Reproductive System and Development - GED Science

Ovulation, or the release of the egg from its follicle, is initiated by a temporary spike in estradiol (estrogen) levels. This positive feedback event is referred to as the luteal surge.

Menstruation follows ovulation. Gastrulation is a phase of development during which the primary germ layers are generated in an embryo, and is not related to the female cycle.

There are several stages of embryonic development. The first stage is the zygote, which is simply a single cell formed after the sperm fuses with the egg. The cell then begins to divide, creating more cells without actually expanding in size. This process is called cleavage and the embryo is now call a morula. Eventually, the cells orient such that they form a ball with a hollow center and begin to expand in total size. This stage is known as the blastula or blastocyst stage. During this stage, the embryo will enter the uterus and implant into the uterine wall. As the cells continue to divide and orient, the blastocyst develops an inner cell mass, which will be become the new organism. The cells in this area begin to differentiate into the different germ layers through a process known as gastrulation; the resulting embryo is known as a gastrula.

Following gastrulation, the three primary germ layers are formed. They are the ectoderm, the mesoderm, and the endoderm. The ectoderm develops into the skin and the nervous system. The mesoderm develops into the bones and muscle. The endoderm develops into the lining of the digestive tract and most internal organs.

Spermatozoa formation is accomplished in the seminiferous tubules in the testes. Once created, the spermatozoa are taken to the epididymis for storage and maturation. During ejaculation, the sperm is expelled through the vas deferens then through the urethra and out of the penis.

The germ cells (eggs/oocytes and sperm) contain only one copy of each chromosome. This reduction in the amount of DNA occurs through meiosis. Most cells in the body contain two copies of each chromosome and are considered diploid. Since they only contain ne copy of each chromosome, germ cells are considered haploid.

Neurons and lymphocytes (white blood cells) contain two copies of each chromosome; they are diploid. Erythrocytes (red blood cells) do not have nuclei, and do not contain any genetic material.

Ovulation, or the release of the egg from its follicle, is initiated by a temporary spike in estradiol (estrogen) levels. This positive feedback event is referred to as the luteal surge.

Menstruation follows ovulation. Gastrulation is a phase of development during which the primary germ layers are generated in an embryo, and is not related to the female cycle.

There are several stages of embryonic development. The first stage is the zygote, which is simply a single cell formed after the sperm fuses with the egg. The cell then begins to divide, creating more cells without actually expanding in size. This process is called cleavage and the embryo is now call a morula. Eventually, the cells orient such that they form a ball with a hollow center and begin to expand in total size. This stage is known as the blastula or blastocyst stage. During this stage, the embryo will enter the uterus and implant into the uterine wall. As the cells continue to divide and orient, the blastocyst develops an inner cell mass, which will be become the new organism. The cells in this area begin to differentiate into the different germ layers through a process known as gastrulation; the resulting embryo is known as a gastrula.

Following gastrulation, the three primary germ layers are formed. They are the ectoderm, the mesoderm, and the endoderm. The ectoderm develops into the skin and the nervous system. The mesoderm develops into the bones and muscle. The endoderm develops into the lining of the digestive tract and most internal organs.

Spermatozoa formation is accomplished in the seminiferous tubules in the testes. Once created, the spermatozoa are taken to the epididymis for storage and maturation. During ejaculation, the sperm is expelled through the vas deferens then through the urethra and out of the penis.

The germ cells (eggs/oocytes and sperm) contain only one copy of each chromosome. This reduction in the amount of DNA occurs through meiosis. Most cells in the body contain two copies of each chromosome and are considered diploid. Since they only contain ne copy of each chromosome, germ cells are considered haploid.

Neurons and lymphocytes (white blood cells) contain two copies of each chromosome; they are diploid. Erythrocytes (red blood cells) do not have nuclei, and do not contain any genetic material.

Ovulation, or the release of the egg from its follicle, is initiated by a temporary spike in estradiol (estrogen) levels. This positive feedback event is referred to as the luteal surge.

Menstruation follows ovulation. Gastrulation is a phase of development during which the primary germ layers are generated in an embryo, and is not related to the female cycle.

There are several stages of embryonic development. The first stage is the zygote, which is simply a single cell formed after the sperm fuses with the egg. The cell then begins to divide, creating more cells without actually expanding in size. This process is called cleavage and the embryo is now call a morula. Eventually, the cells orient such that they form a ball with a hollow center and begin to expand in total size. This stage is known as the blastula or blastocyst stage. During this stage, the embryo will enter the uterus and implant into the uterine wall. As the cells continue to divide and orient, the blastocyst develops an inner cell mass, which will be become the new organism. The cells in this area begin to differentiate into the different germ layers through a process known as gastrulation; the resulting embryo is known as a gastrula.

Following gastrulation, the three primary germ layers are formed. They are the ectoderm, the mesoderm, and the endoderm. The ectoderm develops into the skin and the nervous system. The mesoderm develops into the bones and muscle. The endoderm develops into the lining of the digestive tract and most internal organs.

Spermatozoa formation is accomplished in the seminiferous tubules in the testes. Once created, the spermatozoa are taken to the epididymis for storage and maturation. During ejaculation, the sperm is expelled through the vas deferens then through the urethra and out of the penis.

The germ cells (eggs/oocytes and sperm) contain only one copy of each chromosome. This reduction in the amount of DNA occurs through meiosis. Most cells in the body contain two copies of each chromosome and are considered diploid. Since they only contain ne copy of each chromosome, germ cells are considered haploid.

Neurons and lymphocytes (white blood cells) contain two copies of each chromosome; they are diploid. Erythrocytes (red blood cells) do not have nuclei, and do not contain any genetic material.

Ovulation, or the release of the egg from its follicle, is initiated by a temporary spike in estradiol (estrogen) levels. This positive feedback event is referred to as the luteal surge.

Menstruation follows ovulation. Gastrulation is a phase of development during which the primary germ layers are generated in an embryo, and is not related to the female cycle.

There are several stages of embryonic development. The first stage is the zygote, which is simply a single cell formed after the sperm fuses with the egg. The cell then begins to divide, creating more cells without actually expanding in size. This process is called cleavage and the embryo is now call a morula. Eventually, the cells orient such that they form a ball with a hollow center and begin to expand in total size. This stage is known as the blastula or blastocyst stage. During this stage, the embryo will enter the uterus and implant into the uterine wall. As the cells continue to divide and orient, the blastocyst develops an inner cell mass, which will be become the new organism. The cells in this area begin to differentiate into the different germ layers through a process known as gastrulation; the resulting embryo is known as a gastrula.

Following gastrulation, the three primary germ layers are formed. They are the ectoderm, the mesoderm, and the endoderm. The ectoderm develops into the skin and the nervous system. The mesoderm develops into the bones and muscle. The endoderm develops into the lining of the digestive tract and most internal organs.

Spermatozoa formation is accomplished in the seminiferous tubules in the testes. Once created, the spermatozoa are taken to the epididymis for storage and maturation. During ejaculation, the sperm is expelled through the vas deferens then through the urethra and out of the penis.