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lina2011 [118]
3 years ago
15

Which do guard cells control?

Biology
2 answers:
Paul [167]3 years ago
6 0
The size of stomata to check transpiration
larisa [96]3 years ago
3 0

Answer : The correct answer is -

c. the size of the stomata.

Guard cells are the specialized cells, which are present around stomata (tiny holes/openings on the leaves) in plants.

These cells regulate the opening and closing of stomata, which help in the exchange of gases and loss of water in the atmosphere that is transpiration.

Thus, it can be concluded that guard cells help in controlling the size of stomata.

You might be interested in
N which vertebrates did feathers first evolve?
Lapatulllka [165]
<span>Wings have evolved several times independently. In flying fish, the wings are formed by the enlargement of the pectoral fins. Some fish leap out of the water and glide through the air, both to save energy and to escape predators. If they were already gliding, then any mutation that would result in an increase of the gliding surface would be advantageous to the fish that has it. These advantageous may allow these fish to out-compete the others. 

Wings have also evolved in bats, pterosaurs, and birds. In these animals, the wings are formed by the forelimbs. In some lizards that have evolved gliding flight, however, the "wings" or gliding surfaces may be quite different. The lizard Draco, for example, has gliding surfaces formed by an extension of the ribs. A number of extinct reptiles have similar gliding surfaces. Frogs that glide have expanded webbing on their hands and feet. Gliding ("flying") squirrels and marsupial sugar gliders have flaps of skin that lie between the front and rear limbs. These gliding animals all have one thing in common: a gliding surface that is formed by enlarging some parts of the body. 

In pterosaurs, the wing is formed by an elongated finger and a large skin membrane attached to this finger. In bats, the wing is formed by the entire hand, with skin membranes connecting the elongated fingers. In birds, flight feathers are attached to the entire forelimb, while the fingers have fused together. In all of these animals except birds, the wing is a solid structure. In birds, however, the wing is formed by a large number of individual feathers lying close to each other and each feather is in turn formed by filaments that interlock. 

Biophysicists have determined that flight most likely evolved from the tree down. That means most active flyers evolved flight from an animal that was already gliding. Gliding was therefore probably an indispensable intermediate stage in the evolution of flight. Since gliding has evolved in so many different groups of animals, it follows that the ancestors of birds, bats, and pterosaurs were almost certainly gliders. 

Unfortunately, the fossil records of the immediate gliding ancestors of birds, bats, and pterosaurs are all missing. The first known bat and bird fossils are recognizable as flyers. The same is true of pterosaurs. Therefore the origin of these flyers remain a mystery and a subject of often acrimonious debate. There are people who claim that dinosaurs evolved insulation, which then evolved into feathers, but the evidence for that is lacking. The so-called proto-feathers found on some dinosaurs are indistinguishable from the collagen fibers found in the skin of most vertebrates. Some of the supposedly feathered dinosaurs, such as Caudipteryx and Protarchaeopteryx, are actually flightless birds. The same is probably true of Microraptor fossils, which are (as Alan Feduccia says) probably "avian non-dinosaurs." 

Even though the immediate ancestor of birds remains a mystery, there is a fossil known as Longisquama insignis, which lived during the late Triassic. It has featherlike structures on its back. It was probably a glider of some sort. So, this animal may well be the distant ancestor of Archaeopteryx, the oldest known bird. 

In sum, flying almost certainly evolved from animals that were already gliding, or from the tree down, not from the ground up. The dinosaurian origin of birds requires that dinosaurs evolved feathers from insulation and flight to have evolved from the ground up. Both of these requirements are extremely unlikely to have occurred in evolutionary history, because dinosaurs are almost certainly ectothermic (or "cold-blooded") and therefore they never evolved insulation, and because feathers are too unnecessarily complex to have evolved as insulation. Flight from the ground up is also dangerous because large animals that attempt to fly from the ground may crash and seriously injure or even kill themselves. We all know how dangerous an airplane can be if it loses power and crashes. Small and light weight animals, OTOH, that were already gliding can survive if their attempt to fly fails. Finally, if flight evolved from gliding, then why do animals glide? The answer is that gliding is energetically much cheaper than to descend a tree, walk along the ground, and then climb up another tree. Besides, it is almost certainly much safer to glide from one tree to another than to be walking on the ground for many arboreal animals. 

See link below for details of why dinosaurs are considered ectothermic according to the available scientific evidence.</span>Source(s):<span>http://discovermagazine.com/1996/dec/aco...</span>
3 0
3 years ago
What is the phenomenon that is causing the bean seedling to bend as shown?
liq [111]

Answer:

phototropism

Explanation:

Phototropism is the phenomenon that is causing the bean seedling to bend as shown.

Phototropism is known to be the growth of a plant or an organism in response to a light stimulus. This means that plants or organisms grow in the direction of the light. From the image shown, we will discover that the bean seedling is bending towards the direction of the sunlight.

This phenomenon usually occur in plants but it can also occur in organisms in fungi.

When the plants grow towards the direction of sunlight, it is known as positive phototropism while when the plants move away from the direction of sunlight, it is known as negative phototropism (skototropism).

5 0
3 years ago
Fires in forests from lightning rid the forest of dead branches and leaves. if the trees survive and the soil remains intact, th
pogonyaev
It is called ecological succession, which can take up to a decade. It is a process of change in the species structure that occurs after a vast loss or extinction. Ecologists study how complexity is evident when a community is formed or occurrence takes place from an empty land or bare soil.
4 0
3 years ago
a solid substance turns into a liquid. which best describes this change? a substance that has a specific volume changes to a sub
BartSMP [9]
A substance that has a specific shape and volume changes to a substance that has a specific volume is the statement that best describes this change in question. The correct option among all the options that are given in the question is the third option. I hope the answer helps you.
8 0
3 years ago
Read 2 more answers
HELP!!! How does the Galápagos penguin compare to the cold adapted emperor penguin of Antarctica?
skad [1K]
<h3><u>Comparison between Galapagos penguin and cold adapted Emperor penguin of Antarctica:</u></h3>

<u>Galapagos penguin:</u>

  • Galapagos penguins are the only species of penguins that live north of the Equator.
  • The Galapagos penguins breed all-round the year.
  • The Galapagos penguins are smaller compared to the cold-adapted emperor penguins of Antarctica.
  • The breeding and nesting place of the Galapagos penguins lie on the shoreline.

<u>Emperor penguin:</u>

  • The emperor penguins live and adapt to the cold Antarctic environment.
  • The Emperor penguins breed only during the Antarctic winters.  
  • The nesting of emperor penguins is on ice cliffs and icebergs where the eggs are protected from the strong and cold Antarctic winds.
  • However, both of these species of penguins are at risk of extinction due to the rise in temperature and shortage of foods.
7 0
3 years ago
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