Answer:
Rudolf virchow in 1855
Explanation:
He said omnis cellula - e - cellula.
Mean cells formed from pre existing cells.
Final answer:
Rudolf Virchow developed the hypothesis that cells only come from other cells, which later became a central part of cell theory. Although, it should be noted that Robert Remak had published similar findings earlier, leading to a controversy. This principle complements earlier work by Schwann and Schleiden about the cell as the basic unit for all life.
Explanation:
The hypothesis that cells only come from other cells was developed by the German doctor Rudolf Virchow in 1858. This concept, a central part of cell theory, was summarized by Virchow using the Latin phrase omnis cellula a cellula, which means "all cells arise from cells." However, it's important to note that Robert Remak, a Polish scientist, and Virchow's former colleague, had published similar findings in 1852 and Virchow's lack of acknowledgment led to controversy over the credit for this aspect of cell theory.
Before Virchow, Theodor Schwann and Matthias Jakob Schleiden had suggested, in the early 1800s, that cells were the basic building blocks of all living things, setting the stage for the later development of cell theory. Virchow's observation of cell division under the microscope led to the realization that living cells can only arise from pre-existing cells, effectively refuting the idea of spontaneous generation and contributing to what we now understand as the modern cell theory.
The Cell Theory is now a fundamental principle of biology asserting that all organisms are made up of cells, all life functions take place within cells, and every cell originates from another pre-existing cell through the process of cellular division.
Which of the following best describes egg production in the female reproductive system?
A diploid cell undergoes meiosis to produce one egg and 3 polar bodies with 23 chromosomes each.
A diploid cell undergoes meiosis to produce four egg cells with 23 chromosomes each.
A haploid cell undergoes meiosis to produce four egg cells with 23 chromosomes each.
A haploid cell undergoes meiosis to produce one egg and 3 polar bodies with 23 chromosomes each.
Answer:
A diploid cell undergoes meiosis to produce one egg and 3 polar bodies with 23 chromosomes each.
Explanation:
During egg formation in the ovary, Primary oocyte (diploid) having 46 chromosomes undergoes meiosis I to form one secondary oocyte and one first polar body. Both the secondary oocyte and one polar body are haploid having 23 chromosomes. Both daughter cells then undergo meiosis II, the first polar body divides to give two polar bodies and the secondary oocyte divides by meiosis II to form one ovum. Therefore, during egg formation in the reproductive system, a diploid cell (a primary oocyte) undergoes meiosis to produce one egg and 3 polar bodies with 23 chromosomes each.
All living organisms on earth grow, maintain homeostasis, and undergo cell division. Prior to cell division, cells must undergo DNA synthesis to ensure an accurate copy of DNA is distributed to each daughter cells. DNA replication is similar in nearly all cells across all three domains, indicating that life on earth likely shares a common ancestry. Which part of the model of the cell cycle provides this shared feature of life on earth, DNA synthesis?
D) S is the answer to the question
Answer:
The correct answer will be- S phase or synthesis phase.
Explanation:
The cell cycle is the ordered series of events which explains the distribution of the nucleus and the cytoplasm of the cell.
The cell cycle takes place in two phases: M-phase and interphase. The interphase is divided into three stages: G₁, S and G₂ phase.
The phase involved with the replication of the DNA is known as the S phase or synthesis phase. It is the S phase which is highly conserved among all the domains of the classification system and thus, S phase is the correct answer.
What two terms are used for an organism’s binomial name
Answer:
the first word is genus and the second is species
Which of the following is the muscle protein that binds and stores oxygen to maintain aerobic conditions in actively contracting muscle?
a. calmodulin
b. myoglobin
c. hemoglobin
d. troponin
Your answer should be B. “Myoglobin”
mark me brainliest please!
Which structure of a flowering plant contains female reproductive cells, or eggs?
Answer: ovules
Explanation: Each carpel includes an ovary (where the ovules are produced; ovules are the female reproductive cells, the eggs), a style (a tube on top of the ovary), and a stigma (which receives the pollen during fertilization). The Male Reproductive Organs: Stamens are the male reproductive parts of flowers.
Final answer:
The ovary is the structure within a flowering plant that contains female reproductive cells, or eggs, and is part of the gynoecium, including the stigma and style.
Explanation:
The structure of a flowering plant that contains female reproductive cells, or eggs, is the ovary. The ovary is part of the gynoecium, which comprises the stigma, style, and ovary. The eggs, housed within the ovary, are technically referred to as ovules until they are fertilized, at which point they can develop into seeds after successful pollination and fertilization processes. Flowers facilitate the reproduction of plants by ensuring the transfer of pollen from the male structure to the female structure, allowing the pollen tube to grow through the style to reach the ovary and thus fertilize the ovule.
How many complete molecules of dna do you begin with in dna replication?
Answer:
Well you began with 2 DNA replication
Explanation:
The tough superficial layer of the epidermis is known as the stratum
A) corneum.
B) lucidum.
C) basale.
D) granulosum.
E) spinosum.
Answer:
Stratum corneum
Explanation:
Epidermis is known to be the outmost layer of the skin and it is made up of stratified squamous epithelium and keratinized. Thus, stratum corneum is known to be the layer of the epidermis that is most superficial and that can be seen with our eyes. Furthermore, stratum corneum functions by preventing the dehydration of underlying tissues and microbes penetration
Which of the following conditions occurs when blood flow to the brain is interrupted and is a risk of high blood pressure? A. Heart attack B. Stroke C. Heart disease D. Atherosclerosis
Answer:
B. Stroke
Explanation:
Atherosclerosis refers to the formation of cholesterol-rich plaques in the inner lining of arteries. Atherosclerosis in cerebral arteries which function to provide oxygenated blood to brain cells leads to abrupt destruction of brain cells. Death of brain cells occurs due to oxygen deprivation. It is called a stroke or brain attack or cerebrovascular attack. Stroke poses a risk of developing higher blood pressure.
From where is it believed that most comets originate?
A) Orion’s Belt
B) Oort belt
C) Kuiper belt
D) asteroid belt
* I don’t know if I’m right I believe it is c someone correct me if I’m wrong
Final answer:
Most comets are believed to originate from the Oort cloud, which is the source of long-period comets, and the Kuiper belt, associated with short-period comets or Jupiter-family comets.
Explanation:
It is believed that most comets originate from two primary regions in our solar system: the Oort cloud and the Kuiper belt. The Oort cloud is an extensive shell of icy objects that lies far beyond Pluto, enveloping the solar system out to about 50,000 astronomical units (AU) from the Sun. This distant reservoir contains trillions of cometary nuclei and is the source of long-period comets, which can have orbits lasting hundreds or even thousands of years.
On the other hand, the Kuiper belt is a disk-shaped region beyond Neptune, extending to approximately 50 AU. It is made up of ice-and-rock planetesimals, which are remnants of the building blocks of the planets. This area is the origin of short-period comets, typically called Jupiter-family comets, which have shorter orbits lasting less than 200 years due to gravitational interactions with the giant planets, especially Jupiter.
While the Oort cloud is believed to house the majority of comets in the solar system, the Kuiper belt is responsible for a significant number of observable comets, including some that have been the target of spacecraft missions. Therefore, in response to the original question, it's important to recognize that both B) Oort cloud and C) Kuiper belt are sources of comets, but the Oort cloud is considered the primary reservoir for most comets.
Chemicals released into the space between nerve cells that bind to receptors are called
A. neurotransmitters.
B. action potentials.
C. platelets.
D. neurochemicals.
Answer:
A
Explanation:
Neurotransmitters are your body's chemical messengers. They carry messages from one nerve cell across a space to the next nerve, muscle or gland cell. Therefore, option (A) is correct.
What are neurotransmitter ?Without chemical messengers, also known as neurotransmitters, your body simply cannot work properly. They are in charge of carrying chemical "messages" from one neuron (nerve cell) to the subsequent target cell in the chain of cells. It's possible that the next cell to be targeted is a gland, a muscle cell, or even another nerve cell.
Neurotransmitters are molecules that go between cells and attach themselves to particular receptors located on the cells they are trying to communicate with. Every neurotransmitter has its own specific receptor that it binds to. Dopamine molecules, for instance, bind themselves to dopamine receptors in the brain. When they attach to one another, it sets off a chain reaction in the cells that they are targeting.
Therefore, chemicals released into the space between nerve cells that bind to receptors are called neurotransmitters.
Learn more about neurotransmitter, here:
https://brainly.com/question/9725469
#SPJ2
Which statement best describes the difference between the sympathetic and parasympathetic nervous systems? A. The sympathetic system prepares the body for stress and activity and the parasympathetic system prepares the body for rest. B. The sympathetic system sends signals within the brain and the parasympathetic system sends signals between the brain and the body. C. The sympathetic system contains the brain and spinal cord and the parasympathetic system contains the peripheral nerves. D. The sympathetic system controls voluntary body movements and the parasympathetic system controls involuntary functions.
Answer:
B) The sympathetic system prepares the body for stress and activity and the parasympathetic system prepares the body for rest.
Hope it helps.
Answer:
A. The sympathetic system prepares the body for stress and activity and the parasympathetic system prepares the body for rest.
Explanation:
The sympathetic and parasympathetic divisions are part of the autonomic nervous system and work antagonistically to each other.
The sympathetic nervous system is the one that prepares the body for "fight or flight" under emergency or stress conditions. On the other hand, the parasympathetic nervous system is related to the resting phase of the body.
The general effect of the sympathetic nervous system is to mobilize the energy while the parasympathetic nervous system serves to restore the energy level of the body.
In cows, long hair is dominant to short hair. in a cow that is heterozygous for long hair, what percentage of the cells undergoing meiosis will carry the dominant allele?
In a heterozygous individual, the cells which undergo meiosis will carry the dominant allele (long hair) in 50% of the resulting gametes. This is because meiosis results in gametes that each contain one copy of either the dominant or the recessive allele.
Explanation:In cows, long hair is dominant to short hair, meaning that it masks the presence of the short hair allele when they are present together in a heterozygous individual. If a cow is heterozygous for long hair, this means it has one dominant allele (long hair) and one recessive allele (short hair). In meiosis, the cells split to form gametes (sex cells), and each gamete will carry one allele from the pair. This means that, in a cow that is heterozygous for long hair, 50% of the cells will carry the dominant allele (long hair), and 50% will carry the recessive allele (short hair).
Using the concept of a test cross, as developed by Mendel, this can be determined by crossing the heterozygous individual with a homozygous recessive one. If the dominant-expressing organism is a heterozygote, the F₁ offspring will exhibit a 1:1 ratio of heterozygotes and recessive homozygotes, validating Mendel's postulate that pairs of unit factors segregate equally.
Learn more about genetics here:https://brainly.com/question/30459739
#SPJ12
Final answer:
In a heterozygous cow with one dominant allele for long hair, 50% of the cells undergoing meiosis will carry the dominant allele.
Explanation:
In a cow that is heterozygous for long hair, where long hair is the dominant trait, every cell undergoing meiosis will have one dominant allele and one recessive allele for hair length. During meiosis, chromosomes and their alleles are divided into gametes (egg or sperm cells), each receiving one from each pair. Therefore, 50% of the gametes will carry the dominant allele for long hair because the heterozygous parent has one dominant allele and one recessive allele. This can be represented with the letters L for the dominant long hair allele and l for the recessive short hair allele. Thus, the genotype of the heterozygous cow is Ll, leading to 50% of its gametes carrying the L allele after meiosis.
fill in the blank below with the word the best completes the sentence
___ determine how cells are identified
Answer:
science
Explanation:
this question is very vague. I'm so sorry if this is what the school was asking on a question. but cells are identified by humans, through science.
Answer:
the answer is genes
Explanation:
just did it on my assignment
What type of biological molecule is dna helicase?
Answer:
emzymes which is one of the biological catalysts
DNA helicase is an enzyme that separates the two DNA strands of a double helix during DNA replication. It untwists and separates these strands, resolving the supercoiling in the DNA and making it accessible for further replication. If helicase is mutated, this crucial separation wouldn't occur.
Explanation:DNA helicase is a type of biological molecule that is classified as an enzyme. Its primary function is to separate the two DNA strands of a double helix during the process of DNA replication. As the replication process initiates, special enzymes like helicase untwist and separate these two strands.
This process is often compared to unzipping a zipper. The action of helicase enzyme resolves the over-winding or supercoiling in the DNA ahead of the replication fork, a phenomenon caused by the opening of the double helix. This makes the single-stranded DNA template accessible to the DNA polymerase for the formation of a daughter strand. If helicase were to be mutated, the DNA strands wouldn't be separated at the beginning of replication.
Learn more about DNA helicase here:https://brainly.com/question/30842103
#SPJ6
Water molecules readily form hydrogen bonds with other polar molecules, and when they encounter nonpolar molecules they must form hydrogen-bonding networks with neighboring water molecules. Which of the following molecules will cause a "cage" of water to form?
Select one:
a. 2-methylpropane
b. acetone
c. methanol
d. urea
Answer:
a. 2-methylpropane
Hope this helps :)
Final answer:
A. 2-methylpropane will cause a cage of water to form around it because it is nonpolar, leading water molecules to maximize hydrogen bonding among themselves.
Explanation:
The molecule that will cause a "cage" of water to form due to its nonpolar nature is 2-methylpropane. Water is a polar solvent with molecules that can form up to four hydrogen bonds with each other or with other polar substances. Options like acetone, methanol, and urea, with their polar functional groups, are capable of interacting with water through hydrogen bonding.
But 2-methylpropane lacks this capability because it is nonpolar. As a result, water molecules around 2-methylpropane form a structured network, or clathrate cage, as they cannot bond directly with the molecule and instead maximize hydrogen bonding among themselves.
When anton asks vincent , “how are you doing this “how does vincent answer
Answer:
"I never saved anything for the swim back."
Answer:
hihi
Explanation:
Based on the soil texture diagram, what type of soil is 40 percent sand, 15 percent clay, and 45 percent silt? A. Loam B. Sandy loam C. Sandy clay loam D. Silt loam
The answer is A.) Loam.
I'm just asking/answering my own question to help people out!!
Answer:
Okay then, so the answer to this question is A) loam
Comments:
Thanks!
Sand, silt, and clay combine to make loam. Loam soil should have equal amounts of all three soil types.. Therefore option (A) is correct.
What is loam soil?Loam, A friable (crumbly) soil that is rich in nutrients and contains roughly equal percentages of sand and silt, with somewhat less clay. It is possible to use the term in a less specific sense to refer to dirt or soil in general at times. Leaching, also known as percolation, transfers minerals and clay from the topsoil above into the subsurface, where they are incorporated into the loam.
Clay, silt, and silty clay loam are examples. Different soil stages vary in stoniness and erosion, which don't effect native vegetation but can affect crop production.
Most garden plants prefer loamy soil because it absorbs moisture and drains well so roots can get enough air.
Therefore, option (A) is correct.
Learn more about Types of soil, here:
https://brainly.com/question/26139061
#SPJ2
A gene is a segment of DNA that codes for a particular protein. One DNA molecule typically contains thousands of genes. So, in order to fit into the nucleus of a cell, DNA molecules must be wound around proteins into structures known as
A gene is a DNA segment coding for proteins, wound around proteins into chromosomes to fit in the cell nucleus. Genes can vary in size and may lead to one or more proteins. The process involves transcription to mRNA and translation into amino acids.
A gene is a segment of DNA that contains the information to encode a specific protein or RNA molecule. To organize the extensive length of DNA within the compact nucleus of a cell, DNA strands are wound around proteins into structures called chromosomes. This compaction is essential because genes are composed of hundreds to thousands of base pairs, necessary for coding the proteins made from hundreds or thousands of amino acids.
Genes are not always a one-to-one blueprint for proteins; some proteins may need multiple genes, and some genes can result in more than one protein, depending on how the gene expression is regulated and influenced by the environment.
Lastly, the process by which the sequence of nucleotides in DNA is used to make a molecule of messenger RNA (mRNA), and then translated into the amino acid sequence of a protein, reflects the central tenets of molecular biology and the flow of genetic information.
How many chromosomes are found in a liver cell of a robertsonian translocation carrier?
Answer:
Image: nicerweb.com
In humans, when a Robesonian translocation joins the long arm of chromosome 21 with the long arm of chromosomes 14 or 15, the heterozygous carrier is phenotypically normal because there are two copies of all major chromosome arms and hence two copies of all essential genes
Explanation:
An area of land or water set aside for the protection of an ecosystem is a _____.
This is called a preserve
Hope this helped!
~Just a girl in love with Shawn Mendes
Besides distributing food, what is another role of the un's food for girls' education programme?
The answer is C: encouraging women’s education
Answer:
Encouraging women’s education
Explanation:
The un's food for girls program is an initiative that seeks to contribute to the education of girls in countries where girls do not have the opportunity to receive appropriate education.
In some countries, people believe that women should not study but rather help with household chores. they believe that only men can receive education since it is they who must work and provide for the family. For this reason, the rate of illiteracy among women is very high.
Thus, the un's food for girls proposes to encourage girls' education by donating food for families to send their girls to school so that they can have access to education.
New species can form through allopatric or sympatric speciation. Which of the following mechanisms will act more strongly on populations that are initially separated in allopatry than on those initially separated in sympatry?reinforcementgenetic driftgene flowdisruptive selection
Answer:
genetic drift
Explanation:
Allopatric speciation is a form of speciation (creation of new species) that occurs as a result of geographic isolation. This means that a part of population becomes physically separated from the initial main population. There is no gene flow between these two populations and as a result the two populations reach a high level of genetic divergence. They can no longer interbreed which means they become two different species (speciation) .
New populations evolve as result of mutation, genetic drift and natural selection.
Sympatric speciation is a form of speciation without geographic isolation, usually due to the reproductive isolation or changes in the chromosomes of the organism.
Whereas some modern whales possess a small and useless __________ pelvis
Answer:
vestigial is the answer
A metamorphic rock interacts with the layers of Earth and melts because of extreme heat and pressure. Which of these is most likely formed when the molten rock cools?
Magma
Sediments
Sedimentary Rocks
Igneous Rock
Answer:
The correct answer is igneous rocks.
Explanation:
Igneous rocks or magmatic rock is one of the 3 major rock types. Igneous rock is made by the cooling and solidification of lava or magma. Igneous rocks is of two type on the basis of their formation, if the magma crystallizes below the surface of earth and slow cooling form the big crystals of rocks is called intrusive igneous rock whereas extrusive igneous rocks are the rocks which are crystallized from the volcanic magma poured out on the surface of the earth by slow cooling. Extrusive igneous rocks are also known as volcanic rocks.
Thus, the correct answer is igneous rocks.
Which cell organelle is the site of protein synthesis?
A.)endoplasmic reticulum
B.)ribosome
C.)nucleus
D.)mitochondrion
Im gonna say C. Nucleus
The site of protein synthesis in a cell is the ribosome, which translates the cell's DNA instructions to produce proteins. Therefore, the correct answer is 'B) Ribosome'.
Explanation:The cell organelle that is the site of protein synthesis is the ribosome. Ribosomes, which can be found either floating freely within the cell or attached to the endoplasmic reticulum, are responsible for the production of proteins. They do this by translating the instructions encoded in the cell's DNA. This process involves linking together amino acids in the specific sequence dictated by the DNA's instructions to form a protein molecule. So, the correct answer to your question is 'B) ribosome'.
Learn more about Protein Synthesis here:https://brainly.com/question/32660015
#SPJ6
Which characteristic could be used to identify a biome?
A. The complexity of the food web in the region.
B. Types of endangered species that live there.
C. Amount of precipitation the region receives.
D. The history of human impact on the region.
Answer:
C. Amount of precipitation the region receives.
Explanation:
The visual information used by honeybees includes what elements that are not apparent to humans?
ultraviolet (UV) light maybe?
Your ability to drive safely can be impaired by use of certain over-the-counter drugs true or false
Answer: it's True
Explanation:
Medication that are used to treat allergies or colds can cause drowsiness which can cause you to feel sleepy while driving.
Medication used for diets or supplements could also cause excitability and can make you hyperactive while driving.
What's a disadvantage of the point count method of population monitoring? It leads to the death of the sampled individuals. It only records trends in population at fixed locations in the ecosystem. It requires traversing through the ecosystem, which may be difficult in rugged terrain. It's only useful for monitoring organisms that are fixed in one place. It requires capturing the animal for a brief period of time.
Answer:
It only records trends in population at fixed locations in the ecosystem.
Explanation:
The point count method is a method used to monitor the populaton of birds in certain places that consists on having someone fixed at one spot and record all the birds that he can spot by sight and by ear, so if he sees or hears a certain bird he records it, to have a close idea of the species of birds that there are in a certain location, the problem would be that it only records trends at fixes locations in the ecosystem.
The disadvantage of the point count method of population monitoring is that It only records trends in population at fixed locations.
What is Point count method?This is a method which involves the counting of species in an ecosystem with the individual being fixed at a point and counts on sight.
This system of counting only records trends in population at fixed locations.
Read more about Point count method here https://brainly.com/question/7194772
#SPJ2
What is the relationship between the number of motor neurons recruited and the number of skeletal muscle fibers innervated?a) Motor neurons always innervate thousands of skeletal muscle fibers.b) A skeletal muscle fiber is innervated by multiple motor neurons.c) Typically, hundreds of skeletal muscle fibers are innervated by a single motor neuron.d) A motor neuron typically innervates only one skeletal muscle fiber.
Answer:
c) Typically, hundreds of skeletal muscle fibers are innervated by a single motor neuron.
Explanation:
A motor neuron is a neuron that controls the effector organs such as muscles and glands. One single motor neuron usually inervates many muscle fibres. An individual motor neuron together with all of the muscle fibers that it innervates comprises a structure called motor unit. The number of fibers innervated by a motor unit is known as innervation ratio.
The number of motor neurons recruited and the number of skeletal muscle fibers innervated is defined by the motor unit. Typically, hundreds of skeletal muscle fibers are innervated by a single motor neuron. The specific innervation ratio depends on the muscle's function.
Explanation:The relationship between the number of motor neurons recruited and the number of skeletal muscle fibers innervated is defined by the motor unit, which is a single motor neuron and all of the muscle fibers it innervates. Typically, a single motor neuron innervates hundreds of skeletal muscle fibers, but this can vary widely depending on the function of the muscle. Muscles used for precise movements (like the fingers or eyes) have fewer muscle fibers per motor neuron, while larger, stronger muscles (like the thighs or back) have more muscle fibers per motor neuron. This is known as the innervation ratio.
Learn more about Motor Neurons and Muscle Fibers here:https://brainly.com/question/32266597
#SPJ6