Answer:
Earth-orbiting astronauts are weightless for the same reasons that riders of a free-falling amusement park ride or a free-falling elevator are weightless. They are weightless because there is no external contact force pushing or pulling upon their body.
What is responsible for the red tide phenomenon? It is a phenomenon that usually coincides with storm surges; the name comes from the red kelp that often washes ashore as a result of rough weather. Red tide occurs in patches of water where certain species of dinoflagellates flourish. They are so abundant that the water becomes discolored and takes on a red hue. Red tides occur once a year and in accordance with the lunar cycle. The water appears red as a result of reduced levels of photosynthetic pigmen
Answer:
Red tide occurs in patches of water where certain species of dinoflagellates flourish.
Explanation:
Red tides refer to the noticeable microalgae proliferation that can be recognized for being a big spot in the sea of a characteristic coloration. This phenomenon is caused by two microalgae groups: diatoms and dinoflagellates, both part of phytoplankton.
Red tides occur when certain environmental factors -such as temperature, light, nutrients availability, ph, etcetera- favor the overproduction of these organisms. These species produce toxins that turn to be dangerous for other animal species that feed on them.
Because these microorganisms produce pigments, their accumulation on the sea surface can be noticed as reddish, brown, or greenish color spots of variable extension.
Single-celled organisms with cell walls do not have contractile vacuoles. Suggest why.
Which of the following statements support(s) the theory of the endosymbiotic origin of chloroplasts?
Chloroplasts have their own DNA, separate from the DNA in the nucleus.
They contain their own ribosomes to translate and make proteins.
They self-replicate and reproduce on their own.
They don't have similarities to photosynthetic prokaryotes.
I only
I and II only
I,II, and III
I, II, and IV
Answer:
C
Explanation:
According to the endosymbiotic idea, a few eukaryotic cells' organelles were previously prokaryotic microorganisms. Chloroplasts and mitochondria divide by binary fission. Therefore, option (C) is correct.
What is Endosymbiotic Theory ?According to the endosymbiotic theory, eukaryote cell organelles like chloroplasts and mitochondria descended from separate bacteria that eventually developed symbiotic relationships with other cells.
Both mitochondria and chloroplasts have circular, single-stranded DNA in addition to not having histones. Prokaryotes are the only organisms that have single-stranded, circular DNA. They contain their own ribosomes to translate and make proteins. These qualities would enable the mitochondria and chloroplasts to thrive on their own, supporting the endosymbiosis theory.
Therefore, option (C) supports the theory of the endosymbiotic origin of chloroplasts.
Learn more about endosymbiotic theory, here:
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which of the following are human activities that can negatively impact ecosystems.
Answer:
Hey not sure if there is something that is supposed to be viewable but some common human activities that can impact ecosystems are, deforestaion, pollution, littering, fracking, spilling oil into the oceans.
Explanation:
Answer:
You didn't put a photo but cutting down trees of putting chemicals into the water/earth can harm ecosystems
mitosis cell division are required to form 64 cell for one cell?
a.4
b.6
c.16
d.32
Answer:
im not sure
Explanation:
The area where the two chromatid halves of a chromosome
are joined is called a
A. centrosome
B. metaphase plate
C. centromere
D. mitotic spindle
How are gymnosperms in category gnetophyta usually pollinated?
A. by wind
B. by hand
C. by insects
D. by water
Answer:
by insects
Explanation:
answer f and g urgently
it relates to the picture
A dependent variable is:
Answer:
the variable that is being measured or tested in an experiment
Explanation:
just fax
Frequently, a group of related species will each have a unique courtship ritual that must be performed correctly for both partners to be willing to mate. Such a ritual constitutes a ________ ________ reproductive barrier. Group of answer choices
Complete question:
Frequently, a group of related species will each have a unique courtship ritual that must be performed correctly for both partners to be willing to mate. Such a ritual constitutes a ________ ________ reproductive barrier.
Group of answer choices
A) behavioral . . . prezygotic
B) mechanical . . . postzygotic
C) temporal . . . prezygotic
D) gametic . . . postzygotic
Answer:
A) behavioral . . . prezygotic
Explanation:
The biological concept of species states that individuals of a species can not mate and reproduce with individuals of another species. But if they get to reproduce, the progeny will not be viable or fertile. There will not be any reproductive success.
There are different reproductive isolation mechanisms, which are barriers that inhibit or interrupt the genetic flow between different species.
Reproductive barriers are isolation mechanisms that prevent mating between two or more species. The prezygotic mechanism avoids fertilization between individuals of different species, while the postzygotic mechanism impedes the zygote to develop and reach the adult stage.
There are different types of reproductive barriers.
Pre-copulatory o pre-ziygotic:
Ecological or by habitat isolation; Seasonal or temporal; Sexual o ethologic; Mechanic; Gametes incompatibility.Postzygotic mechanisms or barriers include
Hybrid inviability, Hybrid sterility, Hybrid reduced viability or fertility, Cytoplasmic interactions.Behavioral isolation is also known as ethological isolation or sexual isolation. This is a prezygotic barrier that refers to the fact that even when many species occupy the same area, they are not sexually attracted to each other, and might be rejected because of behavioral factors, not getting to mate. This mechanism includes courtship patterns or mating rituals and specific chemical signals that allow recognition between individuals of the same species.
Which animal would most likely move fastest in the water?
(1) Sailfish
(2) Seahorse
(3) Blowfish
(4) Octopus
Answer:
Sailfish
Hope it is helpful
Forensic anthropologists are trying to determine the age of a male skeleton that has been uncovered. They conclude that he must have been between 16 and 19 judging by the measurement of his
ribs
clavicle
pelvic bone
tibia
According to the food pyramid what contains large amounts for the making of cell membranes
Fatty acids
Explanation:
Essential fatty acids need to be consumed through the diet and are important building blocks of cell membranes.
As carnes lombinas e animais de bom porte alimenticio e apropiados para "consumo"(no caso , que pode ser ingerido).
state two forces that occur when two metals meet together
Answer: repel forces and attract forces
Helpppppp please!!! How do membrane proteins contribute to the membrane potential?
Answer:
the answer is B
Explanation:
the answer is b
No.3 plzz ...?
Any one
2^n=32
n=5
It doesn't really match up with the options so not sure, my best guess would be either choosing 16 or 4. 16 in case the person calculated as 16 times 2 = 32 and 4 bc its the closest.
You observe a cell in a stained section of connective tissue. The cell has an indented nucleus and obvious cytoplasmic granules. Upon further testing, you determine that the granules contain histamine. This cell is most likely a(n) _____. Multiple choice question. mature neutrophil mast cell eosinophil B cell
how can so much DNA could fit inside a bacterial cell.
Answer:
The reason so much DNA could fit inside a bacterial is because the DNA are double-stranded, looped, coiled, and foleed into the cell. The DNA is tightly fitted around the nucleus.
Explanation:
Have a great summer :)
Which method gives the actual age of a fossil in years?
Answer:
Radiometric dating methodsExplanation:
Researchers use a clock to estimate the date a rock or fossil was produced in order to ascertain its age. Radiometric dating methods, which are based on the natural radioactive decay of specific elements like potassium and carbon, are widely used by geologists to date ancient events.
OAmalOHopeO
10 pc
Tiffany wants to know the effect of eating sugary snacks on
performance in PE class. She decides to set up an experiment to find
out. Which of the following groups of individuals would be in the
control group?
n
Students who take a PE class at their school.
Students who take a PE class and who will not be eating sugary snacks before PE
class.
Students who take a PE class and who will be eating sugary snacks before PE class.
Students taking any class at school eating any food.
Answer:
Students who take a PE class and who will be eating sugary snacks before PE.
Explanation:
The control variable (or control group) is an experimental element which is constant or unchanged throughout the course of the experiment.
The option "students who take PE class and who will be eating sugary snacks before PE" will remain unchanged and constant because the whole point of the experiment is to see the effects on students performance in PE after eating sugary snacks.
Hope this helps :)
(h) Which one of the following favours the fastest transpiration rate ? (i) A cool, humid, windy day (ii) A hot, humid, windy day (iii) A hot, humid, still day (iv) A hot, dry, windy day
Answer:
Hot temperature, dry and windy environment causes fastest transpiration rate.
option IV
Select all that apply.
Which conditions relate to the research of van Helmont?
plant mass related only to soil
conclusions partly correct
demonstrated plant food from soil
conducted around 1400 AD.
plant mass related to H 20
Answer:
I'd say the best Answer is A & C
Explanation:
Do populations of different species of birds that live in the same community compete? Explain.
Please help me
Which of the groups below has suffered the greatest percentage of species extinctions since 1600 (A) birds, (B) fishes, (C) mammals, (D) reptiles
(a) Birds is the correct ans
Explanation:
.......
Answer:
My guess would be mammals
Explanation:
Habitat destruction
Please help me...will give braniliest
write a short note on akaryotic cells
Answer:
Eukaryotic cells have a nucleus enclosed within the nuclear membrane and form large and complex organisms. Protozoa, fungi, plants, and animals all have eukaryotic cells. ... They can maintain different environments in a single cell that allows them to carry out various metabolic reactions
Answer:
Explanation: Akaryocytes, also known as akaryotes or acaryotes, are cells without a nucleus. The most common type of akaryocytes are viruses. The name is derived from the Greek prefix "a-", meaning "without" and the Greek "karyo-", meaning "nut" or "kernel". ... This cell biology article is a stub.
give a short introduction of carl von linnaues and rh whittakers regarding classification of living beings one major point
Define the word ⇒ Biosphere
THANK YOU!! :)
The biosphere is a narrow zone of the earth where land, water, air interact with each other to support life.
Answered by Gauthmath must click thanks and mark brainliest
which of these resources can not be renewed? A. Solar B. Coal C. Wind D. Biomass
Answer:
coal
Explanation:
it is a non renewable energy source
There are four different combinations of offspring genotypes in every Punnett square. Fill in the blanks below to complete the ratio for the Punnet square shown to the right.
Where's the Punnett square?
