Answer:
Colchicine
Explanation:
Colchicine is an alkaloid derived from the autumn crocus (Colchicum autumnale).
The effect of colchicine, which inhibits microtubule polymerization and thus assembly of the mitotic spindle, demonstrates the presence of another checkpoint in the cell cycle. When colchicine is added to cultured cells, the cells enter mitosis and arrest with condensed chromosomes. With increasing time, a large fraction of the cells in a culture become arrested, thus permitting determination of the size, shape, and number of mitotic chromosomes — that is, the karyotype — in multiple cells. A checkpoint control somehow senses when the mitotic spindle has not assembled properly and prevents activation of the APC polyubiquitination system that normally leads to degradation of the anaphase inhibitor, required for onset of anaphase, and later to the degradation of mitotic cyclins, required for the exit from mitosis. As a result, MPF activity remains high, chromosomes remain condensed, and the nuclear envelope does not re-form.
Ion channel gates close the pores of some ion channels in response to
Select one:
a. a change in electrical charge.
b. stretching of the cell membrane.
c. the binding of specific molecules to the channel.
d. All of the above
Answer:
All of the above
Explanation:
The ions present in our body can move through voltage gated ions channels present in the cell. The ions are unequally distributed in the interior and exterior of the cell.
The ion gated channel may get open or close depending upon the presence of the different ions. These ions movement changes the electric potential of the cell. The ions movement results in the propagation of the nerve impulse and may cause the cell membrane stretching. The binding of the molecules to the ion channels may open or close the movement of particular ions.
Thus, the correct answer is option (d).
Final answer:
Ion channel gates can close in response to changes in electrical charge, mechanical stretching of the cell membrane, or the binding of specific molecules, meaning 'All of the above' is the correct answer.
Explanation:
Ion channel gates are integral components of cellular membranes and respond to various stimuli to maintain the cell's homeostasis. The closing of the pores of ion channels can occur due to a change in electrical charge, resulting from a change in membrane potential; mechanical stretching of the cell membrane, which can be detected by mechanically gated channels; or the binding of specific molecules to the channel, such as ligand-gated ion channels responding to neurotransmitters, or the interaction with G-proteins that may indirectly lead to channel opening.
Therefore, when we consider the stimuli that can lead to the closing of ion channel gates, the correct answer to the question is d. All of the above. Ion channels allow rapid and selective ion transport across cellular membranes, contributing to crucial processes such as the transmission of nerve impulses and muscle contraction.
Non-disjunction involving the X-chromosome may occur during oogenesis and produce two kinds of eggs. If normal sperm fertilize these two types, which of the following pairs of genotypes are possible?
a. XX and XY
b. XXY and XO
c. XYY and XO
d. XYY and YO
Answer:
The correct answer will be option-B
Explanation:
Non-disjunction is the process of the failure of the separation of the homologous chromosomes during cell division which could be observed during the meiosis I, meiosis II or mitosis.
If Non-disjunction takes place during the oogenesis then the resultant cells will be formed with XX and O gametes.
When a normal male sperm with XY fertilizes the cells then they will form four combinations:
1. XX + X = XXX
2. XX + Y = XXY
3. O + X = XO
4. O + Y = YO
Thus, in the given question option-B is the correct answer.
Non-disjunction involving the X-chromosome during oogenesis can produce two types of eggs: XX and O. When these are fertilized by normal sperm, the viable genotypes that can result are XXY and XO. YO is not a viable genotype and will not develop.
Explanation:The term non-disjunction in biology refers to the failure of chromosome pairs to separate properly during cell division, which can result in aneuploidy. Aneuploidy is a condition in which a cell has an abnormal number of chromosomes. Specifically in the context of this question, non-disjunction involving the X-chromosome during oogenesis (egg production) can produce two types of eggs: one with two X chromosomes (XX) and one without an X chromosome (O). When normal sperm (either X or Y) fertilize these two types of eggs, four combinations are possible: XX, XY, XO, or YO.
The viable combinations, however, are XX and XO. This is because an embryo with the genotype YO (having only a Y chromosome and no X chromosome) is not viable and won't develop. Thus, the correct answer is option 'b. XXY and XO'.
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Marfan's syndrome is the result of inheriting a single allele. Individuals with Marfan's syndrome are tall and long-limbed, and have both cardiovascular and eye defects. The inheritance of Marfan's syndrome is an example of?
Answer:
Pleiotropy
Explanation:
Marfan syndrome is an example of pleiotropy, which can be defined as the phenomenon in which a pair of allele genes conditions the appearance of several traits in the same organism.
All of these traits occur through the action of only one pair of genes, so pleiotropy shows that the idea that each gene affects only one trait is not always valid.
In other words, a pleiotropic gene can have an effect on several phenotypes at the same time, due to the fact that the mutated gene is used by a group of cells (or targets) that have the same signaling function.
Carbonydrate loading a. provides a competitive edge for award-winning sprinters, bodybuilders, and weight lifters b. involves manipulating dietary patterns and physical activities prior to an endurance event c. often results in short-term weight loss and positive energy balance d. is generally recommended for long-term weight control for athletes
Answer: Option B.
Carbohydrate loading involves manipulating dietary patterns and physical activities prior to an endurance event.
Explanation:
Carbohydrate loading is a method used by endurance athletes to increase their glycogen (energy level) storage in the muscles and livers by changing their diets and physical exercises. This is done a week before an endurance activity and it is my increasing the intake of Carbohydrates by 8 to 12 kilogram by weight of the body. This give you more energy to compete for physical activity with less fatigue for a long period of time as we know that physical activity requires energy.
It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in which of the following? Group of answer choices sequence of bases side groups of nitrogenous bases complementary pairing of bases phosphate—sugar backbones different five-carbon sugars
Final answer:
The DNA molecule carries a vast amount of hereditary information in the sequence of bases, which enables precise replication and transmission of genetic information, essential for protein synthesis and cell function.
Explanation:
The Role of DNA Base Sequence in Hereditary Information
It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in the sequence of bases. Each DNA molecule consists of two strands forming a double helix, with the backbone made of phosphate and sugar groups, and nitrogenous bases inside. The base pairing is specific—adenine (A) always pairs with thymine (T), and guanine (G) pairs with cytosine (C). This complementary nature not only stabilizes the DNA structure but also allows for the precise replication of genetic information during cell division.
The information for building proteins is encoded in the sequence of these bases, often read in groups of three, known as codons, each specifying an amino acid in a protein. Thus, the sequence of bases along the length of a DNA molecule is fundamental in storing and transmitting hereditary information. This principle underlies all genetic functions, from the replication of DNA to the synthesis of proteins crucial for cellular function.
The powerful survival impulse that leads infants to seek closeness to their caregivers is called
Answer: Attachment
Explanation: Infants tend to be attached to their parents. For good reason because the parents usually treat kids very well during infancy, and its the only thing the infants understand or know.
In humans, a recessive allele of a gene on the X chromosome causes humans to be "colorblind." A colorblind XY man and an XX woman whose genotype is homozygous for normal color vision have children together. What percentage of their offspring are expected be colorblind?
Answer:
The answer is 0%.
Explanation:
If X⁻ represent the recessive allele that causes colorblind, and X⁺ represents the dominant allele, thus:
X⁻Y is the genotype of the colorblind man (he is carrier and he has the disease)
X⁺X⁺ is the genotype of the woman (she has normal vision and is not carrier)
When they have children together, the offspring will have the following genotypes:
X⁻Y x X⁺X⁺ = X⁻X⁺ ; X⁻X⁺ ; X⁺Y ; X⁺Y
Summarizing, they will be 50% X⁻X⁺ (women with normal vision, carrier) and 50% X⁺Y (men with normal vision, non carrier).
No child will have the disease because its expresses when the genotype is homozygous for colorblind allele (X⁻X⁻).
________, which is released from the pituitary gland, can potentially increase the height and weight of an individual to gigantic proportions, especially if administered during childhood and adolescence.
Answer:
Growth hormone
Explanation:
The growth hormone is released by somatotropic cells of the anterior pituitary gland. The growth hormone is an anabolic hormone and metabolic, tissue building and growth-promoting effects on the body. It stimulates the mobilization of fats, increases the blood levels of fatty acids to be used as flues for ATP production. It reduces glucose uptake and triggers glycogen breakdown.
In response to growth hormone, insulin-like growth factors are produced by the liver, skeletal muscle, bone, and other tissues which in turn facilitate growth by cell division, stimulated formation of collagen and deposition of bone matrix.
The growth hormone triggers cell division and cell enlargement, stimulates the growth of long bones by affecting the epiphyseal plate. It also stimulates the skeletal muscles to increase muscle mass. The overall effect is somatic growth. Its hypersecretion during childhood and adolescence can cause gigantism since the active epiphyseal plates promote excess bone growth.
A match between the DNA in a sample and the genomic DNA of a particular individual for a single tandem repeat site is not sufficient to establish identity. However, a mismatch is definitive. The primary reason is that:
Answer:
The mismatch is definitive, the primary reason is that, the DNA in the sample must match the original genomic DNA.
Explanation:
Tandem repeat takes place only when 'one or more nucleotide pattern is repeated' and it is 'adjacent' to each other. Mismatch indicates that the sample DNA is not the source for that Original DNA. If the sample is the actual source of the original genomic DNA, then it must be matched exactly.The DNA is matched with the sample DNA in the process of DNA fingerprinting. The mismatch of DNA is representative that the DNA sample does not belong to the original DNA.
What is DNA fingerprinting?DNA fingerprinting is the process of matching the DNA sample with the original DNA based on the tandem repeats.
The tandem repeat is the repeated unit of the nucleotides in the genetic material. When the sample DNA did not match the original DNA strands, it is the representation of mismatch.
The mismatch in the DNA sequence describes the absence of relation between the original and sample DNA.
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The image shows part of the humerous bone in different genera of primates.
Which statement is best supported by the observable structures of the different humerus bones?
A)
The primates lived in similar environments.
B)
The primates shared a common ancestor.
C)
The primates interbreed with similar organisms in a population.
D)
The primates had diets that consisted of similar types of foods.
Answer:
B) The primates shared a common ancestry.
Explanation:
I took a test EXACTLY like this a very long time ago, and since they look similar all the way down, passed down from generation to generation, this would be the obvious answer.
I am joyous to assist you anytime.
The primates shared a common ancestry.
What is Humerus Bone?The humerus is a long bone that extends from the shoulder and scapula (shoulder blade) to the elbow.
It is sometimes referred to as the upper arm bone. Proximal humerus fractures and humerus shaft fractures are the two categories used to classify humerus fractures.
A proximal humerus fracture can occur at different levels and with either a simple or comminuted fracture pattern. It typically happens close to the shoulder joint. On the other hand, a fracture of the humerus shaft is limited to the middle of the upper arm.
Therefore, The primates shared a common ancestry.
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You are confronted with a box of preserved grasshoppers of various species that are new to science and have
not been described. Your assignment is to separate them into species. There is no accompanying information as
to where or when they were collected. Which species concept will you have to use?
A) biological
B) phylogenetic
C) ecological
D) morphological
Answer:
The correct answer will be option-D
Explanation:
The morphological species concept is the concept which defines the species based on the morphological characters.
The species which can be grouped or organised on the basis of the morphological traits including the anatomy of the organisms arr called morphospecies and the concept is known as a morphological concept.
In the given question, since there is no information available for the collected grasshoppers, therefore, the biologist will classify the grasshopper species by studying the morphological characters of the species.
Thus, option-D is the correct answer.
Iodine is a yellowish solution. A starch solution is white. A starch solution turns purplish-black in the presence of iodine. If you wait a few hours, then add iodine to the beaker, what color would the beaker solution be?
Answer:
The correct answer will be- the color change will be observed and the solution will turn purplish-black.
Explanation:
Iodine test is performed to test the presence of the carbohydrates mainly starch.
The iodine solution is chemically called potassium iodide which forms a yellow solution. The potassium iodide solution forms a complex with a starch solution which appears a purplish-black color which shows the presence of the carbohydrates.
In the given question, if we add the iodine solution to the beaker after a certain point of time then it will still form a complex with the starch and thus beaker solution will appear darker in color.
Indicate if the conditions described would result in the development of a male or a female individual. SRY is a gene on the Y chromosome that is involved in initiating the development of the male phenotype in humans.
Final answer:
The presence and functionality of the SRY gene on the Y chromosome dictates the development of a male phenotype, leading to testis formation and testosterone secretion. Without a functional SRY gene, the embryo will develop female sex characteristics by default.
Explanation:
The conditions described would result in the development of a male individual if the SRY gene is present and functional. The SRY gene of the Y chromosome in embryonic germ cells produces the testis-determining SRY protein. This sets off a cascade of genetic activations that lead to the differentiation of the bipotential gonadal tissue into testes, which then secrete testosterone to further the development of male sex characteristics. Conversely, if the SRY gene is not present (as is the case for females with XX chromosomes) or it is mutated (as in conditions like Swyer syndrome), the individual will develop female characteristics.
A typical XY genotype with a functional SRY gene will inevitably cause an embryo to develop into a male. However, without the SRY gene or if a mutation occurs within it, the default development of the embryo will be a female. Cellular differentiation within the bipotential gonads will occur towards the formation of oogonia and primordial follicles in the ovary, rather than forming spermatogonia as it would in the presence of SRY.
What is the traditional name of the group of fungi that lack sexual reproduction?
Answer:
Deuteromycota fungi.
Explanation:
Deuteromycota which is known as imperfect fungi. It is a polyphyletic group of fungi, and they are not reproducing through the process of sexual reproduction. Most member of this phylum are leaves on land and few aquatic member are exceptions.
Reproduction in Deuteromycota are asexual means these fungi produce their spores with the help of asexual reproduction and this process is known as sporogenesis. Some example of this phylum are:
1) Penicillium camemberti.
2) Aspergillus oryzae.
3) Lecanicillium sp.
How are parasitic fungi different from other fungal symbionts?
Answer:
Explanation:
In contrast to other fungi symbionts for example: saprotrophic fungi, parasitic fungi attack living organisms, they invade them, penetrate their outer defense mechanism and take nourishment from the cytoplasm of living things and cause disease which may result to death of the host. Most disease causing or pathogenic fungi are parasitic to plants.
When mosquitoes are very abundant, purple martins flock to the area and specialize on them. When mosquito populations are not large, purple martins are similarly scarce and feed on other insects. This is an example of
A) community carrying capacity.
B) ecosystem carrying capacity.
C) exotic regulation.
D) density-independent regulation.
E) density-dependent regulation
Answer:
The correct answer is E) density-dependent regulation.
Explanation:
When the population growth rate is dependent on the density of a population then it comes under density-dependent regulation. Usually, when a population becomes denser the mortality rate becomes high in that population.
This regulation can occur due to factors like predation, disease, inter or intraspecies competition. So here when the density of the mosquitoes becomes high then purple martin flock to the area and specialize in them to gain nutrition which stabilizes the population of mosquitoes again.
Density-dependent regulation is more significant when the population density of a species increase. So the right answer is E.
During a routine physical examination on an older female client, a nurse notes that the client is 5 feet, 3/8 inches (1.6 m) tall. The client states, "How is that possible? I was always 5 feet and 1/2? (1.7 m) tall." Which statement is the best response by the nurse?
a) "The posture begins to stoop after middle age."b) "After menopause, the body's bone density declines, resulting in a gradual loss of height."c) "After age 40, height may show a gradual decrease as a result of spinal compression"d) "There may be some slight discrepancy between the measuring tools used."
Answer:
B
Explanation:
The nurse should tell the client that after menopause, the loss of estrogen leads to a loss in bone density, resulting in a loss of height.
You have an F2 generation derived from two true-breeding parents (AA and aa) with different characteristics for the same trait (determined by a single gene). What percentage of the recessive phenotype would you expect to be true breeding if they were self-fertilized?a. 0%.b. 33%.c. 67%.d. 25%.e. 100%
Answer:
The answer is letter B.
Explanation:
The percentage of the recessive phenotype would be 33%.
The eggs and larvae of marine animals tend to require water with more dissolved oxygen in it than the adults do. If water flows from a freshwater source into a salt water bay, what effect would this have on the population of marine animals?
Answer:The population will drop.
Explanation:
This is because the fresh water of high water potential will lower the solute potential of the salt water when they mixed up; to create a HYPOTONIC ENVIRONMENT for the larvae and the eggs.
Therefore, the higher water potential drives in water into the larva and egg membrane, down the water gradient by OSMOSIS. This made the cells and its organells to swell up until the elastic limit of the cell membrane is exceeded.
The products busted (eggs and larvae) once the elastic limit / stretching limit is exceeded leading to death of larvae and destrction of the egg, with eventual drop in population of the marine animals; since reproduction has been truncated( old animals are not replaced with young ones from the eggs and larvae.)
During photophosphorylation in plants, electrons flow through a series of carriers in the chloroplast. What is the ultimate donor of electrons, and what is the ultimate acceptor? What provides the energy to move those electrons?
The ultimate donor is H2O, and the acceptor, NADP+. The energy that drives this electron flow is from light.
The primary motor cortex for control of voluntary muscles is found in the
Answer: The primary motor cortex for control of voluntary muscles is found in the precentral gyrus of the frontal lobes.
Explanations:
The primary motor cortex is one of the important brain areas involved in motor function. It is found in the precentral gyrus of frontal lobes. It control voluntary muscles and generate impulses needed for movement execution.
Voluntary muscles are muscles that we can control consciously or we can control them at will and we can choose when we want to use them. They are also refers to as skeletal muscles and are attached to bones. The are majorly use for locomotion.
Answer:
I'm terrible at explaining so here's a screenshot
- Ripper
Explanation:
Which structure is indicated by letter D?
O Posterior dorsal root
O Anterior ventral root
O Peripheral nerve
O Dorsal horn
The structure indicated by letter D is the Dorsal horn.
Explanation:The structure indicated by letter D is the Dorsal horn. The dorsal horn is a region of gray matter within the spinal cord that receives sensory information from the body via the posterior dorsal root. It is involved in processing and transmitting sensory signals to the brain.
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In land mammals, the pelvic girdle is the point where the leg bones attach to the rest of the skeleton. Whales also have a small pelvic girdle. What type of evidence for common descent would include the whale's pelvic girdle?
Answer: comparative anatomy
Explanation:Darwin proposed that the forelimbs of human, bats and other creatures (whale) are similar. Although these Fore limbs are used for different purposes; he reasoned that similar forelimbs must have the same origin(Anatomy). He therefore concluded that these organisms should share same ancestors for evolution of modern Organism forms. He reasoned further that these modifications in body structures are required adaptations for survival in the competitive environment –survival of the fittest.
Charles Darwin was an evolutionist, a biologist of immense knowledge. He formulated the law of survival of the fittest
The whale's pelvic girdle serves as evidence for common descent, showing that whales evolved from land mammals that had four legs. The presence of vestigial structures, such as undeveloped hind legs, along with fossil records showing land animal characteristics in aquatic mammals like Rodhocetus, supports the shared ancestry of whales and land mammals.
Explanation:The Pelvic Girdle as Evidence for Common Descent
The presence of a pelvic girdle in whales provides evidence for common descent, indicating that whales and land mammals share common ancestors. In land mammals, the pelvic girdle is a crucial structure that attaches the legs to the axial skeleton and is adapted for supporting body weight and facilitating locomotion. Whales, despite being aquatic and not needing legs for locomotion, have vestigial pelvic bones. These structures are remnants from their four-legged land mammal ancestors, implying that whales evolved from such land-dwelling creatures and secondarily lost their hind legs. In particular, vestigial structures like the undeveloped hind legs in baleen whales, labeled as 'c' in skeletal diagrams, further support this evolutionary link. Additionally, the fossil record shows evidence, such as the aquatic mammal Rodhocetus possessing a type of ankle bone unique to land animals, corroborating the evolutionary transition from land to sea.
Organisms that use energy from sunlight or inorganic substances to make organic compounds
Answer:
Autotrouph
Explanation:
During recess, children are trying to balance a seesaw. If one side is too low, a heavier child will get off and be replaced by a lighter child; if one side is too high, a lighter child will be replaced by a heavier one. The children’s behavior is similar to our biological states as they try to create:______
Answer:
Homeostasis
Explanation:
Homeostasis is a process in the body where it tries to find a state of dysmic equilibrium
Answer:
Equilibrium.
Explanation:
Our body seeks to keep its internal functions in balance, even with variations in the environment in which it finds itself. This balance is called homeostasis and can be observed when our body tries to adapt to cold, hot days, reduced food and water, physical effort, among others.
An example of this can be seen in the question above, where an individual seeks to keep the two sides of a seesaw in balance.
Most Swiss starlings produce four to five eggs in each clutch. Those producing fewer or more than this have reduced fitness. Which of the following terms best describes this?
a. directional selection
b. stabilizing selection
c. disruptive selection
d. sexual selection
e. artificial selection
The human colon supports a large population of beneficial bacteria. How are these bacteria beneficial?
Two terms for the massive motor tracts serving voluntary movement are ________. Two terms for the massive motor tracts serving voluntary movement are ________. pyramidal and corticospinal extrapyramidal and rubrospinal supplementary and cerebellar-pontine segmental and nigrostriatal
Answer:
pyramidal and corticospinal
Explanation:
Motor pathways control body posture, reflexes and muscle tone, as well as conscious conscious movements. The best known motor route is the pira pyramid system ', which begins in the large pyramidal neurons of the motor cortex, continues along the pyramids of the brain stem and ends at or near the alpha motor neurons. This motor system is extraordinarily important in the clinic, because it is frequently affected by vascular accidents of the brain.
Lamont and his lab partner were filling out a worksheet on microorganisms. The table they filled in was about microorganisms that were a type of fungus. The boys had to add a third column and list each type of fungus as either helpful or harmful. Lamont wrote helpful for all five examples, but his partner said that was incorrect. Do you support Lamont or his partner? Explain.
A) Lamont is incorrect; athlete's foot is used to make food.
B) Lamont is correct. Fungi are helpful, not harmful. We eat fungi.
C) Lamont is incorrect. Two fungi on the list are harmful: salmonella and athlete's foot.
D) Lamont is correct. All five types of fungi in the table are helpful because they do beneficial things.
Answer:
C) Lamont is incorrect. Two fungi on the list are harmful: salmonella and athlete's foot.
Explanation:
The two examples "of what it does" gives you a hint in the table; Salmonella causes stomach illness and athlete's foot in a skin disease. These two hints shows that Lamont is wrong becuase the 2 fungi are harmful and not helpful. Lamont should have said 3 were helpful.
Answer:
C) Lamont is incorrect. Two fungi on the list are harmful: salmonella and athlete's foot.
Explanation:
Lamont is incorrect. Two fungi on the list are harmful: salmonella and athlete's foot. There are two examples of harmful fungi in the table, not just one. Salmonella causes stomach illness and athlete's foot in a skin disease.
A student travels to Brazil by boat on the Amazon River, without visiting the doctor prior to traveling for recommended vaccinations for travel to South America. The student becomes ill during the trip and is quarantined. Which of the diseases listed below does the student most likely have?
A) hantavirus
B) yellow fever
C) Ebola
D) Q fever
Answer:
The correct answer is B) Yellow fever
Explanation:
Yellow fever is a viral disease and this disease is spread by the bite of female Aedes aegypti mosquitoes that are found in Brazil and many other South American countries and the chances of getting yellow fever gets increase when anyone travels through amazon river.
The symptoms of yellow fever disease are fever, headache, back pain, nausea, and in some people it causes liver damage which results in yellowing of the skin.
So if anyone is traveling to Brazil in South America then he must be vaccinated for yellow fever which is also recommended by the WHO and CDC. Therefore yellow fever would be the disease that the student would most likely to have.
Final answer:
The student most likely has yellow fever, which is caused by the yellow fever virus transmitted by mosquito vectors.
Explanation:
The student most likely has yellow fever.
Yellow fever is caused by the yellow fever virus and is transmitted to humans by mosquito vectors. It occurs primarily in tropical and subtropical areas in South America and Africa. The virus can be transmitted from infected monkeys to humans in tropical jungle regions, or between humans in urban areas.
Prevention of yellow fever includes the use of mosquito netting, window screens, insect repellents, insecticides, and vaccination for those traveling to endemic areas.