gymnosperms and angiosperms only. Potonié first postulated the presence of such a class of intermediate plants between pteridophytes and seed plants in 1899.
However it is now understood that ferns are not seed plants primary relatives. Compared to previous groupings like the clubmosses and ferns, gymnosperms have a number of important evolutionary novelties. They create pollen that contains, and the wind carries it to the female. These plants are no longer dependent on water for reproduction thanks to this invention. A relatively tiny class of plants known as gymnosperms produce "open seeds" and lack flowers. This means that unlike in a fruit, where the seeds are formed inside the reproductive structure, they are produced on the surface of the reproductive structure.
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In the oceans on either side of the Isthmus of Panama are 30 species of snapping shrimp, 15 species on the Pacific side and 15 different species ch the Atlantic sid. See different water depths. Morphological and genetic data show that Atlantic and Pacific species that live at similar depths are sister species. Geological evidence indicates that the Isthmus of Panama started rising about 10 million years ago and the oceans were completely separated by the stimus about 3 million years ago. If the geological evidence has been misinterpreted and the isthmus had formed very rapidly in less than 1,000 years), which of the following predictions is most likely?
A. greater percentage of difference in DNA sequences between sister species that inhabit deep water than between sister species that inhabt stalow water
B. greater percentage of difference in DNA sequences between sister species that inhabit shallow water than between sister species that inhabit deep water
C. similar percentages of difference in DNA sequences between all pairs of sister species
D. greater percentage of difference in DNA sequences between Atlantic species than between Pacific species
Answer:
The answer is "Choice A".
Explanation:
The Panama isthmus is indeed a patch of land which separates its sea from its Atlantic ocean to The pacific in two halves. The Panama Isthmus allows spreading the seafood applicable state, although due to geographical barrier, the very same turtle species were isolated. Its deep squirrels of liquid are diverged quite early as being against shallow water shrimps which are characterized by the rising of the Jamaica isthmus, first off the island can be crossed until it was closed through shallow water prawns and shallow-water animals. If Panama's black sea was established less than 1000 years, it has a greater effect on deepwater shrimp and very low water lobsters. Consequently, in water depth prawns, a disparity in hereditary degree (DNA) is higher than in shallow species. The deep waters have been affected earlier so the variation in DNA sequences throughout all sister species will not be the same.
A biologist studies a population of anteaters living in a large nature reserve. The reserve is surrounded by farms where anteaters are not safe, but the reserve is a perfect place for anteaters: there are few predators and lots of ants. The biologist counts the number of anteaters in the reserve every year for twenty years and finds the size of the population does not change much. Which of the following is the best description of what life in this reserve is probably like for these anteaters?a. The anteaters have little or no difficulties obtaining food and raising offspring. ants. Their tongues are 24 inches long and covered with sticky saliva. Anteaters cannot open b. Adult anteaters compete for food and many young anteaters die. theirmouth, and do not have teeth. Even the stomachs of anteaters are unique: unlike most mammals,c. It is impossible to know without actually observing anteaters in the reserve.
Answer:
Adult anteaters compete for food and many young anteaters die
Explanation:
As there are not many predators and the number of ants is abundant, the population of anteaters should grow on a large scale, however, this is not what happens, since the size of the population is the same for twenty years. This shows that the anteater population itself is regulating the size of the population through internal disputes, where anteaters, due to the high birth rate, end up competing for food and shelter, causing the most young and inexperienced individuals to be killed.
PLEEASEEEEEEEEE HEELPPPPPPPPPPPP
Answer:
1) bone marrow
2)stores fat
3) calcium
4)tough tissue
Write the correct type of mutation that occurred in creating the mRNA strand for each of the following
examples. Original DNA: ATCCGCTTACG
a. UUGGCGAAUCG: __________________
b. UATGGCGAAUCG: _________________
c. UGGCGAAUCG:__________________
Answer:
a. the second nucleotide is wrong. It is a U but should be an A. No other nucleotides were effected by this, only the one was effected. This is a Point (Substitution) Mutation.
b. the third nucleotide is wrong. It is a T that was inserted. As you can see, the rest of the nucleotides are right, but since the T was added, it will mess up how the rest of the sequence is read. It will be read UAT GGC GAA... instead of UAG GCG AAU... see how it messed it up? This is an Insertion (Addition) Mutation.
c. the second nucleotide was deleted. This is called a Deletion Mutation. It will mess up the rest of the sequence, similar to how the example above did.
I hope that helped you understand!
Can someone help me understand this plz
i am thick and stiff
i have boxlike shape
i am found only in plants
i am what makes them to stand upright
Answer:
belt?
Explanation:
WILL MARK BRAINLIEST!
Answer:
Recessive
Explanation:
When there is a skipped generation, the trait must be RECESSIVE. For dominant trait, having 1 dominant allele will give you affected phenotype. It can never give a skipped generation.
Which neurotransmitter is a major regulator of mood and behavior and can be chemically altered using drugs like Prozac or Zoloft?
a) nitric oxide
b) substance P
c) norepinephrine
d) serotonin
e) acetylcholine
Explanation:
Serotonin is an inhibitory neurotransmitter that responsible for regulating the bodies mood and behavior in the central nervous system and affect the functions of the entire body. Prozac and Zoloft are antidepressants that help retain more serotonin neurotransmitters in neurons.
Answer:
d) serotonin
What enzyme is used to break down bacteria
Which of the following represents a step in the nitrogen cycle?
Answer:
In general, the nitrogen cycle has five steps:
Nitrification (NH3 to NO3-) Assimilation (Incorporation of NH3 and NO3- into biological tissues) Ammonification (organic nitrogen compounds to NH3) Denitrification
Explanation:
WAITING FOR YOUR RESPONSE
Nitrogen is "fixed" by plants
O True
O False
Answer:
i think it is false. because symbiotic soil microbes do that
One of the following causes Creutzfeldt - Jakob disease?
Answer:
is caused by an abnormal infectious protein in the brain called a prion. Proteins are molecules made up of amino acids that help the cells in our body function.
Explanation:
Representation of system or object such as charts or maps are
Answer:
graphical models
Explanation:
The number of neurotransmitter molecules located within a specific synaptic gap would most clearly be
reduced by
Answer:
The correct answer is - reuptake.
Explanation:
The process that reabsorbs the neurotransmitters known as reuptake which reduced the number of neurotransmitter molecules. Neurotransmitter transporter found on the outer membrane of the plasma membrane assists the process of reuptake by reabsorbing the neurotransmitter molecules from the specific synaptic gap. Neurotransmitters recycle by this process in order to reuse again after a time for the particular signal to last.
Thus, the correct answer is - reuptake.
How are astronomers able to determine what elements are found in other stars and galaxies?
Answer:
This type of study is called spectroscopy. The science of spectroscopy is quite sophisticated. From spectral lines astronomers can determine not only the element, but the temperature and density of that element in the star. The spectral line also can tell us about any magnetic field of the star.
Explanation:
True or False: Interphase takes up roughly 90% of the time it takes to undergo mitosis, about 23 hours.
Answer:
I believe that it is true.
Explanation:
Interphase does take up about 90 percent of the phases but it is about 22 hours of dividing the cells
Which organism is a producer?
mouse
snake
owl
grass
Answer:
Grass
Explanation:
since producer is the first thing in the food chain its grass
Answer:
It is grass Duh!
༼ つ ◕_◕ ༽つ
1. All living things have a limited lifespan.
True
False
Answer:
True
Explanation:
Humans have a life span of 60 - 80 years while trees have a life span 1000 - 2000 years, also rats , camels , mosquito, earthworm have a limited lifespan.
Label flower parts on it
Answer:
AntherFilamentStamenStigmaStyleOvaryPistilOvum/OvulePetalSepalWhich type of molecule is embedded throughout the phospholipid bilayer?
Answer:Integral proteins
Explanation:
Which activities cause environmental pollution in your locality.Write how you can help to avoid them
Answer:
Activities cause environmental pollution is AIR POLLUTION
Can avoid by:
•Conserve energy at home at work,everywhere.
•Use public transportation or walk whenever possible.
•Keep car, boat and other engines properly tuned.
•Mulch or compost leaves and yard waste.
•Consider using gas logs instead of wood.
The activities that cause environmental pollution in my locality are the excessive usage of vehicles that emits a huge amount of carbon, excessive utilization of polythenes, and no proper method of waste treatment.
What is Environmental pollution?Environmental pollution may be defined as any sort of unwanted contamination or impurities present in the atmosphere that is harmful and toxic to the health of each and every living organism. It is one of the most threatening problems for the whole world that affects the overall diversity of living entities and ecosystems.
You can avoid all the activities listed above by following mechanisms:
Increase the use of electric vehicles rather than petrol or diesel vehicles. Enhance the utilization of poly bags that are easily decomposable and cause less harm to the land and soil. Installations of some authorized and trusted mechanisms for waste treatment.Therefore, it is well described above.
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explain thourough what pollution is
Answer: Definition and models Contamination alludes to the presence of a substance or substances in the climate that is unsafe or harmful. The substances or poisons might be hurtful to human wellbeing, different creatures, and plants. When something hurtful enters the climate at a quicker rate than it tends to be scattered, there is contamination. or Contamination is that the presentation of hurtful materials into the climate. These unsafe materials are called toxins. Poisons might be normal, as volcanic debris. they'll even be made by human activity, similar to waste or overflow created by industrial facilities. Contaminations harm the norm of air, water, and land. Explanation: Both describe what pollution means I hope this helps you
A membrane attack complex is a protein grouping that Multiple Choice stimulates basophils to attack a multicellular parasite in the body. triggers phagocytosis of a target cell by a nearby macrophage or neutrophil. links a pathogen to a red blood cell so that it is carried to the liver or spleen. forms a channel in the target cell membrane that causes cytolysis.
Answer:
The correct answer is ''forms a channel in the target cell membrane that causes cytolysis.''
Explanation:
The membrane attack complex (MAC) has the essential effect of producing a notable osmotic imbalance in the microorganism that leads to its cytolysis (in Gram-negative bacteria it inserts into the outer membrane, favoring the entry of lysozyme, and in Gram-positive ones insert into the cytoplasmic membrane, destroying the electrochemical gradients). The lytic pathway corresponds to the final reactions of the complement system. It begins when the C5 convertase enzymes formed either in the classical pathway, MBL or the alternative, fix the factor C5 and fragment it into C5a (anaphylatoxin) that passes into the fluid medium and C5b, which binds non-covalently to C3b. The C5b fraction captures C6 and C7 from the fluid phase, forming a stable C5b67 complex with chemotaxic activity and membrane-binding capacity, which when joining the C8 fraction is cytolytic, and acquires the ability to interact with C9 molecules, forming the complex C5b6789. The C9 molecules then undergo conformational changes, enhance and accelerate the penetration of this membrane attack complex (MAC), giving rise to the formation of channels that allow the free exchange of sodium and water with the outside of the cell, causing the consequent osmotic lysis (cytolysis)of the attacked cell, since C9 is structurally homologous to perforin, a protein released by cytotoxic T lymphocytes and NK cells, and which is also responsible for the formation of pores in the membrane of the target cells.
The role of the institutional animal care and use committee (IACUC) of a research institution is to provide research animals with clean and healthy conditions in the laboratory. mediate the acquisition of animals by the institution's researchers. review all proposals for animal research to be sure the procedures to be used are appropriate and humane. review animal research proposals only to ensure that the proposed experiments are scientifically valid.
Answer:
review all proposals for animal research to be sure the procedures to be used are appropriate and humane.
Explanation:
The Institutional Animal Care and Use Committee (IACUC) is a federal committee responsible for approving and/or prohibiting the use of animal (nonhuman vertebrate) subjects for research, testing and teaching purposes, as well as the inspection of animal facilities. IACUC evaluates the institution's animal programs and procedures as described by the Office of Laboratory Animal Welfare (OLAW). This committee has the task to verify animal's well-being by minimizing pain and distress (for example, by ensuring the use of non-invasive methods when possible). Researchers/educators that use animals for research/teaching purposes must previously submit a written request defined by the IACUC's guidelines.
b) In what way does the endocrine system cause homeostasis? (1 point)
Will mark brainliest!!!
Which of the following is an example of stored energy?
a. A car rolling down a hill
b. A soccer ball sitting on top of a cabinet
c. A dog lying on the floor
d. None of the above
b hope u like it .plz like it .ok
Answer:
I believe it's B.
Explanation:
Because the ball is not moving and it's storing energy being on top of the cabinet. And it has more gravitational energy on it because of its position and stored energy.
How can you tell the difference
between a plant cell and animal cell?
Answer:
I hope it helps you a lot!
:P
Explanation:
Answer:
Animal cell has no cell wall but plant cell has cell wall made of cellulose
As atmospheric CO2 increases, the amount of CO2 dissolved in seawater is expected to increase as well. This produces more carbonic acid, which then dissociates into hydrogen ions and something else.
Answer:
(HCO3-) bicarbonate
Explanation:
what useful purpose is served by cell division in a multicellular organism : select all the correct answers.
A: to ensure that a cell does not become to large
B; To produce new cells during an organisms growth
C: To replace damaged cells and tissues
D: to ensure all cells remain undifferentiated
Answer:
c
Explanation:
the main reasons cells duplicate is so they can replace damaged cells and tissues
The following options are the useful purpose is served by cell division in a multicellular organism:
A. to ensure that a cell does not become too large B. To produce new cells during an organism's growth C. To replace damaged cells and tissuesMulticellular organisms are the organism that is formed by the complex organization of cells, tissues, or organs Whereas a single-cell organism is unicellular organisms.
Single-celled organisms use cell division only for reproduction.All multicellular organisms use cell division for growthAnther purpose of cell division in multicellular is to replace and repair cells and tissues.Cell division is a strictly controlled process as a failure of regulation can be life-threatening.In multicellular organism cell division takes place in sex cells as well as somatic cellsThus, the correct answer is options A, B, and C.
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wh is cell called the functional unit of life?
Answer:
because the cell is the smaller unit that has the properties of life
Explanation:
There are three basic principles/statements that are the basis of the unified cell theory, which was proposed by Matthias Schleiden and Theodor Schwann in 1838. All living organisms are composed of cells (first principle), whereby cells can be considered as the basic, structural and organizational units of all organisms (second principle). Moreover, new cells always arise from existing cells (third principle). In consequence, the cell is the smaller unit that has the properties of life in order to carry out all metabolic processes including reproduction, growth, development, etc.