Animal cells do not have cell walls because they do not need them. Cell walls, which are found in plant cells, maintain cell shape, almost as if each cell has its own exoskeleton. Animals do have a cell membrane though.
What are cell walls?A rigid layer of nonliving material that surrounds the cells of plants and some other organisms. A cell wall is made up of cellulose, pectin, glycoproteins, hemicellulose and lignin. It is the outer boundary of the cell, it encloses the cytoplasm and the organelles of the cells. In plants cells it is inside the cell wall.
Let's take a look at the options:The first one is a tree. A tree is a type of plant and all plants have cell walls and it provides turbidity and durability for the plant. Therefore, a tree has a cell wall eliminating it as a option.The second one is fungi. Fungi are a eukaryotic organism that is usually filamentous (forming a mycelium) and heterotrophic. Fungi have a cell wall made of chitin, a nitrogen containing polysaccharide (NO amino acids) called hyphae. Therefore, fungi have a cell wall eliminating it as a option.The third one is plants. As mentioned before, all plants have cell walls. But to explain more, plant cells are surrounded by a strong cell wall that can change as they grow. It is made of a mixture of polysaccharides cross-linked together, which can give properties like flexibility, strength, turgor and waterproofing. Therefore, plants have a cell wall eliminating it as a option.The last one is animals. Animal cells have a cell membrane instead of rigid walls like plant cells do and that is mainly so they can move. Rigid cell walls don’t move - plants don’t move very much and what movement they do have is very slow and gradual. Animals move constantly - skin has to stretch, muscles must contract and extend. So the cells have to allow for that, and the flexible cell membrane is how they do it. Therefore, the answer is option D.To learn more about cell functions, check out these links:
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Which one of the following human activities is the greatest threat to biodiversity?
A. Habitat destruction
B. Climate change
C. Introduced species
D. Pollution
E. Overharvesting
Answer:
Overharvesting
Explanation:
Too much harvest and planting causes the soil to wear down and be less useful.
Answer:
B) Climate Change
Explanation:
LOVE YOUU :)
Which of the following is an
important function of water as
a nutrient?
A. It provides fiber.
B. It helps build and repair muscles.
C. It surrounds our organs for protection.
D. It helps regulate the body's temperature.
Marshall made the following table to compare the functions of physical structures in plants and animals:
Function Animal Structure Plant Structure
Provides support for the organism Skeleton
Exoskeleton Stem
Reproductive organs Testes
Ovaries Stamen
Pistil
X Skin
Fur
Feathers Waxy Covering
Bark
Which of the following should replace X?
Protect the internal organs of the organism
Protect the organism from harsh conditions
Transports water throughout the organism
Involved in reproduction of the organism
Answer:
The answer is Pistil
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Explanation:
Those who have positive qualities are often judged more positively on their other qualities. please select the best answer from the choices provided t f
It is a true statement that; "those who have positive qualities are often judged more positively on their other qualities."
What are positive qualities?The term positive qualities refers to those qualities that are generally perceived as being acceptable such as kindness towards other people. It is normal to love people because of their good qualities.
It is a true statement that; "those who have positive qualities are often judged more positively on their other qualities."
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Answer:
true
Explanation:
correct on edge
Heat from inside the earth is referred to as ______.
A) biomass
B) ethanol
C) geothermal
D) geyser
E) peat
Answer:C) geothermal
Hope this helps
Nick is smiling even though he does not feel happy. After a short time he feels happier. The best explanation for Nick's change in mood is
O bottom-up processing
o facial feedback
selective encoding
O justification of effort
o facial feedback
When someone replicates a emotion, they tend to feel it
Nick is smiling even though he does not feel happy and after a short time he feels happier too. This change in mood is due to facial feedback. Therefore, the correct statement is option B.
What is the facial feedback mechanism?Facial feedback is a psychological theory that suggests that the expression on a face of a person can influence their emotions and mood also. Therefore, when a person smiles even when they are not feeling happy, it can trigger positive emotions in the brain that change in mood.
Nick is smiling even though he is not feeling happy. Therefore, this act of smiling can trigger positive emotions in his brain and changes his mood because of the facial feedback mechanism.
However, bottom-up processing is the processing of sensory information from the environment to create a perception, while selective encoding is a process of selectively attending to and encoding certain aspects of a stimulus while ignoring others.
Therefore, Nick is smiling even though he does not feel happy and feels happy after a short time due to facial feedback.
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23. Power equals
A.Speed plus endurance
B. Strength times speed
C. Speed times velocity
Neither, power= energy/time
A fired worker who fakes mental harassment by his boss in order to explain his unfair treatment
o is insane
o is malingering
o is psychotic
o has a mental illness
Can someone please help !
How might human population growth result in a tragedy of the commons?
A. Each birth is a common resource for the population.
B. All people use natural resources to survive.
C. People are the most important resource on Earth.
D. People have more in common than they realize.
Answer:
B: all people use natural resources to survive.
Explanation:
During what stage of development do cells
differentiate?
A. at fertilization
B. once birthed
C. as a zygote
Answer:
at fertilization
Explanation:
The brain is an organ in the nervous system.
Which of the following is true about the brain?
Choose 1 answer:
(A) the brain is made up of a single type of tissue.
(B) the brain is made up of different tissues that carry out the same function.
(C) the brain is made up of tissues with different functions that work together.
Answer:
C
Explanation: the brain is made up of tissues with different functions that work together.
The brain is an organ in the nervous system, so the statement that is true about the brain is that the brain is made up of tissues with different functions that work together, which is in option C.
What is the function of the brain as a part of the central nervous system?The brain is a part of the central nervous system, and it is one of the most complex organs in the body which is responsible for coordinating and controlling body functions such as movement, sensation, thought, etc. by receiving and interpreting information from the senses and generating responses to that information.
Hence, the brain is an organ in the nervous system, so the statement that is true about the brain is that the brain is made up of tissues with different functions that work together, which is in option C.
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State similarities and differences between the laboratory thermometer and the clinical thermometer
Answer:
Its simple
Explanation:
Answer: Similarities Both thermometers are used to measure temperature and both of them use mercury. Differences Clinical thermometer is used to measure human body temperature whereas laboratory thermometer is used to measure temperature of other object which has higher temperature than human body temperature.
Describe at least one trait you used to make this classification.
Answer:
genetics and hereditary inheritance
Which are correct examples of physical (P), chemical (C), and biological (B) barriers? P: complement system; C: saliva; B: coughing P: coughing; C: saliva; B: complement system P: coughing; C: sneezing; B: complement system P: complement system; C: saliva; B: sneezing
The correct examples of physical (P), chemical (C), and biological (B) barriers is P: coughing; C: saliva; B: complement system.
What are barriers?Barriers are the immune defence mechanisms used by the body to prevent the invasion of microorganisms from causing harm.
Examples of immune barriers include:
Physical barrier: Example is coughingChemical barrier: Example is salivaBiological barrier: complement system.Learn more about immune system here:
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how many chromosomes are in the daughter cells after meiosis is completed?
Answer:
23 chromosomes
Explanation:
Each daughter cell will have half of the original 46 chromosomes, or 23 chromosomes. Each chromosome consists of 2 sister chromatids. The daughter cells now move in to the third and final phase of meiosis: meiosis II.
Answer:23. Just take half of 46 away and there's your answer.
Explanation:
Which scientist argued that the mind and body were completely separate entities?
Question 14 options:
Walter Cannon
Descartes
Kurt Lewin
Hans Seyle
Answer:
Walter Cannon
Explanation:
as he came up with the theory on how to separate the mind and body
The blind mole rat is a close relative of other rats. however, mole rats live underground for their entire lives. as a result, their eyes have evolved into useless structures. presumably, mole rats will not have eyes at all in the distant future. what type of structures are the mole rats eyes?
a.
vestigial structure
b.
developmental structure
c.
homologous structure
d.
analogous structure
Answer:
A. vestigial structures
Explanation:
Vestigial structures are those that serve no purpose in current organisms, but were useful to ancestors of those organisms.
Can you please give some example's of endangered animal's ? :<
Answer:
axolotls and other few species of fish
giant panda (Ailuropoda melanoleuca) ...
tiger (Panthera tigris) ...
whooping crane (Grus americana) ...
blue whale (Balaenoptera musculus) ...
Asian elephant (Elephas maximus) ...
sea otter (Enhydra lutris) ...
snow leopard (Panthera uncia) ...
gorilla (Gorilla beringei andGorilla gorilla)
1. Define mass defect.
Answer:
the difference between the mass of an isotope and its mass number.
Explanation:
why photosynthesis is known as the pathway for energy
Answer:
Photosynthesis is important to living organisms because it is the number one source of oxygen in the atmosphere. Without photosynthesis, the carbon cycle could not occur, oxygen-requiring life would not survive and plants would die. It transforms light to chemical energy.
that's why it's called the pathway to energy.
Explanation:
hope it helps...
13. Which method for producing electricity has had the most negative impact on the
atmosphere?
A burning fossil fuels
B. controlling nuclear fission
C. harnessing wind with windmill farms
D. using hydroelectric dams to block rivers
Helpppp please
Answer:
The answer is A.
Explanation:
One of the downsides to electricity is the way it is generated. Usually, electricity was generated through Coal which as a fossil fuel was pivotal in releasing large amounts of carbon dioxide into the atmosphere.The method for producing electricity that has had the most negative impact on the atmosphere is A) burning fossil fuels.
What is the consequence of burning fossil fuels ?Burning fossil fuels, such as coal, oil, and natural gas, releases large amounts of carbon dioxide and other greenhouse gases into the atmosphere. These gases trap heat in the Earth's atmosphere, leading to global warming and climate change.
In addition, burning fossil fuels also releases other pollutants, such as sulfur dioxide and nitrogen oxides, which can contribute to acid rain and other environmental problems.
While all methods of producing electricity have some impact on the atmosphere, burning fossil fuels has had the most negative impact due to the sheer amount of greenhouse gases and other pollutants that are released during the process.
While there are efforts to reduce the negative impacts of burning fossil fuels, such as developing cleaner burning technologies and transitioning to renewable energy sources, the continued use of fossil fuels for electricity generation remains a significant challenge for addressing climate change and reducing air pollution.
In addition to greenhouse gas emissions, burning fossil fuels also produces other pollutants, such as sulfur dioxide and nitrogen oxides, which can contribute to acid rain and other environmental problems.
Therefore, extraction, transportation, and storage of fossil fuels can also have negative environmental impacts, such as oil spills, groundwater pollution, and habitat destruction.
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2. Explain how the distribution and availability of resources might influence population density?
Answer:
The availability of natural resources encourages a higher population density as these can be processed and used in industry and manufacturing. Regions that experience no or few natural disasters are more likely to have a lower population density as they are safer.
Which structure allows the diaphysis of the bone to increase in length until early childhood?.
Answer:
Epiphyseal Plate
Explanation:
Insulin, a nonsteroid hormone, binds with a cell membrane receptor causing activation of proteins inside the cell. What would you consider insulin to be in this example
We consider insulin to be Protein activator because it is responsible for the activation of protein inside the cell.
What is activator?Activators are those molecules that bind themselves to a substance and increase their activity. These molecules are the opposite of inhibitors that prevent a substance from doing its function.
So we can conclude that we consider insulin to be Protein activator because it is responsible for the activation of protein inside the cell.
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Suppose that somite stem cells commit to their cell fates by three days post fertilization. Which result would be MOST likely in the chick embryos receiving somites transplanted in the reverse order
The organs arising from quail somites develop in the reverse order because transcriptional programs activated in the nucleus can't be reversed.
What is a Nucleus?This is referred to as the part of the cell which is membrane bound and contains chromosomes.
The fate of the chick embryos receiving somites transplanted in the reverse order is mentioned above.
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3. A cell with 10 chromosomes undergoes mitosis.
(b) How many chromosomes does each daughter cell have?
Answer:
In a cell with 10 chromosomes undergoes mitosis, the result are 2 daughter cells each with 10 chromosomes
Explanation:
Cells have the ability to reproduce or replicate through 2 processes:
Mitosis
Meiosis
Mitosis differs from meiosis because the final result is always
2 daughter cells
The daughter cells are identical to the mother cell and this includes the same number of chromosomes
This means in mitosis 1 cell with 10 chromosomes leads to two identical cells each with 10 chromosomes.
The graph below shows the number of occupied
bald eagle nesting in North America between
1960 and 2007.
Which human activity most likely had the greatest
influence on the trends shown in the graph?
A. Breeding eagles in captivity
B. Allowing the hunting of eagle predators in
national forests
C. Releasing eagles into North American forests
from other continents
D.Conservation efforts, including a ban on
certain pesticides
Answer:
This is just a guess because I can't see the graph, but I think the answer is B. Don't use this though, as it's only a guess.
Explanation:
IS a catfish a producer, consumer, or decomposer?
Answer:
Scavengers include vultures and catfish. Some consumers are also decomposers. Decomposers break down dead plants and animals. The two main kinds of decomposers are bacteria and fungi.Explanation:
If a researcher tried shotgun sequencing with a single chromosome from a single cell, would the process work?.
Answer: No, there would be no overlap because there is only one piece of double-stranded DNA that is fragmented.
Explanation: