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13

The more "dangerous" properties of spicy peppers are chiefly due to capsaicin. Sigma-Aldrich sells purified capsaicin, for which they provide safety information, including an MSDS. Most of it is the usual, unsurprising set of warnings about irritation to eyes and the respiratory system. However, there are LD50 numbers: LD50 Oral - rat - male - 161.2 ...


9

Disclaimer: This is not my field of research. First, this is not a complete answer to our question. A nice explanation of the current hypothesis of water transport in trees (Dixon-Joly cohesion-tension theory, originally proposed 1894) can be found at The Amazing Physics of Water in Trees but also in Tyree (1997). The key points are that the stoma (leaf ...


9

Basically, they don't. Ecosystems are pretty much either de facto, delimited by geographical boundaries, or defined by us. For example, an underground lake would be an ecosystem and it is organized in such a way for the simple reason that there is no communication between it and any other system. Most ecosystems however, do communicate. For example, we ...


8

Basically just search "thing you want" and "phylogeny" and you'll find a million results on Google. For you, I might recommend the Botanist in the Kitchen blog, which has a whole page on the subject and has assembled this phylogeny, including many, many others. It's pretty impressive!


8

They are basically conjoined apples which share a common stalk. They are rare but do happen. Here is an article of one discovered in a backyard. conjoined apple discovered in a store (reference) It apparently happens because of bad weather conditions, stress and insect damage. Fused fruits are also found in the case of cherries, watermelons, peaches ...


7

In general for plants, before you start trying to make your own phylogeny, you should try to find an existing phylogeny. Phylogenetics is complex, and a lot of people have already done the hard work. You can start by looking at the Angiosperm Phylogeny to figure out which species are most closely related. To make use of the tree you will usually have to look ...


7

Trees need: Deep roots to get more water and anchor their growth. Strong trunks to support themselves against gravity. A vascular system to move water and nutrients throughout the tree. Small leaves that can be supported high by the trunk to compete for sunlight. Water plants need: Just enough root to anchor its location. No vascular system. Water is ...


7

It's Echinacea. I've linked to one site but if you run an images search with Echinacea as the search term you'll see lots of examples. And here is the WP page. Supplementary Echinacea are members of the Compositae. The flower (the head) in your picture is actually made up of lots of individual smaller flowers (i.e. it is a composite flower). The petals ...


6

It is a Mimosa pudica, a wonderful plant. According to wikipedia you can find it in the following places: Mimosa pudica is native to South America and Central America. It has been introduced to many other regions and is regarded as an invasive species in Tanzania, South Asia and South East Asia and many Pacific Islands. It is regarded as invasive in ...


6

From How Do Pine Cones Open (Nature): The scales of seed-bearing pine cones move in response to changes in relative humidity. The scales gape open when it is dry, releasing the cone's seeds. When it is damp, the scales close up. The cells in a mature cone are dead, so the mechanism is passive: the structure of the scale and the walls of the cells ...


6

This looks pretty much like Buddleja davidii to me. They are available in a range of different colors, see this image from the Wikipedia:


5

The cost would increase; either because pollination services are not provided and the supply is decreased; or because the cost to producers goes up as they must pay for artificial pollination. See the extremely detailed analysis in Winfree et al. edit I imagine what you're actually asking for is a $ figure "per apple". This depends on the location, crop, ...


5

There is absolutely no way to tell to be honest because mulberry trees have the capability of changing sex (reference). From a paper titled "Diversification of mulberry (Morus indica var. S36), a vegetatively propagated tree species", I quote The sex expression of plants appears to be a function of hormonal control; there seems to be evidence that ...


5

Dried grains are very mostly viable means they are in a dormant state until and unless suitable condition are provided. More dried it will be viable for longer. In fact there are seed found in Siberia which are ~32,000 years ans still viable. Courtesy: National Geographic Source: US Emergency Supply: Introduction to Seed Viability


5

Howe and Smallwood (1982) provide a nice review of the many methods of seed dispersal that have evolved in plants. The review is broad but they do have a section on frugivory. They highlight hypotheses developed by McKey, and Howe and Estabrook (see Howe and Smallwood for citations) that suggest plants may use one of two strategies. One strategy is the ...


4

It reminds me of the smooth-barked Australian gum trees / eucalyptus, like a salmon gum, ghost gum, etc. Although there are no squirrels in Australia :) This photo of a Salmon Gum is from http://www.fpc.wa.gov.au/content_migration/plantations/species/arid/salmon_gum.aspx


4

This is a "Tar Spot" disease usually found in Europe and North America. It mostly affects the Maple tree leaves. Tar spot is caused by 'Rhytisma acerinum' a plant pathogen fungus. This pathogen does not seem harm to tree but disturbs the leaves as it finds a suitable condition in summer with bit of wetness. It enters the leaves through stoma and then creates ...


4

According to this news article, in a NASA experiment one man survived for 15 days in a sealed chamber containing 30,000 small wheat plants. If you read the article you will find that this did not produce a completely balanced system - some excess oxygen had to be removed, and some extra CO2 had to be pumped in.


4

I remember overhearing a botanist some 10 years ago, that he cannot tell male poplar from female when they are not flowering or producing seeds. Poplars and willows are related, so it is a weak indication for you, you will likely not find any visible features in willow neither. But it is an old information, too. (Are you interested in DNA sequencing ...


4

The article you have linked to does explain everything thoroughly, though in a somewhat complex way. I did not know how much genetics you actually know, so I tried to answer very thoroughly. So the article states that the gene Mendel studied and that was responsible for the white color of the pea flower is ANTHOCYANIN1 (in the article it is also called - ...


4

Yes, D. Attenborough probably refers to ploidy number Ploidy number Humans for example are 2N (except during the spermatozoid and ovule phase of human existence) meaning that they carry two copies of each autosome (=non-sexual chromosomes). Some species are 1N (haploid), some are 3N (triploid), etc… It would actually be more correct to talk about the time ...


4

It's a Brown-belted Bumble Bee (Bombus griseocollis). Details: http://bugguide.net/node/view/3538


4

Monstera deliciosa seems to fit the bill. From Wikipedia: This member of the arum family Araceae is an epiphyte with aerial roots... Wild seedlings grow towards the darkest area they can find until they find a tree trunk, then start to grow up towards the light, creeping up the tree.[6][dead reference link] Fruit The fruit of ...


4

Is the necessary that stamens have two microsporangia per theca? No. Many species in Cryptocarya group of Lauraceae have microsporangia that have fused such that they have only two microsporangia instead of the typical four (Rohwer et al. 2014). I interpret their description as saying that the microsporangia within a theca but it's not clearly stated as ...


4

Your plant appears to be Chionanthus pubescens, the pink fringe tree, which is native to Ecuador and Peru. The genus has a number of species. It belongs to the family Oleaceae, which includes well known plants like jasmine, forsythia, ash trees and olives. I could not find much biological information on the pink fringe tree but plantlist.org contains a ...


3

Another disclaimer: this is not my field and I am not competent to judge the content of the paper that I am bringing to your attention. I said above that I wouldn't make another contribution, but I found something else worth sharing in this context and which complements the answer from @fileunderwater Wang Z et al. (2012) Capillary Rise in a Microchannel ...


3

The chloroplast, having multiple circular copies of its chromosome and its own tRNA and ribosome genes more resembles the bacterial systems it is descended from. See @A.Kennard comment Polysomes being found in bacteria frequently are single mRNA to which are attached multiple ribosomes. This paper shows that chloroplast polysomes were observed in the mid ...


3

I don't think it's wise to use a spectrophotometer for this experiment, as it is a total count, i.e. it can't distinguish between dead and alive cells very well, and so she might not see a clear difference between her treated and untreated algae. If she has access to a haemocytometer and a good microscope, then she can count the living cells directly, and ...


3

Here's Veritasium on youtube has one explanation which is same as @AlanBoyd's comment.


3

Papain is a cysteine protease, for which Wikipedia should be sufficient: Cysteine proteases play multi-faceted roles, virtually in every aspect of physiology and development in plants such as in growth and development, in senescence and apoptosis (programmed cell death), in accumulation and mobilization of storage proteins such as in seeds. In addition, ...



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