Explanation:
The cell theory, or cell doctrine, states that all organisms are composed of similar units of organization, called cells. The concept was formally articulated in 1839 by Schleiden & Schwann and has remained as the foundation of modern biology. The idea predates other great paradigms of biology including Darwin’s theory of evolution (1859), Mendel’s laws of inheritance (1865), and the establishment of comparative biochemistry (1940).
First Cells Seen in Cork
While the invention of the telescope made the Cosmos accessible to human observation, the microsope opened up smaller worlds, showing what living forms were composed of. The cell was first discovered and named by Robert Hooke in 1665. He remarked that it looked strangely similar to cellula or small rooms which monks inhabited, thus deriving the name. However what Hooke actually saw was the dead cell walls of plant cells (cork) as it appeared under the microscope. Hooke’s description of these cells was published in Micrographia. The cell walls observed by Hooke gave no indication of the nucleus and other organelles found in most living cells. The first man to witness a live cell under a microscope was Anton van Leeuwenhoek, who in 1674 described the algae Spirogyra. Van Leeuwenhoek probably also saw bacteria
The cell theory, states that all organisms are composed of similar units of organization, called cells.
What is cell theory?The concept of cell theory was in 1839 by Schleiden & Schwann which leads the foundation of modern biology. Cell theory states that every cell is generated from another preexisting cell.
This idea makes the great revolution in biology including Darwin’s theory of evolution (1859), Mendel’s laws of inheritance (1865), and the establishment of comparative biochemistry (1940).
Schleiden & Schwann propose every organism is composed of the cell, which is the basic unit of life and each cell comes from the preexisting cell, and each cell produces a progeny which is similar to its parent cell.
Therefore, cell theory states the existence of the cell in the organism.
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Please help for the 4 and 5 question in the picture above.The person answering both part of question 4 and 5 will be marked as brainliest. I promise.The subject is hindi but there is no option so I opted for biology.but pls help.
Answer:Am really sorry...I wanted to help you but I cannot understand Hindi
Explanation:
I really hope you get an answer
1.What factors define aquatic ecosystems?
Answer:
In other words, physical or chemical parts of the environment that affect the organisms that are in that environment.
Explanation:
For aquatic ecosystems, these factors include light levels, water flow rate, temperature, dissolved oxygen, acidity (pH), salinity and depth. Light level is an important factor in aquatic ecosystems. hope this helps you :) god loves you :)
Light level is an important factor in aquatic ecosystems.
The physical or chemical parts of the environment that affect the organisms that are in that environment.
What is aquatic ecosystem?An aquatic ecosystem is a water-based environment. Abiotic factors are the non-living components that form the environment in which organisms subsist in a current.
The main abiotic factors in the marine environment are as; light, temperature, salinity, and hydrostatic pressure. dissolved oxygen, acidity (pH), salinity and depth.
Here Without pollution or acid rain, most lakes and streams would have a pH level of around 6.5.
Therefore Light level is an important factor in aquatic ecosystems.
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In humans, the quadriceps muscle is a skeletal leg muscle under voluntary control. As such, it contracts in response to signals from the motor cortex in the cerebrum. If such a muscle contracts involuntarily, that indicates:
Answer:
The correct answer is - operation of reflex arc.
Explanation:
The reflex arc is a unique and special type of neural pathway that starts with a sensory neuron and ends with a motor neuron. In this operation sensory neuron acts as the receptor and motor neuron is effector. This type of neural circuit helps in faster response.
Voluntary muscles like quadriceps muscle are normally in control voluntarily however, such muscle may contract involuntary due to reflex arc. This type of contraction takes place before the signal has even reached the brain.
In this response the sensory neuron takes the signal to the spinal cord and then motor neuron to the effector muscle for faster response.
Thus, the correct answer is - operation of reflex arc.
choose one plant or animal and what are the 3 adaptions this organisms has
Antibodies:_______. A. play a large role in cell-mediated immunity. B. are produced by both T and B cells. C. are composed of four light and four heavy polypeptide chains. D. are not specific, but act generally. E. have a variable region that binds to a specific antigenic determinant.
Answer:
E. have a variable region that binds to a specific antigenic determinant.
Antibodies E. have a variable region that binds to a specific antigenic determinant.
What is the region of the antibody that the antigen binds to?This location of the antibody is known as the Fab (fragment, antigen binding) place. it's far composed of 1 constant and one variable domain from every heavy and light chain of the antibody. The paratope is shaped on the amino terminal cease of the antibody monomer by the variable domains from the heavy and light chains.
What binds to an antigenic determinant?An antigenic determinant is a website online of an antigen molecule that is termed an epitope and interacts with the unique antigen-binding site within the variable vicinity of an antibody molecule called a paratope.
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An organism is _______ for a gene if it has two copies of the same allele for the gene.
The genotype of an organism and the interaction of the genotype with the environment determine the organism’s _______, or observable characteristics.
The law of independent assortment states that the separation of alleles for one gene are independent of that of other genes, unless the genes are _______.
Mendel’s law of _______ governs which allele is expressed in an individual.
Respond to the following based on your reading.
In the previous section, you learned that the allele for brown eyes (B) is dominant, and blue (b) and green eyes (g) are recessive, while green eyes are dominant over blue eyes. What eye color would someone with the following genotypes exhibit? (a) BB, (b) Bb, (c) gb, (d) Bg, (e) bb.
Discuss the law of segregation and explain why each organism has two copies of the gene for each trait expressed.
What type of experiments did Mendel conduct, and what did he want to find out about the heritability of the seven traits he chose to study?
Answer:
1. Purebred (N.B: the exact word is considered a foul word)
2. Phenotype
3. Linked
4. Segregation
5) (a) BB- Brown eyes
(b) Bb- brown eyes
(c) gb- green eyes
(d) Bg- brown eyes
(e) bb- blue eyes
The other questions are explained below
Explanation:
1. A purebred organism is that which possess two copies of the same alleles in its genotype. An allele is a contrasting form of a gene. If the two alleles are the same, the organism is said to be purebred.
2. Phenotype of an organism is the observable characteristics of the organism. It is determined by the organism's genotype in interaction with its environment.
3. Mendel's law of independent assortment states that the alleles of a gene will separate into gametes independently of another gene unless the genes are linked. Linked genes are genes that are too close to each other on a chromosome and hence, do not sort independently. They're rather inherited together.
4. Mendel’s law of Segregation governs which allele is expressed in an individual. According to this law, an organism will express the allele it randomly receives from each parent. If an organism receives two different alleles, it will express the allele that is dominant. In other words, an organism will only express the recessive trait if it receives two recessive alleles from both parents.
5. a) BB- Brown eyes because the organism is purebred for the dominant (brown) allele
(b) Bb- brown eyes because the brown allele (B) will mask the expression of blue allele (b) and express itself.
(c) gb- green eyes because the allele for green eyes (g) is dominant over the allele for blue eyes.
(d) Bg- brown eyes because the brown allele (B) is dominant over the allele for green eyes (g), hence, it will mask its expression
(e) bb- blue eyes because the organism is purebred for the blue allele i.e. same recessive (blue) alleles in the gene.
6. The law of segregation as proposed by Mendel states that the alleles of a gene will separate into gametes during gamete formation (meiosis). This is done in such a way that each gamete contains only one allele of each gene. Hence, an organisms will contain two copies of a gene because they receive each copy (allele) from each parent during fusion of their gametes.
7. Mendel conducted an hybridization experiment i.e. a cross involving two individuals that possess different traits. He did this in order to find out how different traits/characteristics in organisms were transferred from one generation to another. Mendel chose the pea plant for his experiment because they could easily be manipulated for self and cross pollination. Mendel studied seven (7) different traits or characteristics in pea plants including height, seed shape, seed color, flower color etc.
30 POINTS PLZ HELP I WILL GIVE BRAINLIEST Identify and describe the two main methods for measuring the age of Earth and its parts.
Answer:
Radiation Measurement.
Stratigraphic Superposition.
The Fossil Record.
Explanation:
Answer:
Radiation Measurement.
Stratigraphic Superposition.
The Fossil Record.
Explanation:
an example of biogeochemical cycle would be the A. carbon cycle B. fire cycle C. trophic cycle
Answer:
Carbon Cycle
Explanation:
Which of the following is composed of a population of a species plus populations of other species? A. Community B. Biotic Potential C. Abiotic community D. Ecosystem
A Community is composed of a population of a species plus populations of other species. Thus, the correct option is A.
What is Population?A Population may be defined as a group of individuals belonging to the same species living in the same area at a given time. Some demographic characteristics of a population are size, density, birth rate, death rate, population dispersal, etc.
A community may be defined as a group of individuals belonging to different species living in the same area at a given time.
An ecosystem may be defined as a place or area where individuals of different species along with abiotic factors live together and interact with one another for the purpose of food, shelter, and space.
The Abiotic community deals with the existence of abiotic factors like temperature, rainfall, fire, winds, mountains, hills, etc.
Therefore, a Community is composed of a population of a species plus populations of other species. Thus, the correct option is A.
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please give the correct answer to this question
Answer: Lymphatic system
Explanation:
Not respiratory and excretory for sure.
Not nervous because the diagram doesn't show spinal nerves clearly. So its lymphatic system.
:-)
What do you think that David would have predicted
based on his hypothesis? (Set it up as an IF
THEN statement)
Answer:
Hey there!
I believe that David's prediction would be: If the amount of pollutants in the atmosphere reached an amount unhealthy for the salamanders, then the salamander population would decrease.
Let me know if this helps :)
why does people have sex?
Answer:
for the continuation of species.. further it's as needy as a person take the meal
Explanation:
It's can be counted as a daily need of people as we take the meal
En la raza de ovejas Rommey Marsh, un gen conocido como gris letal, provoca que el feto gris GG, muera antes de las 15 semanas de gestación; El Genotipo heterocigótico Gg produce lana gris y el genotipo homocigótico gg produce lana negra. Si se cruzan individuos heterocigóticos. Cuáles serán las proporciones fenotípicas esperadas en la progenie viva? *
Answer
1:2:1
Please check the file,due to technical reasons there was issues with submission
Explanation:
please help!!
What are some factors that influence emotional changes throughout adolescence?
Answer:
Explanation:
Some of the factors that influence emotional changes during adolescence include, among others, changes in self-perception, changes in the way teens are treated, increased sensitivity to criticism, increased desire for independence, and an increased need to belong.
answer answer answer answer
Answer: C
Explanation: Amoeba use pseudopods to move around and people use feet to move.
Answer:
The answer is C
Compare the characteristics of nitrogen fertilisers that are used for
broadcasting with a phosphate fertiliser that is insoluble in water??
Answer:
Nitrogen is mobile while phosphorus is immobile in the soil.
Explanation:
Nitrogen fertilizers are those fertilizers which provide nitrogen to the plants that is required by plants for the formation of amino acids. It increases vegetative growth of plant. Nitrogen fertilizer is highly mobile due to soluble in water and contaminated the underground water by leaching while phosphorus fertilizer are those fertilizer which provide second macro-nutrient i. e. phosphorus to the plants. Phosphorus is a vital component of energy molecule such as ATP. It is insoluble in water so it is immobile. Only 20 % of the applied phosphorus fertilizer is available to plants.
please answer the question
Answer:
two of the DNA fingerprint are same when they contain the same nitrogenous bases in the same location of the DNA.
Explanation:
The DNA fingerprint is one of the most important tool as a forensic medicine expert to to form such condition and rule it out to come to a diagnosis.
DNA fingerprint uses the base pair which a different for all the other human beings. Due to this from the blood or other cells of the body there can be an evidence of the person and this is usually done on a comparative basis.
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Arctic sea ice has declined over the past few decades causing water levels to increase. This is an interaction of which two spheres?
Answer:
Cryosphere and Hydrosphere
Explanation:
The Cryosphere refers to the frozen water bodies on earth. This includes glaciers, icebergs, ice sheets and frozen water surrounding the Arctic and Antarctica.
The Hydrosphere refers to all the water bodies on Earth, including rivers, streams, lakes, and ponds.
Answer:
Cryosphere and Hydrosphere
Explanation:
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why is it necessary yo separate oxgynated and deoxgynated blood in livng oranisum
Explanation:
it is necessary in mammals and birds to separate oxygenated and deoxygenated blood because this makes their circulatory system more efficient and helps in maintaining a constant body temperature
For each of the following types of transcriptional control, indicate whether the protein produced by the regulator gene will be synthesized initially as an active repressor, inactive repressor, active activator, or inactive activator.a. Negative control in a repressible operonb.b. Positive control in a repressible operonc.c. Negative control in an inducible operond.d. Positive control in an inducible operon
Answer:
The type of protein synthesized for each case of transcriptional control is given below:
a. Negative control in a repressible operon
Inactive repressor
b. Positive control in a repressible operon
Active activator
c. Negative control in an inducible operon
Active repressor
d. Positive control in an inducible operon
Inactive activator
Explanation:
Different types of operons exist in different bacterial systems and they control the transcription of genes by means of regulator proteins. These proteins are responsible for turning on or off the gene encoding a particuar protein depending on whether or not the cell requires for it.
what are top consumer
Answer:
it is a food chain.
I can't write more it's not allowed
11. By what process do streams and rivers move material?
O infiltration
O mass wasting
O erosion
O weathering
Erosion is the process by which Earth's surface is worn away by the action of water, wind, ice, or gravity. Hence option C is correct.
Streams and rivers are agents of erosion, and they move material by a variety of processes, including:
Dissolution - The water in a stream can dissolve minerals from the rocks and soil that it flows over.
Suspension - Fine particles of sediment can be suspended in the water and carried downstream.
Traction - Larger particles of sediment can be rolled or bounced along the bottom of the stream.
Saltation - Small pebbles and stones can be bounced along the bottom of the stream.
The type of erosion that a stream or river causes depends on the size of the particles that it is carrying. Streams and rivers that carry a lot of fine sediment are called suspended-load streams. Streams and rivers that carry a lot of large particles are called bed-load streams.
Erosion by streams and rivers can have a significant impact on the landscape. It can create valleys, canyons, and deltas. It can also transport sediment to other areas, where it can be deposited and form new landforms.
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A scientist thinks that a certain chemical is a mutagen. She exposes plant cells to a large amount of this chemical in the laboratory. Which statement best provides evidence that the substance is a mutagen? -The cells die within hours of being exposed to the chemical. -The cells grow more quickly than those that were not exposed to the chemical. -The cells change after being exposed to the chemical, and this change is passed to the next generation of cells. -The cells continue to divide at the same rate as before they were exposed to the chemical.
Answer:
The cells change after being exposed to the chemical, and this change is passed to the next generation of cells.
Explanation:
Mutation is a process that occurs from time to time to the genetic material of living cells. Mutation is a change in the nucleotide sequence of a DNA or gene. It is usually caused by errors during replication or induced by an external substance called MUTAGEN.
A mutagen is any substance that causes mutation in an organism. Hence, according to the question, the chemical substance which is thought to be a mutagen will change the cells after being exposed to the chemical, and this change is passed to the next generation of cells.
N.B: Since mutation affects the gene, it is passed on to the offsprings during reproduction.
Answer:
its c did the test
Explanation:
2 Describe why it would be an advantage for the seeds to be able to grow at any angle
Answer:
Seed grow at any angle is good for the plant because the barrier did not stop the plant growth.
Explanation:
If we planted a seed in the soil and there is any barrier such as stone or brick etc inside the soil so the roots change its direction because the seed grows at any angle. The shoot that emerge from the seed grow in upward direction if the stem is strong but some plants also grow horizontally due to weak stem so it is not compulsory for the plant to grow in only one direction, it grows whatever they want.
What is biology??And what does it came from??
Answer:
BIOLOGY IS THE STUDY OF LIFE
Explanation:
Answer:
Biology is studying about life and the human body. The term biology in its modern sense appears to have been introduced independently by Thomas Beddoes (in 1799)
Hope this helps!
How does the use of hydroelectric energy compare to the use of coal?
a.
Hydroelectric energy is more commonly used than coal.
b.
Hydroelectric energy is associated with less waste production than coal.
c.
Hydroelectric energy has a larger environmental impact than coal use.
d.
Hydroelectric energy requires more land space than coal use.
Currently, Coal is widely used because it's cheaper.
hydroelectric energy is more expensive (to build) but it has much much less waste, and no carbon emissions unlike coal
rest options are false.
Answer:
B.) Hydroelectric energy is associated with less waste production than coal.
Explanation:
While coal produces ash, CO2, CO, NOx, SOx, and many other waste products, hydroelectric energy has no waste products and doesn't pollute the environment.
The notion that the traits that help a species survive and reproduce are passed along more frequently than those that do not (i.e. differential reproduction and adaptation) is known as
Answer:
Natural selection
Explanation:
According to Darwin's theory, natural selection is the process by which individuals better adapted to their environments have more chances to survive and reproduce, and thereby their descendants will be better represented in the next generation. This mechanism exploits the existence of natural variation among members in the population which is used to select those individuals that are better adapted (i.e., with a higher adaptive fitness) for their environments. Natural selection is a key mechanism of evolution by which species change across time.
Analogies are often used to help make concepts easier to understand. Trisha wants to write an analogy to help her remember the difference between the axial skeleton and the appendicular skeleton. Which is the best analogy? ~The axial skeleton is like the skin of an apple; the appendicular skeleton is like the core of an apple. ~The axial skeleton is like the core of an apple; the appendicular skeleton is like the skin of an apple. ~The axial skeleton is like the frame of a swing set; the appendicular skeleton is like the swings. ~The axial skeleton is like the swings on a swing set; the appendicular skeleton is like the frame of a swing set.
Answer:
The correct answer is - The axial skeleton is like the frame of a swing set; the appendicular skeleton is like the swings.
Explanation:
The axial skeleton is the part of the human skeleton system that supports and protects vital organs of the body and makes a frame for the body structure that include bones of skull, trunk rib cage and ribs. The axial skeleton system is like a frame of a swing set that holds the swings and provide support to the swings.
On the other hand, The appendicular skeleton is like the swings of the of the swing set that can move and provide motion to the body, upper body limb, shoulder girdle and lower limb and pelvic girdle are the bones of appendicular skeleton.
Thus, the correct answer is - The axial skeleton is like the frame of a swing set; the appendicular skeleton is like the swings.
Answer:
C - Axial skeleton is like the frame of a swing set
Explanation:
Explain how Darwin’s theory of evolution by natural selection may have led to all giraffes having long necks.
Answer:
Because this individual had a longer neck, it was able to reach food sources that other animals couldn't...
how does the cell wall contributes towards maintaining homeostasis in the cell
Answer:
The water wants to flow from the higher concentration, which is outside of the cell, to the lower concentration, which is inside of the cell. The cell membrane helps to regulate and slow down the flow of water into the cell. This is yet another way that the cell membrane helps maintain homeostasis.
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