Answer:
the answer is a
Explanation:
you can read twice. it show the 5 year emily have longer attention. thay why he see 3 year children go around
Which of the following is true of crossing over? It involves the exchange of chromosome segments between homologous chromosomes. It occurs in meiosis I. It increases genetic variability. All of the choices are correct.
Answer: All of the choices are correct.
Explanation:
Meiosis is a type of cell division of the nucleus that occurs in cells that will give rise to gametes (egg or sperm). These are haploid cells (n), that is, they possess only one chromosome of each of the pairs (23 in total). Through meiosis from a diploid cell (2n), four haploid cells are obtained, thanks to two successive divisions called meiosis I and meiosis II. Both comprise prophase, metaphase, anaphase and telophase.
Homologous chromosomes are a pair composed of a paternal and a maternal chromosome. They have the same DNA sequence arrangement from one end to the other, but different alleles. These chromosome copies have the same genes at the same loci where they contribute tips along each chromosome that facilitate a pair of chromosomes to align correctly with each other before they separate during meiosis. Sister chromatids are those that make up a chromosome after duplication of the genetic material.
The homologous chromosomes of maternal and paternal origin, mate and this process is called "synapsis" and form what is known as a tetrad or bivalent chromosome, giving the impression that it is a chromosome with four chromatids. In these tetrads, junctions called chiasmata are formed, areas in which both homologues exchange genetic material or genes, a process known as crossing-over. The chiasmata allow the chromosomes to be held together until their separation in anaphase l. So, genetic recombination is the process by which a segment of genetic material from a maternal chromosome is cut and then joined to a paternal chromosome (or vice versa) during prophase I of meiosis. So it happens between non-sister chromatids of a paternal and a maternal chromosome.
After crossing over, the homologous chromosomes are arranged randomly at the cell's the equator of the cell at random (methaphase), facing each other, still united in the areas where crossing over occurred. Each chromosome is associated with a meiotic spindle fiber of the meiotic spindle and they are pulled along the meiotic spindle and driven toward the respective poles (anaphase). The chromosomes are now arranged at the poles and the reorganization of the nuclear envelope and the nucleolus begins. Finally, cytokinesis occurs and the rearrangement of cellular components and reorganization of the cytoskeleton. As a result of meiosis I, 2 haploid cells are obtained and then meiosis II occurs, where the sister chromatids are separated, generating two more cells (a total of 4).
Genetic variability is generated because the gametes produced during meiosis will not inherit the same chromosomes as the mother cell, but due to crossing over, the inherited chromosomes will be genetically different.
Which structures allow lycophytes to grow bigger than mosses and liverworts?
A. gametophytes and sporophytes
b. xylem and phloem
C. haploid and diploid
D. roots and stems
The structure that allows lycophytes to grow bigger than mosses and liverworts is xylem and phloem which is option B
Lycophytes are spore bearing vascular plants. Being a vascular plant, they possess vessels ( vascular tissues) which include:
ylem: this is used for conducting water usually from the root to the rest of the plant partsPhloem: this is the vascular tissue that is used to conduct food( sugar) produced in the leaves of plants to other parts of the plant.The possession of the vessels makes the lycophytes appear bigger.
Mosses and liverworts belongs to the plant phylum Bryophyta. They do not have any vascular tissues that can be used to conduct water and food. This restricts their size.
Therefore, the structure that allows lycophytes to grow bigger than mosses and liverworts is xylem and phloem
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Answer:
xylem and phloem
Explanation:
Lycophytes have specialized tissue that transports nutrients and provides structural support.
100 POINTS!!!!!! Help FAST!!!!!!!!!!!!!!The picture below shows the bone structures of human, cow, and horse.
Picture shows similar bone structures of human, cow, and horse.
Based on the diagram, which of these statements is correct about humans, cows, and horses?
They have developed from the same organism.
They have completed their evolutionary process.
Humans have evolved from several ancestors.
Horses have evolved from cows and humans.
Answer:
option A they have developed from the same organism
Explanation:
Organs of animals (belonging to different species) which have similar structure but different functions are homologous organs. Such organs have evolved from the same ancestors , however their function are different.
For example – wings of bats, limb of human etc.
Here in this case also the bone structures of human, cow, and horse are same but their functions are different, thus they are homologous organs and hence they have evolved from same ancestors.
The correct answer is option A
Answer:
"They have developed from the same organism."
Witch of the following is an example of a good hypothesis? A. The vinegar is the acid and the soap is the base. B. I think the glow sticks will be brighter in the hot water. C. When placed in hot water , sugar cubes will dissolve more slowly then granulated sugar. D. Hot water makes things disk faster.
List the reactions of glycolysis that: _________
a. are energy-consuming (under standard state conditions).
b. are energy-yielding (under standard state conditions).
c. consume ATP.
d. yield ATP.
e. are strongly influenced by changes in concentration of substrate and product because of their molecularity.
f. are at or near equilibrium in the erythrocyte
Answer:
b. are energy-yielding (under standard state conditions).
d. yield ATP.
Explanation:
The reactions of glycolysis produces the ATP molecules from the breakdown of glucose molecule. Glycolysis produces 2 molecules of ATP, 2 molecules of NADH, and 2 molecules of pyruvate: Glycolysis breakdown glucose with the help of oxygen produces energy in the form of ATP, NADH, and pyruvate so e can conclude that glycolysis are energy-yielding process for the cell.
Spermatogenesis is a process in which the tests produce
red blood cells
sperms
white blood cell
eggs
Answer:
Produce sperms.
Explanation:
This occurs in three stages; proliferation and spermatogia differentiation, meiosis, spermeogenesis.
Answer:
._.xd
Explanation:
xd
In large populations, small fluctuations in survivorship or reproduction among individual organisms are unlikely to affect allele or genotype frequencies in the population.
a. True
b. False
Answer: True.
Explanation:
A population is defined as the set of individuals that inhabit a given geographic area. A population has a certain allele frequency, which is the measure of the relative proportion of alleles in a given population, expressed as a percentage or unit. It is estimate using the number of times the allele is found in a locus and dividing it by the total number of alleles. While the genotypic frequency refers to the number of times that each of the genotypes generated by the two-by-two combinations of the alleles involved in the locus under study appears in relation to the total number of genotypes (which will be equal to the total number of individuals included in the study).
The population can be increased or decreased according to the birth and death rates. Generally, unless specific alterations occur, such as the spread of a disease, immigration, emigration, natural disasters, and others, the size of the population will remain constant. This means that the birth rate is quite similar to the death rate. And the larger the population, the more difficult it is to disturb this balance between births and deaths. So if small fluctuations in survival or reproduction occur between individuals, it is unlikely that this will affect the frequency of alleles and/or genotypes. This is explained using the Hardy-Weinberg principle states that the genetic composition of a population remains in equilibrium as long as no mutation occurs, and nor natural selection nor any other factor acts. After a generation of random mating, the frequencies of the genotypes of a locus are fixed at an equilibrium value. Then, the genetic variation in a population will remain constant from one generation to the next in the absence of extreme disturbing factors such as those mentioned above (diseases, natural disasters, and others).
Note that for this principle to be fulfilled, the population must be diploid (have two alleles of each gene), must reproduce sexually in a random manner, and must be large enough to minimize the effect of genetic drift (random fluctuations in allele frequencies from one generation to the next, due to random events that can cause certain traits to become dominant or disappear from a population).
The area within the lungs where gas exchange occurs is called?
Answer:
The alveoli are the sites of gas exchange; they are located at the terminal regions of the lung and are attached to the respiratory bronchioles. The acinus is the structure in the lung where gas exchange occurs. The sac-like structure of the alveoli increases their surface area.
How would the DNA of a fish compare to the DNA of a lion
Answer:
The double helix can be found almost everywhere in DNA. AGTC is found in lions, humans, and fish. The double helix is the most stable structure for maintaining genomic integrity in AGTC. The gene structures (that is, sequence) differ, as do promoters and other elements, but the DNA structure remains the same.
Complete the comparison of the metabolic pathways leading to thymine in DNA and thymine as a modified base in tRNA.
Thymine in DNA occurs as the result of thymidylate synthase creating _______________ , which then undergoes ____________ to ____________, then to __________, and incorporated into DNA by ___________.
Answer:
The question is incomplete, the complete question is as follow:
Thymine in DNA occurs as the result of thymidylate synthase creating _______, which then undergoes _______ to _______, then to _______, and incorporated into D N A by _______. Thymine in tRNA arises ________, by an S-adenosylmethionine-dependent _______ of a ______ residue in RNA.
Answer:
Thymine in DNA occurs as the result of thymidylate synthase creating dTMP, which then undergoes phosphorylation to dTDP, then to dTTP, and incorporated into DNA by DNA polymerase. Thymine in tRNA arises posttranslationally, by an S-adenosylmethionine-dependent methylation of a UMP residue in RNA.
Explanation:
Thymidylate synthase is a key enzyme that catalyzes the synthesis of 2′-deoxythymidine-5′-monophosphate (dTMP) from 2′-deoxyuridine-5′-monophosphate (dUMP). This enzyme catalyzes the addition of a phosphate group (phosphorylation) of dTMP in order to form thymidine 5'-diphosphate (dTDP). Once synthesized, dTMP can be metabolized to deoxythymidine triphosphate (dTTP), which is a precursor for DNA biosynthesis. On the other hand, transfer ribonucleic acid (tRNA) is methylated after the molecule is synthesized. The transfer of the methyl group is catalyzed by an S-adenosylmethionine–dependent methyltransferase that catalyzes the methylation of uridine monophosphate (UMP) using SAM (S-adenosylmethionine) as the methyl donor.
What is the effect of alcohol administration on the frequency of Daphnia heart contractions and how does this effect of alcohol change with the dose of alcohol applied?
Answer:
to prevent bacteria and viruses
Writing Assignment
One of the main functions of connective tissue is to integrate
organs and organ systems in the body, Discuss how blood
fulfills this role.
Answer:
Major functions of connective tissue include: 1) binding and supporting, 2) protecting, 3) insulating, 4) storing reserve fuel, and 5) transporting substances within the body .Blood integrates organs and organ systems by transporting and exchanging fluid with various organs and organ system to allow them to function and work properly allowing the organism to survive
Is the introduction of contaminants into a natural environment that causes instabilitying organisms and the physical environment
interact in an immense and complicated web of relationships.
O a Chemicalsubstances
Ob pollution
Oc. Environment
Answer:
ℴℴℴ
Explanation:
ℯℯ ℴ ℯ ℊ
Which is another name for observation?
Answer:
I would say hypothesis is what we use for science as a guess, but also monitoring is a good one.
Explanation:
Another name for observation is inspection.
hormones stimulate certain endocrine glands to secrete hormones.
Answer:
hope its helps you
Explanation:
please like and mark brainlis
How are rivers and streams able
to keep algae from growing?
Plz help
Answer:
answer is A just did it on my acellus
Explanation:
The correct answer is option (A) the running water will sweep the algae downstream and keeps it from growing.
What is algal bloom?
The rapid increase in production of algae in freshwater and marine water system is called algal bloom. It is also known as the discoloration of water from the algal pigment.What causes algal bloom?
Excessive nitrogen and phosphorus cause overgrowth of algae.The overgrowth of algae consumes oxygen and blocks sunlight from underwater plants. When the algae eventually dies, the oxygen in the water is consumed.As the river and streams are always flowing it will sweep the algae which will prevent it from growing further.
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Whose argument is stronger regarding the SAC curves and the LAC curve? A. The draftsman since the lowest point on each SAC curve will have a horizontal tangent line which only occurs at the lowest point on the LAC. B. Jacob Viner since the SAC curves can be adjusted slightly and still keep their U-shape in a way that makes their lowest points end up on the LAC curve. C. Jacob Viner since the long-run average cost curve must be composed of the lowest points on any individual short-run average cost curve. D. The draftsman since, while it is true that the points of tangency of the SAC curves with the LAC curve are at each SAC curve's minimum, it is impossible to illustrate it accurately.
NB: This is a business question, not biology.
Answer:
SAC (Short-run Average Cost) and LAC (Long-run Average Cost)
The stronger argument regarding the SAC (Short-run Average Cost) curves and the LAC (Long-run Average Cost) curves is:
A. The draftsman since the lowest point on each SAC curve will have a horizontal tangent line which only occurs at the lowest point on the LAC.
Explanation:
The costs of all factors of production become variable in the long run. But in the short-run, some costs are variable, and some are fixed. When the producer starts operating over the long run period, it can then operate without the constraints imposed by the presence of the fixed-cost factors. Therefore, in the long run, the average cost (LAC) is equal to the short-run average cost (SAC) because there is an unconstrained minimum average cost at all output levels.
As the human population grows, some minerals in everyday products could
become scarce. Which of the following is the best way to address this
problem?
Answer:
Explore uses of more plentiful minerals.
Explanation:
Because the use of more can get us more items that can grow the population and interest.
How does the use of greywater differ from water reclamation?
a.
If collected separately, greywater can be used for certain applications without treatment.
b.
Greywater use is more costly than water reclamation.
c.
Water obtained from water reclamation processes can be used for drinking, while greywater cannot.
d.
Greywater has been mixed with sewage while water used in water reclamation is derived from cleaning water.
Greywater can be used for certain purposes without being treated if it is collected separately.
What distinguishes reclaimed water from gray water?Recycled water—also known as "reclaimed water"—is treated, regulated water that can be used only in certain categories. Graywater is untreated wastewater from domestic sources that can be used under certain regulatory restrictions (with the exception of waste from kitchen sinks, dishwashers, and toilets).
What distinguishes desalination from water reclamation?Desalination is a process that transforms seawater or brine water into drinkable water by removing dissolve salts. Additionally, reclaiming water is converting waste water.
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Why might an individual with AIDS have difficulty fighting off otherwise harmless infections? please answer!! last question I have!!!
Answer:
The HIV virus that causes AIDS kills T-cells. T-cells are responsible for fighting off infections. So someone with AIDS has a reduced number of T-cells and are unable to fight off infections that are harmless to other individuals.
A. the influence of environment on the expression of a particular genotype. B. the expression of a dominant phenotype in a heterozygote. C. the expression of one gene masking the effects of another gene. D. quantitative traits that diminish or intensify a particular phenotype. E. the increased expression of a particular trait when a hybrid species is formed.
The question is incomplete, the complete question is;
Penetrance and expressivity are related to
A. the expression of a dominant phenotype in a heterozygote.
B. the increased expression of a particular trait when a hybrid species is formed.
C. the expression of one gene masking the effects of another gene.
D. quantitative traits that diminish or intensify a particular phenotype.
E. the influence of environment on the expression of a particular genotype.
Answer:
the influence of environment on the expression of a particular genotype.
Explanation:
In genetics, we define penetrance as the proportion of individuals in a given population carrying a particular gene/allele which leads to the expression of the particular trait associated with that gene/allele.
Expressivity is defined as the degree of expression of a given phenotype by individuals who possess a particular genotype. Expressivity shows the extent of variation in expression of genes by individuals having a particular genotype.
Both penetrance and expressivity has to do with the influence of environment on the expression of a particular genotype.
What is the name of a type of nucleic acid that is used for signalling in cells
Answer:ribonucleic acid
Explanation:
1.Explain how is small intestine designed to absorb digested food.
2.Write two differences between the nutrition in amoeba and human beings.
3.Fungus can be harmful and useful. Give an example showing both of these traits of fungus.
Answer:
Similarity:
Amoeba and human beings require the same nutrients like carbohydrates, proteins, and fats for their growth and survival.
Difference:
1. Mode of Nutrition:
Amoeba is unicellular and microscopic, which makes it an organism that uses the Holozoic mode of nutrition. It ingests food through its cell membrane and feeds on other tiny organisms like bacteria, algae, and protozoans. On the other hand, human beings are multicellular organisms and use saprophytic and holozoic modes of nutrition. They ingest complex food materials that are broken down into simpler nutrients.
A team of researchers is investigating a new carbon-rich molecule important to life. They find evidence for the
presence of a carbon-carbon double bond in the molecule. This observation means that the new molecule likely
exists as which of following?
A. an aliphatic hydrocarbon
B. a hydrocarbon ring
C. both cis and trans isomers
Answer:
i think they found a hydrocarbon ring
What process creates new cells?
A. cell division
B. cell metamorphosis
C. cellokinesis
Answer:
A. cell division
Explanation:
What happens inside the mitochondria?
A. photosynthesis
B. blood circulation
C. cellular respiration
Which mineral is produced when two atoms of iron chemically combine with three atoms of
oxygen?
1. garnet
2. pyrite
3. magnetite
4. hematite
The natural mineral form of iron oxide is called hematite The mineral, which contains 70% pure Fe, ranges in color from metallic dull to vivid black to steel-gray. Thus, option D is correct.
What atoms of iron, chemically three atoms of oxygen?Oxides of many significant metals are common. Iron oxides include hematite (Fe2O3), which has a ratio of two iron atoms to three oxygen atoms, and magnetite, which has a ratio of three iron atoms to four oxygen atoms. The most magnetic mineral is magnetite.
On the surface of the Earth, it is the mineral that is most common. There are numerous other applications for hematite.
It is employed in the production of pigments, polishing, heavy media separation, jewelry making, and home energization. In addition to these, it has therapeutic properties.
Therefore, hematite mineral is produced when two atoms of iron chemically combine with three atoms of oxygen.
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After an accident, David has trouble moving his left arm and feeling things with his left fingers. The doctor tells him this is due to brain damage in his cerebral cortex. in which hemisphere is davids brain damage likely to be
One of the distinguishing characteristics of nervous tissue is how difficult it is to repair damage to nervous tissue. Explain factors limit neurogenesis in the CNS of adults, why is it so hard to repair a damaged nerve
Answer:
Inhibitory influences from neuroglia, and the absence of growth-stimulating cues.
Explanation:
Neurogenesis in adults is limited by Inhibitory influences from neuroglia, mainly from oligodendrocytes, and the absence of growth-stimulating cues that are present during fetal development. It is so hard to repair a damaged nerve because nerve cell like other cells can't divide and increase in number, they can't renew themselves. Due to no division, the nerve cells does not increase in number and therefore can't repair themselves.
Which of these methods that aids in the movement of ions or molecules across a cell membrane requires the use of energy which is supplied by ATP molecules?A. Osmosis.B. Reverse diffusion.C. Passive transport.D. Active transport.E. Facilitated diffusion.
Answer:
D. Active transport.
Explanation:
Active transport is the method that uses the ATP's energy to move ions and molecules from one side to the other of the membrane. The elements move from a place of lower concentration to one of a higher concentration. They move against their concentration gradient, which is why they need the energy to do it. There are two types of active transport, primary and secondary.
The primary active transport is ion pumps that hydrolyze ATP using one of the phosphates of the ATP to change the pump's shape and move the elements against their concentration gradient. It uses the ATP's energy directly.
The secondary active transport does not use ATP directly. It uses the electrochemical gradient that the primary transport had created when hydrolyzing ATP to transport the ions and molecules.
