userfiles/153/my files/29_lecture_presentation?id=3264
... Vascular plants have two types of vascular tissue: xylem and phloem Xylem conducts most of the water and minerals and includes tube-shaped cells called tracheids Water-conducting cells are strengthened by lignin and ...
... Vascular plants have two types of vascular tissue: xylem and phloem Xylem conducts most of the water and minerals and includes tube-shaped cells called tracheids Water-conducting cells are strengthened by lignin and ...
Carbohydrate-based interactions on the route of a spermatozoon to
... and proceed towards the site of fertilization in tightly controlled numbers (Hunter, 1996 and references therein). With the changing conditions in the oviduct at the time of ovulation, spermatozoa may shed their protein coat sequentially, thus creating new surface structures which could allow sperma ...
... and proceed towards the site of fertilization in tightly controlled numbers (Hunter, 1996 and references therein). With the changing conditions in the oviduct at the time of ovulation, spermatozoa may shed their protein coat sequentially, thus creating new surface structures which could allow sperma ...
19 REPRODUCTION IN PLANTS MODULE - 3
... (c) Sexual reproduction involves fusion of male and female reproductive cells (gametes) which are haploid and are produced by male and female reproductive organs. This fusion is known as fertilization and results in the production of a zygote (diploid). Further development of zygote gives rise to a ...
... (c) Sexual reproduction involves fusion of male and female reproductive cells (gametes) which are haploid and are produced by male and female reproductive organs. This fusion is known as fertilization and results in the production of a zygote (diploid). Further development of zygote gives rise to a ...
1 m
... • Water-conducting cells are strengthened by lignin and provide structural support • Phloem consists of living cells and distributes sugars, amino acids, and other organic products • Vascular tissue allowed for increased height, which provided an evolutionary advantage © 2011 Pearson Education, Inc. ...
... • Water-conducting cells are strengthened by lignin and provide structural support • Phloem consists of living cells and distributes sugars, amino acids, and other organic products • Vascular tissue allowed for increased height, which provided an evolutionary advantage © 2011 Pearson Education, Inc. ...
evolution and diversity of woody and seed plants
... 2. Endospory. Endospory is the complete development of, in this case, the female gametophyte within the original spore wall (Figure 5.6). The ancestral condition, in which the spore germinates and grows as an external gameto phyte, is called exospory. The evolution of endosporic female gametophytes ...
... 2. Endospory. Endospory is the complete development of, in this case, the female gametophyte within the original spore wall (Figure 5.6). The ancestral condition, in which the spore germinates and grows as an external gameto phyte, is called exospory. The evolution of endosporic female gametophytes ...
The Plant Kingdom: Seedless Plants
... seeds borne exposed (unprotected) on a stem or in a cone. Plants with seeds as their primary means of reproduction and dispersal first appeared about 359 mya, at the end of the Devonian period. These early seed plants diversified into many varied species of gymnosperms. The most recent plant group to ...
... seeds borne exposed (unprotected) on a stem or in a cone. Plants with seeds as their primary means of reproduction and dispersal first appeared about 359 mya, at the end of the Devonian period. These early seed plants diversified into many varied species of gymnosperms. The most recent plant group to ...
- Journal of Clinical Investigation
... which is composed of a glycosylaminoglycan matrix and cumulus cells. They then bind to the zona pellucida that surrounds the mammalian egg (1, 2). The mouse and human zonae pellucidae are composed of three major glycoproteins, ZP1, ZP2, and ZP3. Solubilized zonae pellucidae from unfertilized mouse e ...
... which is composed of a glycosylaminoglycan matrix and cumulus cells. They then bind to the zona pellucida that surrounds the mammalian egg (1, 2). The mouse and human zonae pellucidae are composed of three major glycoproteins, ZP1, ZP2, and ZP3. Solubilized zonae pellucidae from unfertilized mouse e ...
Spontaneous male death and monogyny in the dark fishing spider
... monogyny is likely to evolve in taxa with first-male sperm precedence [5]. While sperm precedence patterns are not known for many animal taxa, particular traits and behaviour are often coincident with first-male sperm precedence, for example, early male maturation and precopulatory mate guarding [22 ...
... monogyny is likely to evolve in taxa with first-male sperm precedence [5]. While sperm precedence patterns are not known for many animal taxa, particular traits and behaviour are often coincident with first-male sperm precedence, for example, early male maturation and precopulatory mate guarding [22 ...
video slide
... 3 A pollen grain becomes a mature male gametophyte when its generative nucleus divides and forms two sperm. This usually occurs after a pollen grain lands on the stigma of a carpel and the pollen tube begins to grow. (See ...
... 3 A pollen grain becomes a mature male gametophyte when its generative nucleus divides and forms two sperm. This usually occurs after a pollen grain lands on the stigma of a carpel and the pollen tube begins to grow. (See ...
The Program of and Mechanisms of Fertilization in the Echinoderm
... mechanism could result from actin-like filaments in the sperm or egg interacting with cytoplasmic or cortical myosin of the egg or sperm, leading to contraction and resultant sperm entry (Model B, Fig. 4). As a third mechanism, entry could occur via movement of the plasma membrane itself. Recent wor ...
... mechanism could result from actin-like filaments in the sperm or egg interacting with cytoplasmic or cortical myosin of the egg or sperm, leading to contraction and resultant sperm entry (Model B, Fig. 4). As a third mechanism, entry could occur via movement of the plasma membrane itself. Recent wor ...
video slide - Course
... – Pollination is the transfer of pollen from an anther to a stigma – If pollination is successful, a pollen grain produces a structure called a pollen tube, which grows down into the ovary and discharges sperm near the embryo sac ...
... – Pollination is the transfer of pollen from an anther to a stigma – If pollination is successful, a pollen grain produces a structure called a pollen tube, which grows down into the ovary and discharges sperm near the embryo sac ...
video slide - Course-Not
... • A cuticle and secondary compounds evolved in many plant species. Symbiotic associations between fungi and the first land plants may have helped plants without true roots to obtain nutrients. • Four key derived traits of plants are absent in the green algae charophytes: – Alternation of generations ...
... • A cuticle and secondary compounds evolved in many plant species. Symbiotic associations between fungi and the first land plants may have helped plants without true roots to obtain nutrients. • Four key derived traits of plants are absent in the green algae charophytes: – Alternation of generations ...
Acquired characteristics
... The major groups of plants are shown. Note that adaptive transitions evolved at different points: water to land from ancestral green algae (not shown); nonvascular to vascular; seedless to seed; flowers. ...
... The major groups of plants are shown. Note that adaptive transitions evolved at different points: water to land from ancestral green algae (not shown); nonvascular to vascular; seedless to seed; flowers. ...
Full text in pdf format
... (17 × 17 × 6 cm, length × width × depth) filled with filtered seawater was also provided for drinking. The light:dark regime matched the natural local conditions with natural light coming through a transparent roof. Mating trials and methods for sperm counts. Female pleonal expansion is strongly cor ...
... (17 × 17 × 6 cm, length × width × depth) filled with filtered seawater was also provided for drinking. The light:dark regime matched the natural local conditions with natural light coming through a transparent roof. Mating trials and methods for sperm counts. Female pleonal expansion is strongly cor ...
17. Plants, Fungi, and the Colonization of Land
... 17.6 Ferns, like most plants, have a dominant sporophyte 1. Small haploid gametophyte produces sperm that swim to the egg 2. Zygote remains on the gametophyte 3. Zygote undergoes mitosis and develops into independent diploid sporophyte 4. Meiosis in sporangia produces haploid spores 5. Spores are r ...
... 17.6 Ferns, like most plants, have a dominant sporophyte 1. Small haploid gametophyte produces sperm that swim to the egg 2. Zygote remains on the gametophyte 3. Zygote undergoes mitosis and develops into independent diploid sporophyte 4. Meiosis in sporangia produces haploid spores 5. Spores are r ...
Development ppt
... • Capacitation: the process by which the acrosomal region of a sperm becomes weakened • This allows hydrolytic enzymes to be released from the sperm near the oocyte ...
... • Capacitation: the process by which the acrosomal region of a sperm becomes weakened • This allows hydrolytic enzymes to be released from the sperm near the oocyte ...
video slide - ScienceToGo
... Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings ...
... Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings ...
Lab-8, Cycads
... able to locate the outer layers of the integuments which are fleshy, an inner portion of the integument which is hard or stony, and a large, relatively light colored megagametophyte. In the micropylar region of the megagametophyte you may see several large hollow areas; these are the archegonia whos ...
... able to locate the outer layers of the integuments which are fleshy, an inner portion of the integument which is hard or stony, and a large, relatively light colored megagametophyte. In the micropylar region of the megagametophyte you may see several large hollow areas; these are the archegonia whos ...
Chapter 38
... – Pollination is the transfer of pollen from an anther to a stigma – If pollination is successful, a pollen grain produces a structure called a pollen tube, which grows down into the ovary and discharges sperm near the embryo sac ...
... – Pollination is the transfer of pollen from an anther to a stigma – If pollination is successful, a pollen grain produces a structure called a pollen tube, which grows down into the ovary and discharges sperm near the embryo sac ...
Reproduction
... in moist soil which give rise to adventitious roots, and grow into new plants. iii) Layering: Layering is the development of roots on a stem while it is still attached to the parent plant. The stem or the branch that develops adventitious roots while still attached to the parent plant is called a la ...
... in moist soil which give rise to adventitious roots, and grow into new plants. iii) Layering: Layering is the development of roots on a stem while it is still attached to the parent plant. The stem or the branch that develops adventitious roots while still attached to the parent plant is called a la ...
Document
... motile for a long time in the mucus might be an evolutionary adaptation by the females to guarantee complete fertilization. Additionally, by keeping sperm alive for a long period of time females may provoke sperm competition. It pays for sneaker males to engage in fertilization even if there is a co ...
... motile for a long time in the mucus might be an evolutionary adaptation by the females to guarantee complete fertilization. Additionally, by keeping sperm alive for a long period of time females may provoke sperm competition. It pays for sneaker males to engage in fertilization even if there is a co ...
Plant Diversity I: Non-vascular vs. vascular plants
... one major way to distinguish groups of plants is to classify them as: vascular & nonvascular – vascular tissue – extensive system formed by cells joined into tubes – conduct water and nutrients – those without these tubes – non-vascular plants ...
... one major way to distinguish groups of plants is to classify them as: vascular & nonvascular – vascular tissue – extensive system formed by cells joined into tubes – conduct water and nutrients – those without these tubes – non-vascular plants ...
Fertilisation
Fertilisation (also known as conception, fecundation and syngamy) is the fusion of gametes to initiate the development of a new individual organism. In animals, the process involves the fusion of an ovum with a sperm, which first creates a zygote and then leads to the development of an embryo. Depending on the animal species, the process can occur within the body of the female in internal fertilisation, or outside (external fertilisation). The cycle of fertilisation and development of new individuals is called sexual reproduction.