source : lifeder.com
Which best matches the plant tissue to its function?
A) Vascular tissue transports materials from the environment into the plant.
B) Dermal tissue produces and stores the plant’s food until it is needed.
C) Meristem tissue uses energy from the sun to produce food for the plant.
D) Ground tissue is the outermost plant tissue that prevents water loss
Diagram of a cross-section through the stem of a hypothetical plant showing tissues
The correct answer is A. Vascular tissue transports materials from the environment into the plant.
The plant body is made of several different types of tissues, which have specific functions. For instance, the vascular tissue transports materials from the environment into the plant. This tissue is one of the three main types of tissue that occur in the mature plant.
The other two main types of plant tissue include the ground tissue and the dermal tissue. The dermal tissue is found making up the outer layer, while the ground tissue is more internally located.
Meristem tissue really gives rise to all the other tissues of the plant and contains many actively dividing cells. An individual tissue consists of a group of cells that have a similar structure and function. In fact, tissues can be either simple or complex depending on their function in the plant body.
Cell division and cell elongation allow the plant body to grow. The meristematic regions are responsible for much of the development and growth of the tissues. Many of the cells and tissues differentiate as the plant matures so as to form the different tissue layers.
Meristems are tissues that actively divide to give rise to the other tissues of the plant. There are different types of meristem depending on whereabouts the cells are located in the actual plant.
For instance, apical meristems are found at the tips (apex) of shoots and roots, while lateral meristems are found in other parts of the plant aside from the tips.
Intercalary meristems are found at the base where leaves attach on the stem. In comparison, the lateral meristems can be found where vascular tissue is and gives rise to the secondary tissue which in fact enables the plant to grow in width.
The ground tissue consists of cells that provide support and store food for the plant. The predominant cells of this tissue are the parenchyma cells.
These can be variously modified for different functions. Supportive cells that occur in the ground tissue include the collenchyma cells and sclerenchyma cells.
The parenchyma cells are the most abundant cells of the ground tissue, and they have several functions including the ability to divide to repair and replace injured plant tissue.
A further function of these cells is to store foods such as starch and oils. In addition, cells may become modified for photosynthesis and in that case, they form the mesophyll of the leaf.
The parenchyma that forms the mesophyll contains many chloroplasts and is involved in the photosynthesis reactions of the plant.
The collenchyma is a tissue that consists of cells in which parts of the cell wall have been thickened by cellulose. These cells are important in providing support to stems and leaves and are often destroyed when a plant becomes woody.
This tissue is thus most important in providing support to herbaceous plants and to the plant body while it is still growing in the case of young woody plants.
Sclerenchyma also provides support to the plant, but unlike collenchyma, these cells are often dead at maturity.
The cell walls, in this case, are thickened with the substance lignin, and these cells are typically found in parts of the plant that have stopped growing and elongating. The sclerenchyma cell walls are not flexible in the way that collenchyma cell walls are, but are rather rigid.
The vascular tissue of the plant consists of xylem and phloem cells, which are responsible for transporting water and sugars around the plant. The cells of the vascular tissue form a system of tubes that transport substances through the plant body.
The xylem is the tissue that transports water and dissolved minerals through the plant. The primitive cells are known as the tracheids, which are long tapering cells that join end to end.
The more advanced cell types are the vessels which are thicker cells that also join to each other. The vessels are better able to transport water and are found in the more evolutionarily advanced plants.
Water is taken up from the soil and moves through the cells to all parts of the plant body. In addition, xylem can form wood when a plant matures and secondary xylem is deposited.
Phloem is vascular tissue that is involved in transporting food substances around the plant. The main cells that are present are sieve tubes and companion cells.
Sieve tubes are cells which have holes at the ends of the cells which function as a sieve to allow food particles to move from one cell to another. Secondary phloem can form in some types of plants and can form bark in woody plants.
The dermal tissue includes the cells that form the outer layers of the plant. This includes epidermal cells which are the most numerous, and also occasional guard cells which surround stomata. Stomata are openings into the plant which allow for gases to enter and leave.
These openings are important for photosynthesis which requires oxygen to be taken into the plant. Some water is lost through the stomata which is why it is important that they be able to close. Guard cells are bean-shaped cells that are specialized to open and close the stomata.
Epidermal cells are closely packed to form a protective outer layer for the plant. The cells are usually only one layer thick but in some cases where the plant is in an extreme climate, it may be more than one layer thick.
These cells also secrete a wax that forms a waxy cuticle that covers the plant surface. This helps protect the plant and prevent water loss from the surface.
Editors of Encyclopedia Britannica (2018). Meristem. Retrieved from Encyclopedia. Britannica.
Editors of Encyclopedia Britannica (2018). Parenchyma. Retrieved from Encyclopedia. Britannica.
Editors of Encyclopedia Britannica (2018). Collenchyma. Retrieved from Encyclopedia. Britannica.
Editors of Encyclopedia Britannica (2018). Xylem. Retrieved from Encyclopedia. Britannica.
PH Raven, RF Evert, SE Eichhorn (1987). Biology of plants. Worth Publishers.
Which type of tissue correctly matches with its location? – Areolar tissue is present in the skin and binds the outer layers of skin to the muscles beneath. Transitional epithelium forms the lining of the wall of Cuboidal epithelium is commonly found in ducts of glands and tubular parts of nephrons in kidneys and its main function is absorption and secretion.The best match to plant tissue to its function is "Vascular tissue transports materials from the environment into the plant." Dermal tissue protects the plant from injury and water loss. Meristem tissue are found it parts of the plant that are growing.The plant body is made of several different types of tissues, which have specific functions. The more advanced cell types are the vessels which are thicker cells that also join to each other. The vessels are better able to transport water and are found in the more evolutionarily advanced plants.
Which best matches the plant tissue to its function? – Brainly.com – Plant Tissue – Meristematic – Simple, Complex Permanent Tissue. 1038 x 527 jpeg 84 КБ. bio1520.biology.gatech.edu. Which best matches the plant tissue to its function 533 x 420 png 295 КБ. www.slideshare.net. Plant Biology – Tissues.the functions of epithelial tissue are extent sustainable intensification would allow humanity to meet its demand for food commodities. here we use the footprints for water, nitrogen, carbon and land to quantitatively evaluate resource demands and greenhouse gas (ghg) emissions of future agriculture…Match the parts of the sentences and write down the text: Many people. the bleeding as soon as possible. Shock occurs when the heart is unable to supply enough blood to the organs. This results in a slowing down of the vital functions, and can cause death.
Which best matches the plant tissue to its function? – lifeder English – SAT biology subject practice test 11: Plants. This test contains 5 SAT biology Plants questions with detailed explanations. A. I only B. II only C. III only D. I and II E. II and III. 2. Which of these correctly matches the plant cells to their tissue systems?Plant Tissues. Plants are multicellular eukaryotes with tissue systems made of various cell types that carry out specific functions. Meristematic tissues consist of three types, based on their location in the plant. Apical meristems contain meristematic tissue located at the tips of stems and roots, which…Start studying Plant structures. Learn vocabulary, terms and more with flashcards, games and other study tools. Which best matches the plant tissue to its function? Vascular tissue transports materials from the environment into the plant.
Animal Tissues – .
Microscopes and How to Use a Light Microscope – Captions are on! Click CC at bottom right to turn off.
“Pinky, what is on the kitchen table?” “Oh, it’s my protists. I’m hoping to
find some euglena, maybe some paramecia. I took this sample from—”
“Stop, I mean, WHY is it on the KITCHEN table?!” “Oh, I got distracted. I was going to take some drops and put it
on a slide while I set up my microscope.” “Yes, well, please get your green water
away from where we eat.” “Green water? Don’t be ridiculous, Petunia,
there are tons of protists in here. We just have to find them.” “Well, I think you’re out of luck.” “The protists that I’m looking for are
unicellular, meaning, they’re made up of one cell. And generally, you need a microscope
to see them.” “Huh. Never used one of those.” “You’ve…never used a microscope before?” “No.” “Well you know what that means?” “I’m afraid about what that means.” “We must explore the world of…microscopes!” First of all, let’s focus on a few terms
that are important in order to understand microscopes. Magnification is one. That’s really what most people think of
when they think of a microscope. And we’re going to talk more about that
in a moment. But another term that is important is resolution—basically,
are you able to distinguish between two objects? This is important as otherwise two objects
could actually look like one object, because you can’t distinguish between them. So, for example, if a microscope had a resolution
of 0.2 microns, that means two objects needs to be 0.2 microns or more apart in order to
see that they are two different objects and not one. If you want to understand the physics
of how resolution works and how it’s calculated, we have a great further reading suggestion
in the video details. So let’s talk about some different types
of microscopes that all take into account this need for magnification and resolution
in order to see specimens. First, light microscopes. If you’re in a classroom, this is likely
what you have. And, as its name would suggest,
it uses light in order to see an image. Brightfield light microscopes tend to be what
people are familiar with- typically producing a darker
image on a light background. With a darkfield
light microscope, you have a piece that blocks the light source, called a light stop. The
idea is that most light has been blocked so the only light you see is light reflected
or refracted from structures within the specimen that you’re looking at. So, you tend to
see light images on a dark background. There are many other types of light microscopes
too. We have a great link for further reading
suggestions to learn how each of these work, and some of these are fascinating—some rely
on interference, some rely on using a laser…but the thing to keep in mind is, there are certain
times when one of these types of light microscopes is more ideal than another. For example, a
phase-contrast microscope can give you a very detailed image of a living specimen without
requiring any stain, and the detail it provides can be far better than the typical brightfield
microscope. So light microscopes use light in some form
to see a specimen. But not all microscopes
are light microscopes. For example, what if we wanted to see a virus? Viruses are generally
very small- typically much smaller than the average bacterium. How can we increase magnification
and resolution abilities to see them? That’s where electron microscopes come in. Electron
microscopes use electron beams to visualize images. Transmission Electron Microscopes
(TEMs) tend to be most ideal for visualizing structures within a specimen while Scanning
Electron Microscopes (SEMs) tend to be most ideal for visualizing the 3D surface. Let’s come back to the typical microscope
you might see in a classroom, which happens to be the one that I own. A brightfield light microscope. Here is our light source. Light passes through this, the condenser lens
to focus the light on the specimen. The level of light can be adjusted by this,
the diaphragm. Our specimen—likely
to be on a microscope slide—will be placed on the stage here. Light will be reflected,
refracted, or absorbed by the specimen. But we rely on these lenses here—the objective
lens and the eyepiece lens—to get our total magnification. In fact, this is often referred
to as a compound microscope, because it has two sets of lenses. You can see that the objective
lenses are attached to this revolving nose piece which allows them to be rotated so you
can select a certain one that you want to use. With my particular microscope, I have
three objective lenses. A scanning objective lens that magnifies 4
times, the low power objective lens that magnifies 10 times, and
the high power objective lens which magnifies 40 times. But don’t forget the eyepiece lens because
that also magnifies images, and my particular eyepiece lens magnifies 10 times. So let’s say I use the scanning objective
lens. I would multiple that objective lens magnification
level by the eyepiece lens magnification level so that my total magnification is 40
times. Now, you’ll also notice there’s a lot
of knobs here. Let me introduce you to the
knobs. This large knob here is known as the coarse
focus and then this smaller knob here is known as the fine focus. Both of these knobs raise or lower the stage,
which helps with focusing. The coarse focus knob will move it more dramatically
whereas the fine focus knob will move it in smaller increments. These knobs- the stage knobs- don’t move
the stage up and down but rather from side to side instead. It helps you explore what’s
on the slide itself, but it isn’t adjusting the focus of it. Not all microscopes have
those stage knobs; sometimes you have to move the slide manually. This is the microscope arm and the base. Whenever you pick it up, you want to make
sure you have one hand underneath supporting the base
and the other hand holding the microscope arm. Since it plugs in, you want to make sure there
isn’t water around it. So, let’s take a look at what’s in this
water sample here. I’m going to do something
called a wet mount to prepare my microscope slide. I’m going to drop a drop or two of
my water sample onto the slide using a disposable pipette. It’s like a very fancy eyedropper. Kind of. I’m going to put a cover slip on top. There’s some techniques to doing a
wet mount to avoid air bubbles that you can check out online. Air bubbles actually can
look kind of beautiful under the microscope—which can lead to great disappointment when you
find out they’re not some amazing microscopic organism but rather just an air bubble—
something I may or may not know by experience. I’m going to put the slide on the stage. I’m going to use the stage clips here to
secure the slide. Light is on, and I already have the scanning
objective lens here ready to go, which is good, because I want to find
the specimen first. I can adjust the light
level if I want—but just know that super bright doesn’t always mean the best image. I can look through the eyepiece and use the
coarse focus knob to move the stage up or down slightly to focus. Patience. Euglena! I can also fine-tune focus it with the fine
focus knob. I can use the stage knobs to center my image. Now that I found it with the scanning
objective lens, I’m now going to move up to the next magnification level. So, remember,
total magnification would be 100 times. Since I had already focused it with the scanning
objective lens, it’s likely I only need to use the fine focus knob to adjust the focus
at this level. I could continue to move up to the high power
objective lens, which would give me a total of magnification of 400 times. Now 3 additional tips about using microscopes
that I just want to mention. 1) Most microscope slides are glass so they
can break if dropped. And if using cover slips,
keep in mind they are extremely easy to lose if not careful. 2) Always be aware of where the slide is when
you’re moving the stage up and down with the focus knobs. It’s possible to move the stage too close
to the objective lens and actually crush the slide. 3) If it’s hard to see your image even when
focusing, you may need to clean the lens. But you need to do this by wiping it with
lens paper. Not regular tissue. When you’re done with the microscope, make
sure the slide is removed, turn off the light, lower the stage to its lowest position, and
return the lowest power objective lens over the stage. Unplug it and wrap up the power cord. And if you have a cover, cover the microscope
before putting it away. Keep in mind there are some techniques to
better visualize some specimens such as using different stains or using immersion oil at
high magnification to increase resolution. Definitely something to explore that this
video doesn’t go into. Microscopes open up an entire world that you
can’t see with the naked eye. Microscopes
can also complement what you might be learning in life science. Studying mitosis? Check out
the cross section of an onion root tip, where lots of mitosis happens. Studying plant responses? Take a look at stomata from a thin sample
underneath a leaf. Studying osmosis? Take
a look at how aquatic plant cells respond to different salt concentrations. Endless
possibilities to explore endless curiosity. Well that’s it for the Amoeba Sisters,
and we remind you to stay curious. .
There Are More Than Two Human Sexes – [♪ INTRO] In high school biology, we usually learn that
the sexes in humans are fixed and concrete.
Whether you’re male or female is black-and-white
and rooted in your DNA: your 23rd pair of chromosomes is either two X chromosomes or
an X and a Y. That’s it. End of story. And that’s essentially what scientists thought,
too. But it turns out that sex isn’t that straightforward. In fact, biologists today are saying sex is
a spectrum. And the scientific community is still working
on understanding and respecting the people who fall in the middle of that spectrum. To get this out of the way right up front:
we’re not talking about gender or sexuality here. Gender refers to social and cultural attributes
and understandings of men and women and their roles—though, not every culture has only
two categories, and it’s increasingly seen as a spectrum. Plus, the gender you identify as may or may
not be the same one as what you express with things like your clothing and behavior, all
of which can also be on a spectrum. Sexuality describes who you are attracted
to, and it can be equally complicated and on a spectrum. And where you are on these
spectrums isn’t necessarily fixed! But what we are talking about today is your
biology, including your chromosomes, your hormones, your gonads, and your genitals. The catch is that these biological features
don’t always agree with each other. And they certainly don’t always conform
to those high school health class diagrams that tell us there is a single, universally
correct pathway to being male and female. In fact, it’s estimated that nearly 2% of
live births are born with congenital conditions of atypical sex development. That basically
means that something in their chromosomes, hormones, gonads, or genitals is different
from what many people expect of a “boy” or a “girl.” This used to be known as being intersex, but
these days, it’s better described as having differences of sexual development, or DSDs. And while nearly 2% might not sound like a
lot, it means there could be 130 million people or more with DSDs. If all those people were
in one country, it'd be among the top ten most populous countries in the world! Plus, DSDs are not always something you can
see. People can spend their whole lives thinking they’re one sex based on anatomy only to
find at least part of them tells a different story. You see, your sex is the result of both sexual
determination and sexual differentiation. Sexual determination has to do with what chromosomes
you get. Those largely determine what happens to your body during sexual differentiation—the
process by which you develop the physiological characteristics associated with your sex. And contrary to what you might think, that
differentiation doesn’t stop when you’re born—it continues throughout your life. That means there are a lot of moments where
differences between people can happen—so of course there are a ton of different outcomes! We tend to put those outcomes into two boxes
based on visible anatomy, or what scientists call phenotypes. Phenotypical males have testicles
and a penis, while phenotypical females have ovaries, a uterus, a vagina, and vulva. But in reality, none of the traits we use
to discriminate between the sexes are truly binary. There’s a lot of variation within what we
call male or female, and there's a lot of overlap that's normal, too. Anatomically, someone might look phenotypically
female on the outside but not have ovaries or a uterus, or have tissue from both ovaries
and testes. And genetics aren’t any clearer, because
when it comes to chromosomes, people don’t always get two Xs or an X and a Y. Xs and Ys contain genes that help determine
sex, with the Y chromosome conferring the genes that enable you to develop male reproductive
parts. But the processes for producing sperm and
eggs are really complicated, and they can lead to lots of different results. In this process, (abbreviated version) specialized
cells basically duplicate themselves, then undergo two rounds of division to produce
reproductive cells, or gametes, that have half of the parent’s genetic material. So,
it makes one set of 23 chromosomes. But sometimes, the chromosomes don’t split
into exact sets of 23—and that means there are a whole bunch of possible combinations
of Xs and Ys that a person can end up with. For instance, people can inherit three Xs
or an X and two Ys. These folks are normally taller than average. Those with three Xs have slender builds, and
sometimes have minor learning disorders. The people who have an X and two YYs, on the other
hand, tend to have more acne because of the extra testosterone in their systems. In both
cases, people retain full fertility. Then, there’s Turner syndrome, which happens
when you get just one X. That results in female characteristics, but the people who have it
tend to be shorter, don’t really go through puberty, may have mental disabilities, and
are sterile. And Klinefelter syndrome, which results from
two Xs and a Y, is the most common chromosomal sex anomaly. It happens in one in 600 male births and can
cause lower testosterone production and cause incomplete testicular development, though
the symptoms can be minor enough that a person isn’t diagnosed until later in life. Now there’s also the fact that all your
cells in your body don’t necessarily have the same chromosomal makeup. Which like, what?
Did I learn nothing but lies in high school? But it’s true—someone with mosaicism can
develop from a single fertilized egg, but have a patchwork of genetically different
cells. And someone who’s a genetic chimera has
different cells because they develop from two different fertilized eggs that merge in
the womb. In both cases, it’s possible to end up with
a mix of cells with different sex chromosomes. And depending on the distribution of those
cells, mosaicism and chimaerism can result in ambiguous sexual characteristics or both
male and female reproductive body parts. It’s even been shown that pregnant people
and their fetuses frequently swap stem cells through the placenta in a phenomenon known
as microchimerism. That means a chromosomal “female” can be carrying around XY cells,
and her son can have XX ones. In some studies, these cells have been shown
to stick around in the mother for several decades. But all that said… there are also plenty
of people with double-X or XY chromosomes that also have differences of sexual development. That’s in part because at least 25 genes
play a role in sex differentiation. So both mutations and relocations of these genes can
result in a range of differences. Genes necessary for male development can be
swapped onto the X chromosome, for example, or someone can end up with multiple or mutated
versions of other sex-determining genes. And some of these are on other chromosomes,
and are inherited as run-of-the-mill recessive traits. All of these genes really start to be influential
around six weeks of development. You see, at six weeks, the fetus has a pair
of bulges called the gonadal ridges next to its kidneys—and they have the potential
to develop into ovaries or testes. The fetus at this point also has two sets
of ducts. One set can develop into the uterus and fallopian tubes, while the other set has
the potential to become the epididymis, vas deferens, and seminal vesicles. And what happens from there is somewhat of
a balancing act of different genes working in concert. Essentially, different networks of genes shout
MALE and FEMALE, and when that balance gets knocked slightly askew, it can move a person
along the sex spectrum. Take SRY. Discovered in the 1990s, this is
the male programming gene, and it has a big effect on development. If it ends up on the chromosome of someone
who is XX, it can cause them to develop testes instead of ovaries. This can happen because there’s a step in
sperm and egg production when chromosomes swap some DNA with their partner chromosomes. And even though the X and Y chromosomes generally
don’t join in on this DNA swapping process, they sometimes do. Plus, other mutations that occur during the
production of gametes can result in multiple or mutated versions of SRY or other sex-determining
genes—because it’s not the only gene that matters. There are also genes that actively encourage
the fetus to develop female characteristics. For instance, the gene WNT4 suppresses testicular
development and promotes ovarian development, and multiple copies of it can cause incomplete
female gonads to develop in people who are XY. Gonad development also triggers the production
of sex-specific hormones, which results in further sex-specific development. But some people have differences of sex differentiation
that limit their ability to respond to those hormones. Complete androgen insensitivity syndrome is
one of these. People who have it are unaffected by male sex hormones, because they have some
kind of mutation to the protein that these hormones bind to, called the Androgen Receptor. And that means that while they have testes
and a Y chromosome, their exterior genitals appear female or in between. There’s also congenital adrenal hyperplasia,
the most common DSD out there. That’s when the adrenal glands underproduce
cortisol and overproduce androgens, the male hormone group that includes testosterone. The underproduction of cortisol can lead to
health problems, while the overproduction of androgens can lead to external male genitalia
paired with internal female gonads in people with XX chromosomes. Some of these conditions don’t fully present
themselves until puberty or later. In fact, some aren’t realized at all until
a person seeks some kind of medical care that reveals them. Like, in 2014, doctors reported
one case of a 70-year-old father of 4 whose quote “hernia” turned out to be a uterus
with fallopian tubes. But, in many cases, differences in sexual
development are notable from birth; for those newborns, it may be possible to assign a gender
based on what they are more likely to identify as, as they grow up. The thing is, with all of the things that
can happen during sexual development, when a child is born with an obvious difference
of sex development, it's not always clear why. Looking at chromosomes often isn’t enough,
and sometimes a hormonal test isn’t either. And even if the child’s doctors have a sense
of what’s going on, determining what, if any, treatment is necessary can be challenging. Back in the 1960s, it was thought that growing
up without clearly defined sexual organs would cause emotional trauma. So, there was a push
towards performing surgery on infants to clearly assign them a sex. And because of social stigmas surrounding
DSDs, parents were often encouraged to keep all this a secret, even from the child. So
people grew up without knowing kind of important details about their own bodies. It’s hard to get numbers on how many of
these surgeries were—or even are being—performed. It’s also hard to know exactly how these
surgeries affect patients, but as adults, many report pain, scarring, and a loss of
sensation. Also, people with DSDs do report high rates
of gender dysphoria, where their chosen gender does not align with their assigned sex. And there is an association between gender
dysphoria and mental health issues, like self-harm behaviors, so these surgeries may contribute
to mental health problems later in life. Though, it’s important to note that such
issues are less likely if people have supportive and affirming parents who accept them as they
are. And, sometimes, surgery is medically necessary,
like to unblock the urethra. Also, surgery can help to preserve fertility
or, in the case of complete androgen insensitivity syndrome, to reduce the risk of testicular
cancer. But from a medical perspective, those surgeries
don’t need to be performed on infants. In fact, most of the time, differences in
genital anatomy at birth aren’t something that needs to be fixed. At least, not until
the person is old enough to make their own choices about what they want their bodies
to look like. So nowadays, healthcare is moving away from
a surgical approach. If a DSD is identified at birth, treatment is more likely to include
therapy and hormonal replacement than surgery. Often, a DSD team is involved in care, which
can include geneticists, endocrinologists, and psychologists or psychiatrists. They help the family decide if any interventions
are immediately and medically necessary, and help provide care and support to the child
with DSD and their family throughout childhood. Unfortunately, this kind of care still isn’t
available everywhere. For now, researchers are working to better
understand the development of both sex and gender over time, and to gain a clearer sense
of when kids begin to understand their own gender identity. The problem, of course, is the fact that from
clothes to restrooms to organized sports, they are raised in a society that is set up
around a binary that just… isn’t binary. But researchers are thinking about how we
can make our overall discussions and understanding of sex even more inclusive—and more accurate. Because even though biological sex may seem
like one of those things that is relatively straightforward in a very, very complicated
world… it’s not! And while there’s probably still a long
way to go to understand it, we are making progress. Before we go, we’d like to give a special
thank you to our patrons on Patreon. It’s because of their support that we’re able
to tackle complex, difficult topics like this one. So thank you, patrons! And if you want
to support us, too, you can learn more by joining our patron community at Patreon.com/SciShow [♪ OUTRO] .