Answer:
a) the pyrimidine ring is assembled before being bonded to the ribose phosphate, whereas the purine ring is bonded to the ribose phosphate as it is formed
Explanation:
There are two ways for the synthesis of purines and pyrimidines:
de novo synthesis-from basic simple units"recycling" synthesis-reuse of metabolitesPurines are synthesized directly on ribose sugar, in segments.
Pyrimidines are attached to the ribose after the synthesis of the base.
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.
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.
Do earthworms have a front and a back end? Explain your answer.
Yes, earthworms have a front and a back end. The front end is called the anterior end and the back end is called the posterior end. The anterior end has a mouth for consuming food and sensory organs, while the posterior end has an anus for excreting waste.
Explanation:Yes, earthworms have a front and a back end. The front end of an earthworm is called the anterior end, while the back end is called the posterior end.
At the anterior end, earthworms have a mouth that they use to consume food. They also have sensory organs called prostomium and peristomium that help them detect their environment.
At the posterior end, earthworms have a small opening called the anus through which they excrete waste.
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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.
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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.
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
Which two substances bind using a lock-and-key mechanism?
Enzymes and Substrates! Hope this helps, and have a nice day.
Cells in the pancreas produce insulin (a protein) for export. which structure is required for this function?
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.
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When Mendel crossed yellow-seeded and green-seeded pea plants, what happened?
Answer:
Offspring in F1 generation had yellow-seeded pea plants.
Explanation:
When Mendel used yellow-seeded and green-seeded pea plants as parents plants he noticed that all of the offspring of the first generation (F1) were yellow-seeded plants. In the next following generation (F2), phenotype ratio was 3:1 (yellow:green).
After this observation Mendel conclude that yellow-seeded plants are dominant over green-seeded plants. Since he used purebred plants, genotypes were:
P: AA x aa
F1: Aa Aa Aa Aa
F2: AA Aa Aa aa
AA and Aa are genotypes for the yellow seeds, while aa is genotype for green seeds.
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.
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:
In plant cells what forms midway between the divided nuclei during cytokinesis
Answer:
Cell plate
Explanation:
Cell plate is a plate that forms during the cytokinesis of the plants, and helps in separation of chromosomes in two new cells and in new cell wall formation. Vesicles that contain components for the new cell wall and cell membrane) are transported from the Golgi apparatus to the to the plane of cell division. Vesicles fuse within the plate. Direction of the cell plate growth is from the center towards the plasma membrane. This growth depends on phragmoplast, structure that acts as a scaffold. When cytokinesis is complete, cell plate becomes the new cell wall.
In plant cells, a structure known as the cell plate forms midway between the divided nuclei during cytokinesis. This process involves Golgi vesicles coming together at the former metaphase plate, forming a phragmoplast. The cell plate, formed from the fusion of these vesicles, grows outwards to the cell walls, eventually becoming the new cell wall.
Explanation:During cytokinesis in plant cells, following the division of the nucleus, a structure known as the cell plate forms midway between the divided nuclei. This important process is facilitated through the help of Golgi vesicles that coalesce at the former metaphase plate, creating a structure referred to as a phragmoplast.
The cell plate, created by the fusion of these vesicles, grows from the center towards the cell walls. The membranes of the Golgi vesicles effectively fuse to form a new plasma membrane that divides the parent cell into two daughter cells. The cell plate further develops into the newly formed cell wall that separates the two newly created cells post cell division.
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What characteristics can you observe in the gills that make them an efficient respiratory organ?
Answer:
Lots of folding = lots of surface area for diffusion.
Lots of vascularization.
Countercurrent exchange system.
Located off of the throat to help water get rammed down the throat in a single direction, across the gills
Gills are highly efficient at facilitating gas exchange due to their large surface area, highly branched and folded structure, and proximity to blood capillaries allowing for rapid diffusion of dissolved oxygen from water into the bloodstream.
The gills of aquatic organisms such as fish are highly efficient respiratory organs. These gills are thin tissue filaments that are highly branched and folded, which increases the surface area for gas exchange. This extensive surface area is critical for allowing sufficient oxygen intake. It is said that the surface area of some fish gills can be as expansive as a handball court, indicating just how large the area for gas exchange can be.
Gills function by having water flow over them, where the dissolved oxygen is rapidly diffused from the water into the bloodstream of the fish. This occurs because of the close proximity of the capillaries to the gill surfaces, with a minimal diffusion distance that facilitates quick and efficient oxygen transfer. The oxygen that enters the bloodstream can be efficiently distributed throughout the body. Moreover, gills are constantly in contact with water, which allows them to take up oxygen without the organism needing to breathe air.
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.
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.
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.
30) Which of these is NOT a way that large molecules, like glucose, can enter a cell? A) diffusion through the cell membrane. B) facilitated diffusion through protein channels in the cell membrane. C) endocytosis, when the cell engulfs the particles with pseudopods. D) active transport, when the cell pumps large molecules in through the membrane.
Answer:
the answer is B.
Explanation:
To have an impact on the evolution of a species what criteria does a behavior have to meet
A behavior must affect an organisms fitness and have a genetic basis.
Answer:
For evolution to happen the main points are as follows:
-High rate of reproduction
- Struggle for existence
- Variation
- Survival of the fittest
- Natural selection
Explanation:
The success in survival and reproduction depends upon the characteristic traits of an organism, for example only those rabbits will survive which are fastest. There is struggle for existence and in this there will be survival of the fittest. The phrase survival of fittest was first used by Herbert Spencer. The same context was asserted by Darwin as Natural selection.
Bile salts aid in the digestion of fats by ________ large fat droplets.
binding
emulsifying
anabolizing
dehydrating
combining
Answer:
emulsifying
Explanation:
Bile salts secreted from the bill has an important role in emulsification of lipids. They have the ability to aggregate around lipids thanks to their amphipatic nature. Amphipatic nature means that they have hydrophobic side which binds directly to lipids and hydrophilic side which are faced outwards. Lipids enveloped with bile salts are called micelles.
Formation of micelles increases the surface area of fat, which is appropriate for the the action of the enzyme pancreatic lipase (perform digestion of triglycerides).
Bile salts assist in fat digestion by emulsifying, or breaking down, large fat droplets into smaller ones, increasing the surface area for enzymes to work on. This makes the fats more easily digestible and absorbable by the body.
Explanation:Bile salts aid in the digestion of fats by emulsifying large fat droplets. Emulsification is the process of breaking down large fat droplets into smaller ones, enhancing the surface area for enzymes to act upon. Bile salts, produced by the liver and stored in the gallbladder, surround and break down the large fat droplets, making them more accessible to the digestive enzymes. After the action of bile, these smaller droplets of fats can be further digested by the enzyme lipase into fatty acids and glycerol. So, bile salts play a crucial role in the digestion and absorption process of fats in the body.
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What two terms are used for an organism’s binomial name
Answer:
the first word is genus and the second is species
Carbohydrates, more commonly known as sugars, are made up of carbon, oxygen, and hydrogen atoms. The smallest unit of a carbohydrate is a monosaccharide. Two monosaccharides make up a disaccharide, and many monosaccharides make up a polysaccharide. Disaccharides and polysaccharides can be hydrolyzed back into the individual monosaccharide units. Part A Select the statement that is incorrect. View Available Hint(s) Select the statement that is incorrect. Complex sugars are carbohydrates. All carbohydrates have the general formula Cn(H2O)n. Simple sugars are carbohydrates. Carbohydrates contain only carbon, oxygen, and hydrogen atoms.
Answer:
All carbohydrates have the general formula Cn(H2O)n
Explanation:
The basic unit of carbohydrates-monosaccharides have the formula C nH 2nO n while the basic general formula of carbohydrates is Cm(H2O)n .
Monosaccharides are basic units (components) of carbohydrates. Those are simple sugars such as glucose, fructose, galactose. Two monosaccharides can join together via glycosylic bond and make disaccharides. Some of the disaccharides are: sucrose (glucose + fructose), lactose (galactose + glucose), maltose (glucose + glucose).
Disaccharides can be broken down to monosaccharides by an enzyme called a disaccharidase.
Longer chains of monosaccharides form oligosaccharides (usually as glycolipids ) and polysaccharides (starch, glycogen,cellulose, chitin).
Carbohyrates are important biomolecules included in metabolism, energy storage, they are also structural components, have role in immune response, as coenzymes etc.
Carbohydrates are organic molecules made up of carbon, hydrogen, and oxygen atoms. They are classified into monosaccharides, disaccharides, and polysaccharides. Monosaccharides are the smallest carbohydrate unit, while disaccharides and polysaccharides are made up of multiple monosaccharides joined together.
Explanation:Carbohydrates, also known as sugars, are organic molecules composed of carbon, hydrogen, and oxygen atoms. They are classified into three types: monosaccharides, disaccharides, and polysaccharides. Monosaccharides are the smallest unit of carbohydrates and include glucose, fructose, and galactose. Disaccharides, such as sucrose and lactose, are formed by the linkage of two monosaccharide units. Polysaccharides, like starch and cellulose, are made up of many monosaccharides joined together in long chains.
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The visual information used by honeybees includes what elements that are not apparent to humans?
ultraviolet (UV) light maybe?
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.
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:
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.
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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.
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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:
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.
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
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”
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