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10

Peach, apricot, plum, pear, apple, cherry trees are plants of the same family, Rosaceae, so they are closely related. They share many more aspects than the five petals. In fact, other plants in this family, and even many other dicots have five petal, simply because their share a common ancestry.


7

The vascular system is different in monocots and dicots. In dicots the vascular tissues are arranged in concentric circles; one of these rings is meristematic cells (undifferentiated cells that can differentiate into any cell type). This ring of meristem tissue is called the vascular cambium and is where secondary growth occurs - xylem grows inwards and ...


7

The seedless watermelons, like bananas, are a crop that are specifically bred to be trisomic (three copies of a chromosome). The consequence is the seeds are non-viable.


6

The sporophtye is the diploid stage in the life cycle. In comparison, with humans, you and I would be sporophytes. The Gametophyte is the haploid stage in the life cycle. In comparison, with humans, spermatozoids and ovules are gametophytes. Independence Note for what follows: "independent" can be understood in terms of "ability to survive". Being ...


6

Yes it is possible, and as far as I can see, there should not be any plant which would be impossible to grow in a such an environment, just more or less difficult, although this is just my speculation. I have myself grown tomatoes from only a liquid solution of minerals and nutrients, but you have to change the solution from time to time to prevent ...


6

Glucose, fructose and galactose are the three dietary monosaccharides. Glucose and Fructose are simple monosaccharides found in plants. A monosaccharide is the basic unit of carbohydrate and the simplest form of sugar, glucose are aldose and Fructose are ketose. If the carbonyl is at position 1 (that is, n or m is zero), the molecule begins with a ...


5

PART 1 : Phototropism The movement of plant shoot towards light is called phototropism. This process is mainly stimulated by the blue light. The photoreceptor involved is called Phot1 (Phototropin 1) or JK244. Auxins such as IAA (indole acetic acid) are plant hormones, expressed highly in meristem, which cause shoot growth. On illumination this ...


5

The three main cues for flower opening/closing used by plants are temperature, light and humidity (van Doorn & van Meteren 2003, freely available pdf), with the first two being most common. Plants with daily opening and closing of flowers can be divided into nocturnal (open at night) and diurnal (open at day). There exists several different mechanisms ...


5

The roots do actually continue to hold soil without being alie. The stabilizing properties are structural in nature. You begin to lose those though as the roots decompose, and the important roots against erosion, millions of fine root hairs, will go first. But leaving the roots in on a dead tree will help for a bit, but isn't a long term solution.


5

Quantitative descriptions of leaf shape used as diagnostics are hard to come by. There are numerous qualitative descriptions (lyrate, cordate, acicular, etc.), and I think this fits within the example you give that "the laminar shape for this species is mainly ovate." But actual quantitative ranges as you mention (e.g., that the L:W ratio of Acer lies within ...


5

No, its not xylem. Bamboo is a grass, and the stem (culm) of many grasses are hollow in the middle (see e.g. Grass Structures from Oregon state for some more info). The exact reason for why Bamboo have hollow stems is most likely due to evolutionary contingencies. However, from a mechanical stability point of view, a hollow stem is much more rigid and ...


5

"Teleology is like a mistress to a biologist: he cannot live without her but he's unwilling to be seen with her in public." - J.B.S. Haldane (1892 - 1964) I can't tell you why Lapidaria margaretae looks like 'stones'. But I can deduce something from the way this plant looks. First and foremost, I can say this plant probably evolved in an arid region, ...


5

I think that the most important point has been given by CactusWoman, when (s)he says "Just because you cannot forsee a use for more "bulgy" spikes doesn't mean there isn't a use for them." In addition to that, I would like to say that several plants evolved traits that were beneficial at a time where other herbivores existed and that are now useless. Those ...


5

One thing to remember when you uproot a plant is that some of the smallest structures break off most readily. What you will usually see after uprooting the plant are the largest parts of the root structure, but there are often smaller parts which have broken off. Root structure is highly variable, but the general idea is that one or more primary trunk-like ...


4

First, allow me to provide the link to an old paper that deals with development in Ananas comosus, it should be freely available and answer this question in more detail: http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.1936.tb06884.x/pdf Now, to briefly explain the observation that a mature plant will grow from the region where the leaves of the ...


4

Looking through some papers it is not clear to me that botanists actually know why this should be the case, and I am sure that you are more qualified than me to comment on this Richard! However, there's some discussion of this in Zhang et al. (2012). These authors argue that the "exudate from curcubits is copious" because of physiological adaptations due to ...


4

Just because you cannot forsee a use for more "bulgy" spikes doesn't mean there isn't a use for them. Furthermore, natural selection isn't about producing perfect organisms, it's about selecting for traits that are "good enough". There is also more to evolution than natural selection. The phenomenon of genetic drift can cause a neutral or slightly ...


3

There are no roses (that is, flowers of genus Rosa species) that naturally express a "true" blue color. Through cross-breeding, there are lilac-mauve rose horticultural varieties ("Blue Nile","Blue Moon","Lady X", etc.), and through genetic engineering (actually inserting delphinidin-producing genes) there are mauve-lavender varieties ("Applause"). The ...


3

I presume what the author is trying to convey is that as a seed ages, it enters a quiescent phase as a result of natural desiccation. Without more context, I'd guess that the quote you've provided here is referring to secondary dormancy, which is a response to unfavorable germination conditions. By definition, secondary dormancy occurs after the seed is ...


3

Sometimes, the morphology and the topology of the flower structure is such that the pollen grains falling on certain parts are gravitationally (or hydrostatically) drawn towards the stigma. I remember having read that the waxy streamlined stigma of submerged hydrophytes (Vallisneria, Hydrilla) creates mini vortices around it during steady water flow. These ...


3

Members of the Cucurbitaceae family (squash, pumpkin, cucumber, melon etc.) are unique* in that they possess two distinct phloems, see figure below. The fascicular phloem (FP) is the main transport conduit, and more closely resembles the phloems of other plant families. Its role is to transport photosynthates and other nutrients (Turgeon & Oparka, ...


3

From Whittle and Johnston (2006): Specifically, human epidemiological data and/or nucleotide substitution rates of selectively neutral DNA (which equals the mutation rate, Kimura, 1983; Miyata et al., 1987) have shown that more mutations occur in the male than in the female germ line for numerous animal taxa (e.g. humans, mice, chickens, and sheep) and ...


3

The radius of tree is not a good measure of the tree age, the most efficient technique to know the age of a tree is with dendrochronological methods, this is the less invasive technique. However, knowing very well the dynamics of growth of each species you can infer the age, check out this study: Jan Lukaszkiewicz and Marek Kosmala. 2008. Determining the ...


3

First of all, you assumption seems to be incorrect. Plants in same part of the world can twine in opposite directions. Little seems to be known exactly. Gravity has nothing to do with plant's chirality (or "handedness") or spiraling: How plants do this is still unknown. Darwin proposed that it was "autonomously induced." This came to be known as the ...


3

I think your vegetable is a leek, or a closely related allium. If this is the case, you are seeing its flowerbud. Congratulations, it will become quite pretty in some days, I know people who use leeks as decoration plants instead of vegetables.


2

Your statement is partially correct, but not entirely. As an animal embryo, the seed, still closed, is already formed, with the distinction between root, stem and leaves. Tiny but already there are. All the rest of the seed (in this case two cotyledons) is a kind of food dough, and serves as a food reserve for the seedling, until the time of rooting and ...


2

This is the sort of question that should be considered from more than one perspective. Since this is speculation, take it as a given that there is a lot of 'what if' here. I doubt most animals and plants can do entirely without bacteria - as you say most of the essential nutrients come from bacteria, who fix nitrogen. If only plants were left on earth, ...


2

Artificial propagation is (generally) human-directed, while asexual/vegetative reproduction is a natural process. Take a look at the wikipedia article on vegetative reproduction for more information on how and why artificial propagation is sometimes preferred to vegetative reproduction.


2

From Basconsuelo et al 2002: "The zone of the plant axis where the arrangement of vascular systems changes from root- to stem-structure is often called “transition region”" (see also the refs they cite). The idea behind it is that the organization of the vascular tissues is radically different in the root in comparison to the stem, such that the switch ...



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