Tag Info

Hot answers tagged

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

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 ...


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

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 ...


4

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.


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

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

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. Note for what follows: "independent" can be understood in terms of "ability to survive". Being independent according ...


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, ...


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 ...


2

Researchers at Ghent University have made a discovery that downregulation of the proteins CONSTANS 1 (SOC1) and FRUITFULL (FUL) lead to the development of many perennial traits in annual plants (in the study Arabidopsis thaliana is used) (reference). The CONSTANS gene controls flowering in Arabidopsis thaliana (reference). FRUITFULL (FUL) is an MADS box ...


1

You can see the wikipedia article on meristem. The apical meristem differentiates into floral meristem that gives rise to flowers. From this the cells specifically expressing APETALA3 (AP3), PISTILLATA (PI), AGAMOUS (AG) and SEPALLATA (SEP) would give rise to the stamen [ref]. CRC gene is essential for female development and plants lacking this will not ...


1

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 ...


1

Dr Karl Niklas from the Cornell University has written a book about the effects of factors that influenced the shape of early trees. He created a computer model in which he drew trees in the shape that favored particular characteristics. When Niklas favored plants that could gather light from the sun, they had non-overlapping horizontal branches. When ...


1

Oreotrephes, it all depends on the needs. Reproductive schemas don't exclude shape schemas. There has been, however, a shift to cladistics in classification, which means to give scientific names ONLY to monophyletic groups, i.e. groups that include all the descendants of a single ancestor - and only its descendants. But we still use tree/shrub distinction ...


1

This is a very good question, but I think the reason that it's not being answered is because it is in a sense too broad: different plant groups maintain balances of cleistogamous and chasmogamous flowers, and they modulate that balance through different mechanisms. Many of these mechanisms (genes involved, environmental cues, developmental pathways) may not ...


1

You're not accounting for anything other than "the happy path" here. For instance, not all seeds care about warmth or oxygen, and not very many can last for hundreds or thousands of years, and those that do often require more than transportation to another area to germinate. Otherwise, it sounds fairly accurate.


1

The wikipedia page Alternation of Generations actually has a pretty sophisticated discussion of this issue, and discusses the fact that plants can and do fall at a lot of different places on a gradient of one generation being dominant over another. I think the root of this complexity is that this is an issue of terminology, and is connected to your concept ...


1

Pavement cells should content you: From http://dev.biologists.org/content/131/21/5215.full


1

For qualitative features, you could try essentially any flora. Most of these will have descriptions like this one in Flora of China Acer .... Leaves mostly simple and palmately lobed or at least palmately veined, in a few species pinnately veined and entire or toothed, or pinnately or palmately 3-5-foliolate. The problem with using florae is ...


1

It is hard finding answers to this question, which also interests me a lot. The most satisfying answer I have found is detailed in this paper http://www.ijpam.eu/contents/2012-78-3/6/6.pdf. From the abstract : "This article examines why many flowers are five-petaled through the use of a five-petal model that draws insight from the location of cell clusters ...


1

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 ...



Only top voted, non community-wiki answers of a minimum length are eligible