Answer:
Option-D
Explanation:
Plasmodesmata are the plasma membrane lined pores present in the cells of the plants. Inside these pores runs a closed tubelike structure which is an extension of the endoplasmic reticulum.
The plasmodesmata allows cell to cell communication which involves symplast mode of transport that is through its cytoplasm.
The small water soluble molecules like amino acid and sugars can easily pass through these plasmodesmata via diffusion. The large molecules can be transported through these plamodesmata through selective diffusion.
Thus, Option-D is the correct answer.
An explanation of how plant cells communicate across cell walls will most likely refer to the diffusion through plasmodesmata is Small, water-soluble molecules.
Small water soluble molecules often cross the membrane through the process of Diffusion. It is known as passive transport due to the fact that no external energy is used.
Polar molecules, such as water and small water-soluble molecules example urea, chloride ions, sodium ions etc. often
diffuse across membranes through the water-filled channels formed by membrane proteins.
Plasmodesmata are refered to ad connections through which cells communicate chemically with one another via their thick walls.
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A homozygous tomato plant with red fruit and yellow flowers was crossed with a homozygous tomato plant with golden fruit and white flowers. The F1 all had red fruit and yellow flowers. The F1 were testcrossed by crossing them to homozygous recessive individuals and the following offspring were obtained:Red fruit and yellow flowers - 41
Red fruit and white flowers - 7
Golden fruit and yellow flowers - 8
Golden fruit and white flowers - 44
How many map units separate these genes?
A) 17.6
B) 15
C) 17.1
D) 18.1
Answer:
I think it's A correct me if am wrong am not that smart am sorry if am wrong
In garden peas, the axial (A) flower position is completely dominant to the terminal (a) flower position. You cross a true-breeding axial flowering plant to a true-breeding terminal flowering plant. What is the genotype of the true-breeding axial flowering plant?
Answer:
AA
Explanation:
A true breeding organism for a particular trait is an organism that would produce progeny with the same trait whe self fertilized.
Hence, since axial flower is represented by the allele A, a true breeding flowering plant will have the genotype AA.
Axial flower (A) is dominant over terminal flower (a).
True-breeding axial flowering plant will have the genotype AA.
True breeding terminal flowering plant will have the genotype aa.
AA is crossed with aa.
AA x aa
offspring: Aa, Aa, Aa and Aa.
All the offspring will exhibit axial flowering.
What are some benefits to producing Super Cows?
Answer:
Genetically modified cows produce 'human' milk.
Explanation:
Which process must occur for a muscle to be able to relax
Answer: The concentration of calcium in the myofibril must decrease.
Explanation:s soon as the stimulus which causes myofibril to contract stops, its time for muscle to relax.
A low calcium level in the protoplasm is the utmost requirement of muscle relaxation otherwise sliding of myosin will continue and muscle will keep on showing contraction. In order for muscle contraction, calcium ion i.e. Ca²⁺ must come out of the protoplasmic reticulum so for relaxation reverse process occurs i.e. Ca²⁺ is pushed back to the protoplasmic reticulum. There are many pumps known as "calcium pumps" which facilitate this process. Now, the concentration of Ca²⁺ becomes comparatively low in the protoplasm which causes troponin C to detach from Ca²⁺. Their detachment causes actin and myosin to detach from each other too which finally leads to muscle relaxation.
The defining characteristics of active transport are that this category of transport moves substances _________ their concentration gradient and requires ___________.
Answer:
Against; energy.Explanation:
1. Active transport is the transport of molecules, in that the particles move across a membrane from a region of lower concentration to a the region of higher concentration with the help of energy.
2. Active transport is the energy-requiring process and results in the transportation of molecules and ions across membrane against a gradient called uphill transport.
3. Example: The Sodium-Potassium pump.
The chief force pushing water and solutes out of the blood across the filtration membrane is A) the ionic electrochemical gradient B) protein-regulated diffusion C) glomerular hydrostatic pressure D) the size of the pores in the basement membrane of the capillaries
Explanation:
Glomerular filtration is the process which kidneys uses to filter excess fluid and waste products out of the blood into the urine collecting tubules of the kidney, so that they may be eliminated from the bodyThe rate at which kidneys filter blood is called the glomerular filtration rateThe main driving force for the filtering process, or outward pressure is the blood pressure as it enters the glomerulus, this is counteracted to some extent by inward pressure due to the hydrostatic pressure of the fluid within the urinary space, and the pressure generated by the proteins left in the capillaries that tend to pull water back into the circulatory system (colloidal osmotic pressure)The net filtration pressure is the outward pressure minus the inward pressureEthidium bromide is a common intercalating agent used to visualize DNA in electrophoresis gels by associating with the DNA in the gels and fluorescing under UV light to reveal bands. How does ethidium bromide associate with the DNA?
Answer:
EtBr inserts between the stacked bases in the DNA double helix.
Explanation:
EtBr is used for visualizing DNA bands as it fluoresces under the UV illumination. EtBr is an aromatic compound that is capable of inserting itself between the stacked bases of the DNA double helix. The hydrophobic environment around the base pairs where the EtBr intercalates is responsible for the fluorescence. As the EtBr molecule intercalates between these base pairs the cation of EtBr sheds the water molecules associated with it and this causes it to fluoresce under UV light as water is a quencher of fluorescence.Why do you think the left atrium and left ventricle are shown on the right side of the diagram?
Answer: Because the heart model is always in anatomical position. It is always based on the patient.
The left atrium and left ventricle are shown on the right side of the diagram because it is a frontal section of the heart, which presents the heart as if it were cut in half from front to back.
Explanation:The left atrium and left ventricle are shown on the right side of the diagram because the diagram is a frontal section of the heart, which means it shows the heart as if it were cut in half from front to back. In this view, the left side of the heart is on the right side of the diagram and vice versa.
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In the first minute of her talk, Earle lists several ways the oceans have changed in the past 50 years because of human impact. What are some of these ways?
Answer:
She mentions that more than ninety percent of the big fish in the ocean have been fished and eaten. That almost half of the coral reefs are dying and disappearing. She also mentions how oxygen levels are decreasing causing the ecosystem and wildlife to die.
*WARNING*
Do not copy this word for word as you'll be caught for plagarism!
Explanation:
The first minute of the talk:
"I want to share with you my personal view of changes in the sea that affect all of us, and to consider why it matters that in 50 years, we've lost -- actually, we've taken, we've eaten -- more than 90 percent of the big fish in the sea; why you should care that nearly half of the coral reefs have disappeared; why a mysterious depletion of oxygen in large areas of the Pacific should concern not only the creatures that are dying, but it really should concern you. It does concern you, as well."
Final answer:
Human activities over the past 50 years have led to significant changes in the oceans, including sea-level rise, decrease in fish populations, ocean acidification, introduction of non-native species, and pollution and habitat destruction.
Explanation:
Human Impacts on the Oceans
In the past 50 years, human activities have significantly altered the oceans. Some of the changes include:
Sea-level Change: Due to climate change, sea levels have been rising, affecting coastal processes and habitats like salt marshes.Decrease in Fish Populations: Overfishing and changes in marine ecosystems have led to large decreases in the abundance of fish.Ocean Acidification: The increase in carbon dioxide emissions has resulted in acidification of oceans, affecting marine life with calcium carbonate shells.Introduction of Non-native Species: Global commerce and other human activities have introduced thousands of invasive species, causing ecological and economic harm.Pollution and Habitat Destruction: Activities such as bottom trawl fishing, coastal development, and aquaculture have damaged marine habitats and contributed to pollution.These are just a few examples of the human impacts on ocean ecosystems, illustrating the urgent need for conservation and sustainable management of ocean resources.
Why can't viruses effect non-livng things?
Answer:they need an active host
Explanation:
Answer:
Viruses need a host to survive.
Explanation:
They are categorized under parasitism to the host.
Essential amino acids are those that:
A. include minerals such as calcium and iron.
B. cannot be synthesized biochemically and must be taken in through the diet.
C. can only be found in plants.
D. provide essential vitamins
Evolution of a species could occur as a result of changes in the
Options for the question have not been provided. They are as follows:
(1) DNA in muscle cells
(2) base sequences in liver cells
(3) genes in an egg cell
(4) number of chromosomes in a fetal bone cell
Answer:
(3) genes in an egg cell
Explanation:
Evolution is the change in characteristics of a species which it develops over the time. These changes can be a result of natural selection, genetic drift, founder effect etc. They are passed from one generation to another hence the alleles for them get fixed in the population.
For evolution to occur, change should take place in germ cells. Germ cells are the one which fuse to form the organisms of next generation. If there is a change in their genes, it would also appear in next generation, unlike changes in genes of somatic cells. Since egg cell is a germ cell it is the correct answer.
Answer:
genes in an egg cell
Of the following, which is best supported to suggest where life is believed to have originated on Earth? Select one: a. RNA world hypothesis b. Primordial soup origin hypothesis c. Subsurface origin hypothesis d. Theory of natural selection
Answer: b. Primordial soup origin hypothesis
Explanation:
The primordial soup hypothesis is the basis of the origin of life on earth. Life originated in the ocean water as a result of the combination of chemicals from the atmosphere and energy from the sun to make up the amino acids. The amino acids are the building blocks of proteins. The protein was the basis of the development of life forms and their evolution on planet earth. The chemical evolution supposed to occur at least 3.8 billion years ago.
There are little birds that spend a great deal of time on the back of a rhinoceros and eat the blood sucking ticks out of the rhino's ears. Answer the following questions regarding these creatures' relationships. 1) The bird -rhino relationship is an example of: a) parasitism b) mutualism c) predator- pray d) commensalism. 2) The bird-tick relationship is an example of: a) parasitism b) mutualism c) predator- pray d) commensalism. 3) The tick-rhino relationship is an example of: a) parasitism b) mutualism c) predator- pray d) commensalism
Answer:
1. b
2. c
3. d
Explanation:
The bird-rhino relationship is an example of mutualism.
What do you mean by mutualism?Mutualism is a type of symbiotic relationship where all species involved benefit from their interactions. While mutualism is highly complex, it can be roughly broken down into two types of relationship.
Mutualism describes the ecological interaction between two or more species where each species has a net benefit. Mutualism is a common type of ecological interaction.
Mutualisms occur in every aquatic and terrestrial habitat; indeed, ecologists now believe that almost every species on Earth is involved directly or indirectly in one or more of these interactions.
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plsssss helppp I need it in your own words and not copy and pasted pls
Variation in a trait is a required condition for natural selection to act on a population for that trait. Assuming a population of organisms only started with only one form of a trait, what are two ways variation in the trait could be introduced into the population? Explain your answer.
Mutation and genetic recombination through sexual reproduction are two ways variation in a trait can be introduced into a population.
Mutation: Mutations are spontaneous changes in the DNA sequence that can lead to new alleles, creating genetic variation.
- These mutations can occur due to errors in DNA replication, exposure to mutagens like radiation or certain chemicals, or even through transposons, which are DNA sequences that can move around within the genome.
- Mutations can result in new traits or alter existing ones, contributing to variation within a population. For example, a mutation may lead to a change in fur color in mammals or the production of a new enzyme that confers a survival advantage.
Genetic Recombination through Sexual Reproduction: Sexual reproduction involves the combination of genetic material from two parent organisms, resulting in offspring with unique combinations of alleles.
- During meiosis, the process by which sex cells (gametes) are formed, homologous chromosomes exchange genetic material through crossing over. This process results in genetic recombination, where alleles from different parents are shuffled and passed on to offspring.
- Additionally, fertilization combines genetic material from two different individuals, further increasing genetic diversity in the population. This genetic recombination introduces variation in traits, allowing for natural selection to act upon them.
Arthropods invaded land about 100 million years before vertebrates. This fact most clearly implies that ________.
a. arthropods have had more time to coevolve with land plants than have vertebrates
b. arthropods evolved before vertebrates did extant terrestrial
c. arthropods are better adapted to terrestrial life than are extant terrestrial vertebrates
d. vertebrates evolved from arthropods
Answer:
Arthropods invaded land about 100 million years before vertebrates. This fact most clearly implies that a. arthropods have had more time to co-evolve with land plants than have vertebrates
Explanation:
Arthropods are invertebrates animals. Its evolutionary ancestry dates back to the Cambrian period and they have had more time to co-evolve with land plants than have vertebrates. The vertebrates share a common ancestor. Scientists believe that the last common ancestor of all arthropods is a modular organism with each module covered by its own sclerite.
In which of the following patterns of disease does the patient experience no signs or symptoms?
A) decline
B) prodromal
C) convalescence
D) incubation
E) incubation and convalescence
Answer:
The correct answer is option E) "incubation and convalescence".
Explanation:
The incubation period of an infectious disease is defined as the lapse between when a person is infected and the first symptoms are onset. While the convalescence stage is defined as the gradual recovery that a person experience once she or he overcomes the infectious disease. In both, the first and the last stage of the infectious disease (incubation and convalescence, respectively) the patient does not experience signs or symptoms of the disease.
describe the role of nuclear fusion in the life cycle of a star.
Nuclear fusion is essential in a star's life cycle, as it provides energy through the fusion of hydrogen into helium during the main-sequence phase and leads to the creation of heavier elements as the star ages and potentially explodes as a supernova.
Explanation:The Role of Nuclear Fusion in the Life Cycle of a StarNuclear fusion plays a critical role in the life cycle of a star, providing the energy necessary for a star to shine and influencing its evolution. During the main-sequence stage, which a star spends most of its life in, hydrogen nuclei (protons) fuse together to form helium in the core of the star. This process, known as the proton-proton cycle, occurs at extreme temperatures and pressures, as in our sun's core which is about 14 million kelvin. The nuclear fusion of hydrogen into helium releases a substantial amount of energy, which maintains the star's luminosity and supports it against gravitational collapse.
As a star exhausts the hydrogen in its core, it undergoes various changes - for example, it may expand to become a red giant. Eventually, depending on its mass, it will fuse heavier elements and may end its life in a supernova explosion, contributing newly created elements to the cosmos, including those heavier than iron.
Thus, nuclear fusion not only keeps stars shining but also produces new elements, contributing to the chemical diversity of the universe.
A fossil is discovered that has only 12.5% of the carbon-14 that it would have had originally (when the animal was alive). If the half-life of carbon-14 is 5700 years, approximately how old is the fossil?
Answer:
The fossil is 17,100 years old.
Explanation:
The decay equation:
[tex]\frac{dN}{dt}\propto -N[/tex]
[tex]\Rightarrow \frac{dN}{dt}= -\lambda N[/tex]
[tex]\Rightarrow \frac{dN}{N}= -\lambda dt[/tex]
Integrating both sides
[tex]\Rightarrow \int\frac{dN}{N}= \int-\lambda dt[/tex]
[tex]\Rightarrow ln |N|=-\lambda t+c[/tex]
When t=0, N=[tex]N_0[/tex] = initial amount
[tex]ln |N_0|=-\lambda .0+c[/tex]
[tex]\Rightarrow ln |N_0|=c[/tex]
[tex]\therefore ln |N|=-\lambda t+ln|N_0|[/tex]
[tex]\Rightarrow ln |N|-ln|N_0|=-\lambda t[/tex]
[tex]\Rightarrow ln |\frac {N}{N_0}|=-\lambda t[/tex]
[tex]\Rightarrow \frac {N}{N_0}=e^{-\lambda t}[/tex]
[tex]\Rightarrow N=N_0e^{-\lambda t}[/tex]
The decay equation is
[tex]N=N_0e^{-\lambda t}[/tex]
Given that,
The half life of carbon - 14 is 5700 years.
For half life, [tex]N=\frac{1}{2} N_0[/tex]
To find the value of [tex]\lambda[/tex], we need to put the value of N and t in the decay equation.
[tex]\frac12N_0=N_0e^{-\lambda \times 5700}[/tex]
[tex]\Rightarrow \frac12=e^{-\lambda \times 5700}[/tex] [ Divided [tex]N_0[/tex] both sides]
Taking ln both sides
[tex]\Rightarrow ln| \frac12|=ln|e^{-\lambda \times 5700}|[/tex]
[tex]\Rightarrow ln| \frac12|={-\lambda \times 5700}[/tex]
[tex]\Rightarrow \lambda= \frac{ln| \frac12|}{-5700}[/tex]
[tex]\Rightarrow \lambda= \frac{ln|1|-ln|2|}{-5700}[/tex] [ [tex]ln|\frac mn|= ln |m|-ln |n|[/tex]]
[tex]\Rightarrow \lambda= \frac{ln|2|}{5700}[/tex] [ln 1= 0]
The fossil has only 12.5% of the carbon carbon-14 that it would have had originally.
So, [tex]N=\frac{12.5}{100} N_0[/tex]
Then,
[tex]\frac{12.5}{100} N_0=N_0e^{-\frac{ln|2|}{5700}t[/tex]
[tex]\Rightarrow \frac{12.5}{100} =e^{-\frac{ln|2|}{5700}t[/tex]
Taking ln both sides
[tex]\Rightarrow ln|\frac{12.5}{100} |=ln|e^{-\frac{ln|2|}{5700}t}|[/tex]
[tex]\Rightarrow ln|\frac{12.5}{100} |={-\frac{ln|2|}{5700}t}[/tex]
[tex]\Rightarrow t=\frac{ ln|\frac{12.5}{100}|} {-\frac{ln|2|}{5700}}[/tex]
[tex]\Rightarrow t=\frac{ ln|\frac{12.5}{100}|\times 5700} {-{ln|2|}}[/tex]
[tex]\Rightarrow t=17,100[/tex]
The fossil is 17,100 years old.
In what ways do you think marine geography benefits marine science?
Marine biologists study biological oceanography and the associated fields of chemical, physical, and geological oceanography to understand marine organisms.
Why is it important to study marine science?Marine science recreates key role in the ongoing search to understand our world and to control its resources.
The interdisciplinary nature of the Marine Science curriculum will organise students to analyze deeply such co occuring issues as environmental alter, human clashes on the ocean, and biodiversity.
Thus, Marine biology is the study of marine organisms, their behaviors and relation with the environment.
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A mother with type A blood and genotype IAi and a father with blood type B and genotype IBi have children who grow up and become regular blood donors. Of the possible children, which genotype would have the least valuable blood to donate?
IAIBAAAO
As a seed plant germinates, the new plant is called a(n) after the leaves first open.
Answer: seedling
Explanation: took test got 100%
can you please give brainliest or heart
As a seed plant germinates, the new plant is called a(n) seedling, after the leaves first open.
After the leaves first open, the new plant is termed a "seedling." This phase marks the early stage of growth after germination, where the plant begins to establish itself above the soil surface. Seedlings typically possess embryonic leaves, or cotyledons, which initially provide nutrients to support early growth until true leaves develop. These true leaves are the first set of foliage that emerge after the cotyledons and represent the plant's ability to undergo photosynthesis independently.
During the seedling stage, the plant undergoes rapid growth as it acclimates to its environment, develops its root system, and strengthens its stems and leaves. Seedlings are vulnerable to environmental factors such as temperature fluctuations, water availability, and competition from neighboring plants or pests.
Proper care during this phase, including adequate watering, sunlight exposure, and protection from adverse conditions, is essential for promoting healthy seedling growth and ensuring successful establishment into mature plants.
What is the correct sequence that describes the excitation and contraction of a skeletal muscle fiber?
A bird flew and landed on its swing. When the bird "hit" the swing, the swing began to move back and forth. What happened when the bird landed on the swing?
A. Energy was transferred from the air to the swing.
B. The swing and the bird gained energy.
C. The swing's energy and the bird's energy each stayed the same.
D. Some of the bird's energy was transferred to the swing.
Answer:
the correct answer is D
Explanation:
Answer:
answer is d
Explanation:
i took the test and got it
In certain prairie community, a dominant prairie grass species has recently been infected with a virus that disrupts one of the electron transport proteins in the chloroplasts of infected cells. DESCRIBE and EXPLAIN the most likely effects on individual infected plants. *
Explanation:
The electron transport chain represents the directional flow of electron through electron carriers in the chloroplast and mitochondria in the cell.
The electron transport chain in the chloroplast is involved in the production of the ATP and NADPH. These molecules are synthesized during the light-dependent phase of the photosynthesis process.
If the prairie grass is affected with a virus that interferes with the electron transport chain occurring in chloroplast then the ATP and NADPH will nor be synthesized as a result of which the Calvin cycle will not proceed which require these intermediate to produce glucose. The plant will die ultimately die because of this virus.
Which of these energy transformations is taking place in the kelp as it carries
out photosynthesis?
O
A. Solar energy → Chemical energy
O
B. Potential energy → Kinetic energy
O
C. Chemical energy
Solar energy
O
D. Potential energy → Nuclear energy
SUBMIT
The specific type of energy transformation that takes place during photosynthesis is Solar energy to Chemical energy (Option A).
What is photosynthesis?Photosynthesis is a series of chemical reactions by which plant cells and algae use the energy from the sun (sunlight) to produce simple carbohydrates (i.e., sugars).
Photosynthesis needs oxygen, water (H2O) and sunlight or solar radiation to produce glucose (sugar) and carbon dioxide (CO2).
In conclusion, the specific type of energy transformation that takes place during photosynthesis is Solar energy to Chemical energy (Option A).
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A series of reciprocal evolutionary adaptations in two species is called _____.
Answer:
coevolution.
Explanation:
A series of reciprocal evolutionary adaptations in two species is called _____. coevolution.
According to the article, how does human activity affect the availability of food for deer populations? What result does this have on the deer populations? It's a timed test so please hurry if you can!!
Answer:
its b i just did this so she can get brainliest
however you speel it lol
Explanation:
What are National Marine Sanctuaries? Briefly describe them and why we need more than just these sanctuaries.
Answer:
a federally designated area within United States waters that protects areas of the marine environment with special conservation
Explanation:
to protect its natural and cultural features while allowing people to use and enjoy the ocean a sustainable way. Sanctuary waters provide a secure habitat for species close to extinction and protect historically significant shipwrecks and artifacts
Answer:
The sanctuaries help protect the marine ecosystem and wildlife in that area. It protects areas from fishing and pollution. They help keep the marine ecosystems alive and thriving.
*WARNING* Do not copy word for word or you'll be plagarising!
Explanation:
Santuaries are areas that governments help protect from hurtful human activity.
In multicellular organisms A. somatic mutations are passed on to offspring produced by sexual reproduction. B. somatic mutations may be passed to daughter cells by mitosis. C. all mutations produce phenotypic changes. D. meiosis is not required for the transmission of germ line mutations to the next generation. E. all mutations are point mutations.
Answer:
B. somatic mutations may be passed to daughter cells by mitosis.
Explanation:
In multicellular organisms, somatic mutations may be passed to daughter cells by mitosis.
Mitosis has to do with the division of somatic cells as opposed to germ or reproductive cells. Hence, daughter cells from mitosis are exact copies of their parents. If a mutation occur in the somatic cell of a parent, such could be passed to the daughter cell through mitosis.
Somatic mutations cannot be passed via sexual reproduction. Sexual reproduction can only be used to passed germline mutations.
Not all mutations produced phenotypic changes. Some mutations are silent and have no phenotypic implications.
Not all mutations are point mutations.
The correct option is B.