SCHOOL OF MOLECULAR AND LIFE SCIENCES LESAILANE M 201505020 BOTANY ASSIGNMENT 1 28/JULY/2017 INTRODUCTION Plants have evolved mechanisms to avoid self-pollination which brings about inbreeding, cross pollination is encouraged. It is of crucial importance that not only does a plant grow to its maturity stage, but also that it should produce fertile offspring and ensure that it maintains genetic continuity of the plant population. Plants are immobile organisms, so they need pollinating vectors to help them transfer pollen from the anthers to the stigma of different flowers, in order to ensure cross-pollination. Animal pollinators are of a huge importance in the production of various ﬂowering plants. Interspeciﬁc pollen transfer
They also promote the production of other hormones and in conjunction with cytokinins, they control the growth of stems, roots, and fruits, and convert stems into flowers. Auxins were the first class of growth regulators discovered. They affect cell elongation by altering cell wall plasticity. They stimulate cambium, a subtype of meristem cells, to divide and in stems cause secondary xylem to differentiate. Auxins act to inhibit the growth of buds lower down the stems (apical dominance), and also to promote lateral and adventitious root development and
In different ecosystems, bees play an important role in pollination and the maintenance of natural plant communities. During millions of years, there is a complex interdependence between bees and most of the flowering plants which shows that bees and plant belong together. However, due to the using of agricultural pesticides or the climate changes, many bees loss to “colony collapse disorder” which may bring far-reaching impacts on world’s food supply and biodiversity. Bees are one of the common pollinators in animal pollination. According to David, Kevin and Emily’s (2015) research, it also points out that wild bees can support pollination of multiple plant species owing to the bees’ physique, numbers and behavior of foraging on same plant at one time.
For century’s plants have evolved and developed mechanisms to attract and defend against animals for survival. Plants have evolved two ways to pollinate; either without the involvement of organisms known as abiotic, or with the involvement of organisms known as biotic (Plant pollination). Conifers and grasses are pollinated by wind, whereas many aquatic plants are pollinated by water (plant pollination). For plants that use biotic pollination, insects like moths, bees, butterflies, and beetles as well as animals like birds and bats all help in the plants reproduction (pollinators home page). In order to use the animals or insects to pollinate they need to attract them, this is done is a variety of ways.
Serena Harris Paper on meiosis 2/27/18 Introduction: Meiosis is cell division in a sperm or egg, that moves one part of the chromosome found in the parent cell. The main motive of meiosis is generating off springs through sexual reproduction. The process of meiosis occurs in all living things. And, just like mitosis, meiosis also has multiphase procedures. Ploidy: Meiosis has two divisions meiosis I and meiosis II.
1. Darwin Theory of Evolution helped come up with the conclusion of natural selection and shared ancestry. Meaning that all species arise and develop through inherited variations, increasing the species ability to survive, reproduce, and compete. The primary example for this theory was his findings of the finches on the Galapagos island. He noticed that these finches were similar to other species that were on different islands.
Natural cloning also occurs in mammals, including humans. Twins are produced, when a fertilised egg splits. This split creates multiple embryos with almost the same genetic information. (Information gathered from this year’s Biology textbook) Artificial Cloning: There are three types of artificial cloning, namely gene, reproductive and therapeutic cloning. Gene: this is when a desire gene is located and cloned from DNA extracted from the organism that contains the desired gene.
Pineapples are bred two different ways; seeds and vegetative. Vegetative is used more than seeds because seeds germinate slow and are used more in breeding programs. Pineapples are propagated by vegetation (The Biology). The most common parts of the pineapple used in vegetative propagation are the crowns, slips, and ratoons (GeoChemBio.com). The main pollinator for pineapples is hummingbirds.
One example would be colourful petals on flowering plants. When colourful petals develop in plants it is a sign of sexual maturity and means that the sexual organs of the plant are producing gametes. The colour of the flowers attracts insects that are a vector for the pollen to be transported to other individuals so reproduction can occur. The reason for plants reproducing with other individuals is allows alleles to be spread around the population, this allows for possible resistances to diseases or infections to be passed around the population. Another example of this would be in fruits and vegetables where the colours of the seed-containing vector remain dull until sexual maturity is reached and new, brighter pigments begin to be produced, these bright colours attract animals to ingest the fruit.
Pollination syndrome in large flowered plants Pollination is the transfer of pollen from anther to the stigma on other plants. In this, our focus is on cross pollination where it brings about genetic diversity among these flowers. This can happen with the help of natural pollinators such as birds, bees, mammals, insects, wind and water because plants cannot move from one place to another. These factors play a role in pollination and have a great influence in this process, by making sure that it takes place, while their intention is to gain rather benefit nectar, pollen and some part of the plant. A successful pollination depends on the following factors, pollination effectiveness, pollinator’s visitation to the plants, and their adaptation’s