- Plasmogamy involves the fusion of cytoplasm between two parent fungi without nuclear fusion, forming a secondary mycelium with one nucleus from each parent. Karyogamy involves nuclear fusion and produces genetic variation through somatic diploids.
- Animal cells lack cell walls and have structural proteins like collagen to hold their multicellular bodies together. Most animals reproduce sexually through fertilization and have a diploid stage dominating their life cycle.
- Animal development proceeds through cleavage, formation of a blastula and gastrula, and then organogenesis from the three germ layers. Their multicellular origin can be traced to colonial protistan ancestors.
A second type of cell division called meiosis takes place in multicellular eukaryotes. This is a reduction division in which the daughter cells receive exactly half the number of chromosomes of the mother cells.
Meiosis occurs in the production of gametes—the sperm of the males and the eggs of the females. When a sperm fertilizes an egg, a zygote is produced with the appropriate number of chromosomes for the species—in humans (and potatoes) the zygote and the somatic (body) cells produced from it have 46 chromosomes. This is the diploid (2n) number of chromosomes, half of which have come from the sperm nucleus, half from the egg. The sperm and egg are haploid ( n); they carry half the number of chromosomes of the body cells (in humans, 23 in each sperm and egg). Meiosis thus makes it possible to maintain a constant number of chromosomes in a species that reproduces sexually by halving the number of chromosomes in the reproductive cells. Meiosis uses many of the same mechanisms as mitosis and is assumed to have been derived from mitosis after the latter procedures were in place in some early organisms millenia ago.
Figure 1 shows the stages of mitosis, and Figure 2 shows the stages of meiosis. Note that the names for the stages are the same as those of mitosis, with the addition of a numeral to designate either the first or the second divisional stage. Both divisions are part of meiosis; not until the final four daughter cells are produced is the process complete.
Synapsis in Prophase I is a decisive interval in determining the inheritance of the daughter cells. At this time, genetic recombination can occur; that is, daughter cells may receive combined traits of their two parents rather than simply the trait from one or the other. This is possible because the phenomenon called crossing over often occurs when the chromatids lie together—segments containing similar alleles break apart and rejoin to the corresponding segment of the opposite chromatid, thus mixing the traits from individual parents.
XX-XY sex determination is one of the chromosomal sex determination where sperm determines the sex of the progeny. This type of sex determination is seen in plants also. MELANDRIUM ALBUM is one.
A second type of cell division called meiosis takes place in multicellular eukaryotes. This is a reduction division in which the daughter cells receive exactly half the number of chromosomes of the mother cells.
Meiosis occurs in the production of gametes—the sperm of the males and the eggs of the females. When a sperm fertilizes an egg, a zygote is produced with the appropriate number of chromosomes for the species—in humans (and potatoes) the zygote and the somatic (body) cells produced from it have 46 chromosomes. This is the diploid (2n) number of chromosomes, half of which have come from the sperm nucleus, half from the egg. The sperm and egg are haploid ( n); they carry half the number of chromosomes of the body cells (in humans, 23 in each sperm and egg). Meiosis thus makes it possible to maintain a constant number of chromosomes in a species that reproduces sexually by halving the number of chromosomes in the reproductive cells. Meiosis uses many of the same mechanisms as mitosis and is assumed to have been derived from mitosis after the latter procedures were in place in some early organisms millenia ago.
Figure 1 shows the stages of mitosis, and Figure 2 shows the stages of meiosis. Note that the names for the stages are the same as those of mitosis, with the addition of a numeral to designate either the first or the second divisional stage. Both divisions are part of meiosis; not until the final four daughter cells are produced is the process complete.
Synapsis in Prophase I is a decisive interval in determining the inheritance of the daughter cells. At this time, genetic recombination can occur; that is, daughter cells may receive combined traits of their two parents rather than simply the trait from one or the other. This is possible because the phenomenon called crossing over often occurs when the chromatids lie together—segments containing similar alleles break apart and rejoin to the corresponding segment of the opposite chromatid, thus mixing the traits from individual parents.
XX-XY sex determination is one of the chromosomal sex determination where sperm determines the sex of the progeny. This type of sex determination is seen in plants also. MELANDRIUM ALBUM is one.
Sex determination is important to distinguish an organism as male, female and hermaphrodite. XX-XO sex determination is one type of determination which is found in plants and insects
Reference
Moeller, Karla T., "Temperature-Dependent Sex Determination in Reptiles". Embryo Project Encyclopedia (2013-02-01). ISSN: 1940-5030
Morjan, Carrie L. 2003. “How Rapidly Can Maternal Behavior Affecting Primary Sex Ratio Evolve in a Reptile with Environmental Sex Determination ?”
Shine, Richard. 1999. “Why Is Sex Determined by Nest Temperature in Many Reptiles?” 14(5): 186–89.
Wapstra, Erik et al. 2006. “Maternal Basking Behavior Determines Offspring Sex in a Viviparous Reptile.” : 230–32.
Integrated assessment of human and animal wasteILRI
Humans and animals produce an important quantity of waste that affects health and environment. Waste must be seen as resource and resources recovered from wastes and reused, while considering health safety and effectiveness. We developed a conceptual framework for improving health and environmental sanitation using an approach combining health, ecological, socio-economic assessments.
Sex determination is important to distinguish an organism as male, female and hermaphrodite. XX-XO sex determination is one type of determination which is found in plants and insects
Reference
Moeller, Karla T., "Temperature-Dependent Sex Determination in Reptiles". Embryo Project Encyclopedia (2013-02-01). ISSN: 1940-5030
Morjan, Carrie L. 2003. “How Rapidly Can Maternal Behavior Affecting Primary Sex Ratio Evolve in a Reptile with Environmental Sex Determination ?”
Shine, Richard. 1999. “Why Is Sex Determined by Nest Temperature in Many Reptiles?” 14(5): 186–89.
Wapstra, Erik et al. 2006. “Maternal Basking Behavior Determines Offspring Sex in a Viviparous Reptile.” : 230–32.
Integrated assessment of human and animal wasteILRI
Humans and animals produce an important quantity of waste that affects health and environment. Waste must be seen as resource and resources recovered from wastes and reused, while considering health safety and effectiveness. We developed a conceptual framework for improving health and environmental sanitation using an approach combining health, ecological, socio-economic assessments.
The animal health care market in the world has grown remarkably over the past few years due to the growth in the emerging markets such as China, India, Indonesia, Thailand, Malaysia and Taiwan followed by US and Europe. The animal health industry’s SWOT analysis provides animal health solutions to society depends on its in-depth knowledge of both cutting-edge technologies and classical veterinary science to innovate and keep up with the animal and human health challenges of new and emerging diseases. The main finding of this project indicates India is one of the important markets and can be seen as a key growth area in global animal health care industry.
- The Indian animal healthcare industry is responsible for maintaining the health and productivity of the over 640 million livestock and 2 billion poultry in India and ensuring the wholesomeness and abundance of the food they produce. Apart from, the industry must also cater to the health and well being of companion animals. Despite this, the global animal healthcare market is 50 times larger than the Indian animal healthcare combined market for all nonhuman species. In spite of this India’s largest milk and 3rd largest meat producer, and blessed with largest cattle population 20% of the world population, and largest buffalo more than 50% of the world. Veterinary Pharmaceutical is yet not considered as big industry as compared to Human Pharmaceutical. The reality is that the global animal health market is very complex, operating under stringent and increasingly strict regulations similar to those for human health, yet the market opportunities are considerably smaller. In an increasingly risky environment for new product development and innovation, the difference between success and failure in the future usually lies in successfully identifying the next growth segment, developing the right product candidates and being the first to market. The situation in developing countries like India is varied and economic and institutional framework of the live stock is often quite different in several respects to that encounter in developed world.
A challenging aspect of the overall market is within the animal food industry as consumers continue to express concern about the conditions under which their daily food is produced. Indian consumers are becoming more health conscious, willing to pay any amount and demanding healthy and balanced diets. By implementing a feeding plan that provides vitamins and supplements, consumers enjoy additional nutritional benefits. Additionally, healthy feeding results in minimized impact on the environment.
Giving overview of human embryonic development including spermatogenesis, oogenesis, fertilization, gastrulation, cleavage, extraembryonic layers and pregnancy
Here is a sampling of architectural works from my portfolio. These projects were designed when I was a student at the Universities of Colorado and Minnesota. Take a look and enjoy.
This slide shows the information about gameophyte.
there are two type of gametophyte
1) male gameetophyte
2)female gametophyte
we only discussed about the female gametophyte. it has megagametogenesis and different kind of embryo secs and their discription are also their in the slide.
defined as a biological process in
which an organism gives rise to
young ones (offspring) similar to
itself.
Asexual reproduction:
Offsprings produced by single
parents.
Without involvement of gamete
formation
Offsprings are genetically
identical to their parentsCell division as a method of asexual
reproduction as in Protista and monera.
Binary fission e.g. Amoeba, Paramecium.
Budding: e.g. yeast.
Asexual reproductive structures:
Zoospores: aquatic fungi, Chlamydomonas.
Conidia: Penicillium.
Bud: Hydra
Gemmules: sponges.
Vegetative propagation units in plant:
(Vegetative propagules)
Runner, rhizome, sucker, tuber, offset, bulb.
![Plasmogamy vs karyogamy ,[object Object],[object Object]](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)