential growth rate as in the J-shaped curve ; but then decreases in a negative acceleration stage until the population stabilizes at zero growth rate.

Ribosome is the site where protein synthesis takes place. Ribosomes bind mRNA, help in positioning amino acids and catalyse the joining of amino acids to form peptide bond by its peptidyl transferase activity. Ribosomal RNA of the larger sub-unit of ribosome act as enzyme and catalyse the formation of peptide bond between amino acids. Energy from ATP or GTP is required for the translocation of ribosome to the next codon in mRNA. 

A histone is a protein that provides structural support to a chromosome. In order for very long DNA molecules to fit into the cell nucleus, they wrap around complexes of histone proteins, giving the chromosome a more compact shape. Some variants of histones are associated with the regulation of gene expression. Their function is to package DNA into structural units called nucleosomes. Histones are the main proteins in chromatin. Chromatin is a combination of DNA and protein which makes up the contents of a cell nucleus. Because DNA wraps around histones, they also play a role in gene regulation.

We can grow banana and ginger by vegetative propagation method.

Banana and ginger both grow from under ground structures a corm and a rhizome respectively.

The age at which the *** hormones begin to be produced and the boy and girl become sexually mature (able to reproduce) is called puberty. Females attain puberty at an age of 10-12 years.

Puberty is the time when the juvenile body of a person starts sexual maturation.

Changes such as appearance of pimples on face, growth of thick hair in armpits and genital areas occur in both boys and girls.

The changes observed in boys during puberty are: Hair grows under armpits, pubic region between the thighs, chest and face. Body becomes more muscular due to the development of muscles. The voice deepens. Chest and shoulder broaden. The ***** and testes become larger. Feelings and sexual drives associated with adulthood begin to develop.

The changes observed in girls during puberty are: Hair grows under armpits and pubic region. Mammary glands develop and breasts become enlarged. The hips broaden and extra fat is deposited in various parts of the body like hips and thighs. Fallopian tubes, uterus and ****** enlarge. Ovaries start to release eggs and menstruation starts.

The testes and ovaries are the male and female *** organs which produce *** cells for sexual reproduction in human beings. The function of testes is to make *** cells called sperms and to make *** hormone called testosterone. The function of the ovaries is to make mature female *** cell called ova or egg and also to make female *** hormones called oestrogen and progesterone.

The sexual mode of reproduction means that germ-cells from two individuals have to join together either by the external release of germ-cells from the bodies of individuals, as happens in flowering plants. Or by two individuals joining their bodies together for internal transfer of germ-cells for fusion, as happens in many animals. If animals are to participate in this process of mating, their state of sexual maturity must be identifiable by other individuals. Many changes during puberty, such as new hair-growth patterns, are signals that sexual maturation is taking place.

On the other hand, the actual transfer of germ-cells between two people needs special organs for the sexual act, such as the ***** when it is capable of becoming erect. In mammals such as humans, the baby is carried in the mother’s body for a long period, and will be breast-fed later.