Chapter 38 Plant reproduction and Development
Sexual Reproduction
1. In general terms, explain how the basic plant life cycle with alternation of generations is modified in angiosperms.
The basic plant life cycle with alternation of generations is modified in angiosperms by the change of haploid (n) and diploid (2n) generations, which take turns making each other. 2. List four floral parts in order from outside to inside a flower.
Sepals
Petals
Stamen
Carpels
3. From a diagram of an idealized flower, correctly label the following structures and describe the function of each structure: a. sepals- Sepals are in charge of protecting the flower’s bud before it blooms. It has the qualities of a leave and is usually in
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This has many advantages, such as the fact that double fertilization guarantees that the endosperm will develop only in ovules where the egg has been fertilized. It also avoids angiosperms from wasting nutrients. 13. Explain how fertilization in animals is similar to that in plants.
Fertilization in animals is similar to that in plants because its first cellcell change occurs after gamete fusion rises in the cytoplasmic Ca2+ levels as it does in animal gamete fusion. Also, the plants make a block to polyspermy, which is the fertilization of an egg by more than one sperm cell, as do the animal’s cell’s eggs. 14. Describe the fate of the ovule and ovary after double fertilization. Note where major nutrients are stored as the embryo develops.
After double fertilization, the ovule matures into a seed, and the ovary matures into a fruit encircling the seed. As the embryo grows the seed stores proteins, oils, and starch. 15. Describe the development and function of the endosperm. Distinguish between liquid endosperm and solid endosperm.
After embryo development, endosperm is growth to store nutrients. This happens after double fertilization, when the triploid nucleus of the ovule’s central cell divides. This causes the formation of a milky multinucleate “supercell”. This becomes multicellular after cytokinesis. Finally, when the cell walls are completed, the endosperm becomes solid. 16. Describe the development of
In a plant’s life cycle, there are a few key details such as germination, growth, egg or sperm production, pollination, seed production and dispersal, and finally death. In the germination phase the seed sprouts after a certain exposure to light, temperature, and moisture (Pima Community College). In the growth stage the sprout turns into a mature plant, this is followed by the production of an egg or sperm and then pollinated by other pollen transferred by the wind or an animal. Next is the seed production when the embryo and endosperm get a seed coat to form a new seed, the dispersal of the seed occurs it is transferred from the parent by interaction with an animal. Finally death, it’s pretty obvious, death is when the plant dies.
At some point within the sporophyte plant a few of the cells will divide by meiosis and they will be haploid cells, having a single set of chromosomes. These cells are called spores and will become independent plants. A multicellular plant develops, and all its cells will have a single set of chromosomes, this happens when the haploid spores germinate and grow by mitosis. This stage of the life cycle is called gametophyte generation. The gametophyte plant matures and produces specialized cells, they will form gametes,
Round seeds (R) are dominant to wrinkled seeds (r), and yellow seeds (Y) are dominant
Exercise 3A is a study of mitosis. You will simulate the stages of mitosis by using chromosome models.You will use prepared slides of onion root tips to study plant mitosis and to calculate the relative duration of the phases of mitosis in the meristem of root tissue. Prepared slides of the whitefish blastula will be used to study mitosis in animal cells and to compare animal mitosis and plant mitosis.
4. What is it called when an egg from the female is withdrawn and fertilized with sperm in a laboratory for 2 to 3 days with subsequent implantation into the uterus?
Asexual Propagation is the process of using plant materials such as the stems, leaves, and roots to multiply the number of plants. These plants eventually grow to be a brand new plant that is genetically identical to the parent plant it came from. In several types of plants, asexual propagation is the fastest means of new plant growth. Asexual propagation is also a good way to maintain a plant species because they are genetically identical. In this process, adventitious roots are seen in the growing cycle. Adventitious roots are those that grow form parts of the plant that they normally would not grow from. The cuttings must do
The temperature is at 37˚ C and the gas mixture consists of 90% Ν₂, 5% Ο₂ and 5% CO₂. With these conditions the desired level of pH in the medium surrounding the oocytes is ensured. After incubation of two hours, the oocytes are evaluated microscopically regarding their maturation state. To investigate whether the oocytes collected are mature, the embryologist will observe one by one for the presence of the polar body. Mature oocytes are collected again and placed in the incubator until the time of
Now, imagine that instead of developing separately, these fertilized eggs actually fuse. Then only one baby would develop.
2. Imagine oocytes as pallets of ice creams and the uterus as a freezer. Ice creams need a certain environment to remain solid. Unfortunately, our industrial
The generation rate and success of new asexual lineages will be influenced by the proximate mechanisms underlying transitions to asexuality. This article also explains how the asexual reproduction in animal and plants can be both a confused mix of term. It is known that in plants, asexual reproduction can occur either through budding and vegetative growth like for example the shoot and the runners. This article explain how the different terms people used in plants and animals refer to the same concept. An example is that in plants and animals, production of offspring via syngamy of meiotic produced gametes. These term are known in both plants and animals as sexual
After the rate of mitotic division has slowed down, the blastomeres undergo dramatic movements wherein they change their positions relative to one another. This series of extensive cell rearrangements is called gastrulation, and the embryo is said to be in the gastrula stage. As a result of gastrulation, the embryo contains three germ layers: the ectoderm, the endoderm, and the mesoderm.
The process of embryo transfer requires a dose of Follicle Stimulating Hormone (FSH) twice a day for four days towards the end of her estrus cycle to force them to super ovulate, or release more than one egg at a time. On average a donor cow will release five to six eggs at a time but other donors will release more than twenty. Once the donor cow comes into heat, the peak time for insemination to occur, a technician will artificially inseminate the cow with high quality semen multiple times due the increased number of eggs being released by the donor cow. After seven days the embryos will be flushed out and graded. (Embryo) The other method, In Vitro Fertilization, does not fertilize eggs inside of the donor cow, they are flushed out unfertilized and placed into petri dishes, where they are matured for 24 hours before insemination. Eggs are mixed with semen and then incubated for seven days, after which they are considered embryos and are ready for transfer to the recipient cow. (In
In Angiosperms, polyploidization is a common process that leads to the evolution and speciation of species (2 to 4% of speciation cases are related to chromosome doubling (Otto and Whitton, 2000)). Polyploidy corresponds to the process in which a cell has more than two pairs of the same chromosome. This process leads to profound genetic variation and consequently, phenology, reproduction, fitness, etc also change creating an opportunity to the species improvement or even a new species/cytotype formation (___)
The totipotent cells then turn into a blastocyst by many types of cell division, which forms a lot of cells in side.
Sex allocation refers to the amount of parental resources assigned to male versus female offspring in a sexually reproducing species {Charnov:1982wg, Brunet:1992fg,West:2010ws} and the extent of this allocation in the organism 's fitness. In angiosperms, the flowers are the reproductive organs, but opposite to most animals, the presence of male and female organs varies among species resulting in a large diversity of breeding systems. Those breeding systems are defined on the basis of the presence and fertility of male or female reproductive organs either in the same flower or in the same individual. Then, breeding systems can be categorized as monomorphic, when individuals have both male and female functions (hermaphroditism and