Answer:
Gymnosperms (pine trees)
Explanation:
Gymnosperms, or trees that reproduce using cones instead of flowers, are the primary plane life in a coniferous forest.
According to the intermediate disturbance hypothesis,
A. species diversity is highest when disturbance is rare.
B. species cannot colonize after intermediate disturbance.
C. competition eliminates species when disturbance is rare.
D. competition eliminates species when disturbance is common.
E. none of the above
Answer:
C. competition eliminates species when disturbance is rare.
Explanation:
Intermediate disturbance hypothesis aims to explain the species diversity in an area. According to it, intermediate level of disturbance is required to maximize species diversity.
In case of high level of disturbance like deforestation or forest fire, all species are at risk of going extinct. In case of low level of disturbance, interspecific competition for resources increases due to which one species becomes dominant and another nearly extinct, thus reducing species diversity. Hence, an intermediate level of disturbance is required to maximize species diversity.
What do you think causes the tidal bulges to form?
Tidal bulges are created by the gravitational interaction between the Earth and the Moon, resulting in a differential force that affects the Earth's oceans. This results in two tidal bulges - one on the side facing the moon and another on the opposite side.
Explanation:Tidal bulges are primarily formed due to the gravitational interaction between the Earth and the Moon. This interaction causes a differential force which affects the water in the Earth's oceans. On the side of the Earth facing the Moon, this differential force makes the water flow towards it creating one tidal bulge.
On the opposite side, gravitational force is weaker and the inertia of the water causes it to bulge out, forming the second tidal bulge. Effects from the Sun, rotational forces from the Earth, and the shape of the coastlines and ocean basins can further complicate tidal patterns.The tide-raising forces, acting over a number of hours, produce motions of the water that result in measurable tidal bulges in the oceans.
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Replication of the lagging strand of dna is accomplished by repeatedly making __________ followed by 1
Answer:
The correct answer is "short RNA primers; Okazaki fragments".
Explanation:
The missing information of this question is as follows:
"Replication of the lagging strand of dna is accomplished by repeatedly making __________ followed by 1,000-2,000 nucleotide segments called __________"
The correct answer is "short RNA primers; Okazaki fragments".
DNA replication always occurs from 5' to the 3' end, in what is known as the directionality or the end-to-end chemical orientation in molecular biology. This fact makes difficult the synthesis of the lagging strand of DNA. In order to achieve this short RNA primers are bound to segments of DNA (serving as the 5' end available for the DNA polymerase to synthesize), which leads to the discontinuous synthesis of Okazaki fragments that are later linked together by the enzyme DNA ligase.
What is phosphorus ?
Answer:
A chemical element with the symbol P and atomic number 15.
Explanation:
Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Earth.
Handedness:a.reflects the greater capacity of one side of the brain to carry out skilled motor action. b.is evident in a wide range of skills from birth. c.is a heritable trait, especially for left-handed people. d.is strongest for simple, rather than complex, skills.
Answer: a.
Explanation:
The proficiency to be more professional and confident using one hand instead of the other for activities such as writing and throwing a pitch is called handedness.
Handedness begins to develop before birth. Handedness is inheritable and evident from early childhood. handedness is related to variations between the brain's right and left halves (hemispheres). The the left hemisphere regulates the action of right side of the body while right hemisphere controls movement on the left side of the body.
So in handedness, one half of the brain regulates more skilled motor action.
Hence, teh correct option is a.
When skin cells have third-degree burns, skin grafts are used. What is the benefit to using skin grafts?
They provide a permanent layer of skin for the burned area.
They protect the burn from infection.
They provide a shorter healing time for the burned area.
Answer:
The answer is B. They protect the burn from infection.
Hope this helps (:
Skin grafts are beneficial in treating third-degree burns by providing a permanent skin layer, protecting the burn from infections, and shortening the healing time. Option 1, 2 and 3.
Explanation:The benefit of using skin grafts in treating third-degree burns is manifold. Firstly, skin grafts provide a permanent layer of skin for the burned area, which helps restore the skin's natural barrier function. Secondly, they protect the burn from infection, since burnt skin is highly prone to infections that can lead to severe complications. Thirdly, they contribute to a shorter healing time for the treated area. Timely application of skin grafts can reduce the likelihood of prolonged wound healing, which in turn can minimize scarring and improve functional and cosmetic outcomes.
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Here are some biology questions pls help ASAP. 15Pts question
Sickle cell anemia is a disease where red blood cells become thin and elongated. If a person has one copy of the sickle cell allele, half of their red blood cells will be misshapen. In this way, the allele is codominant, since both normal and sickled shapes are seen in the blood.
If two parents present the heterozygous phenotype for sickle cell have an offspring, what is the probability of their child having sickle cell?
A. Their offspring will have a 0% chance of having sickle cell.
B. Their offspring will have a 25% of having the homozygous dominant genotype, resulting in sickle cell.
C. Their offspring will have a 75% chance of having sickle cell.
D. Their offspring will have a 25% chance of having the heterozygous genotype, resulting in sickle cell.
One parent is heterozygous for the sickle cell trait, and the other is homozygous recessive. What is the probability of each offspring displaying each genotype - expressed as a ratio?
A. 1 homozygous recessive : 0 homozygous dominant: 1 heterozygous
B. 3 homozygous recessive : 1 homozygous dominant: 0 heterozygous
C. 1 homozygous recessive : 1 homozygous dominant: 2 heterozygous
D. 0 homozygous recessive : 1 homozygous dominant: 1 heterozygous
3. In some cattle the genes for brown hair and for white hair are codominant. Cattle with alleles for both brown and white hair, have both brown and white hairs. This condition gives the cattle a reddish color, and is referred to as Roan. What is the probability, expressed as a fraction, of a red cow and a roan bull having a roan offspring?
A. 1/4
B. 1/2
C. 3/4
D. 4/4
4. In Andalusian fowls, black individuals (BB) and white individuals (bb) are homozygous. A homozygous black bird is crossed with a homozygous white bird. The offspring are all bluish-gray. What is the probability of each phenotype, expressed as a ratio, of two heterozygous individuals?
B
b
B
BB
Bb
b
Bb
bb
A. 1 black : 1 white : 2 bluish-gray
B. 3 black : 1 white : 0 bluish-gray
C. 3 black : 0 white : 1 bluish-gray
D. 2 black : 1 white : 1 bluish-gray
5. In snapdragon flowers the color of the flower is determined by an incompletely dominant gene. If you cross a purebred white snapdragon with a pink snapdragon, what is the likelihood, expressed as a fraction, of an offspring with the heterozygous genotype?
A.1/4
B. 1/2
C. 0/4
D. 3/4
6. A genus of shrimp Neocaridina can be any color from mottled brown to red. The color of the shrimp is determined by the genes at three loci A,B, and C, each loci has two alleles A or a; B or b; and C or c. The color of the shrimp is determined by the total number of dominant genes, the more dominant genes the darker the shrimp. What genotype below would display the darkest phenotype?
A. AAbbCC
B. AaBbCc
C. aaBBCC
D. AABbCC
7. Skin color for a species of lizards is polygenic with individuals with a fully recessive genotype being green and those with a fully dominant genotype being brown. In an environment the selective pressures favor individuals with a green phenotype, which genotype below would be best fit to the given environment?
A. RRssTT
B. rrSSTt
C. rrSstt
D. RRSSTT
Answer:
1. B - Aa x Aa = 25% chance AA, which is the only genotype that results in sickle-cell. Aa is called "sickle-cell trait'; it isn't the full disease.
2. A - Aa x aa = we know will produce no homozygous dominant
3. B - RR x Rr = 1/2 chance of Rr (same problem as #5)
4. A - Bb x Bb = 1:2:1 ratio
5. B - WW x Ww = 1/2 chance of Ww
6. D - AABbCC has 5 dominant alleles, which is the most out of the four options
7. C - the one with the fewest dominant alleles will be the most green and the most successful in the environment
Which of the following is not true of the reproductive system?
Group of answer choices
It produces and transports gametes.
It includes both internal and external reproductive structures.
It stores and nourishes gametes.
It produces GH and ADH.
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Question 24 pts
Fertilization of an ovum most often occurs in the
Group of answer choices
oviduct or fallopian tube
ovary
uterus
vagina
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Question 34 pts
The primary hormone responsible for development and maintenance of female sex characteristics is
Group of answer choices
estrogen
progesterone
gonadotropin
LH
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Question 44 pts
The layer of the uterus from which tissue is sloughed during menstruation is the
Group of answer choices
parietal peritoneum
endometrium
myometrium
None of the above.
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Question 54 pts
The cremaster muscle raises and lowers the testes to
Group of answer choices
protect them from trauma
to maintain proper temperature for sperm production
to help move sperm from the testes into the seminal vesicles
None of the above. The cremaster muscle does not raise and lower the testes.
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Question 64 pts
The period of pregnancy during which the developing fetus rapidly increases in size is the ___ trimester.
Group of answer choices
first
second
third
All of the above.
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Question 74 pts
The period of pregnancy during which the basics of all major organ systems appear is the ___ trimester.
Group of answer choices
first
second
third
All of the above.
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Question 84 pts
The last major organ(s) to mature during fetal development is/are the
Group of answer choices
brain
lungs
heart
stomach & intestines
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Question 94 pts
After undergoing meiosis, an egg and sperm each contain ___ chromosomes, while a developing fetus contains ___.
Group of answer choices
13, 26
23, 23
23, 46
46, 92
The following questions are answered below.
Explanation:
1. The following statement is not true for the reproductive system is it includes both internal and external reproductive structures.
2. Fertilization of ovum most often occurs in the oviduct or fallopian tube.
3. The primary hormone is responsible for development and maintenance of female sex characteristics is estrogens.
4. The layer of the uterus from which tissue is sloughed during mensuration is the endometrium.
5. The cremaster muscle raises and lowers the testes to maintain proper temperature for sperm production.
6. The period of pregnancy during which the basics of all major organ systems appear is the first trimester.
7. The last major organ(s) to mature during fetal development is/are the brain.
8. After undergoing meiosis, an egg and sperm each contain 23 chromosomes, while a developing fetus contains 46.
Final answer:
The reproductive system is responsible for the production and transport of gametes, but it does not produce hormones like GH and ADH. Fertilization typically occurs in the fallopian tube, estrogen is key for female characteristics, the cremaster muscle regulates testes temperature, the fetus grows rapidly in the third trimester, organ systems appear in the first trimester, the lungs mature last, and post-meiosis, gametes carry 23 chromosomes each, combining to form a zygote with 46.
Explanation:
The reproductive system performs critical functions for the perpetuation of species, including humans. Let's examine the questions about it sequentially:
The incorrect statement about reproductive system is "It produces GH and ADH." These hormones are actually secreted by the pituitary gland and are not directly related to reproductive processes.Fertilization of an ovum most often occurs in the "oviduct or fallopian tube."The primary hormone responsible for development and maintenance of female sex characteristics is "estrogen."The layer of the uterus from which tissue is sloughed during menstruation is the "endometrium."The cremaster muscle raises and lowers the testes "to maintain proper temperature for sperm production."The period of pregnancy during which the developing fetus rapidly increases in size is the "third trimester."The period of pregnancy during which the basics of all major organ systems appear is the "first trimester."The last major organ(s) to mature during fetal development is/are the "lungs."After undergoing meiosis, an egg and sperm each contain "23 chromosomes," while a developing fetus contains "46."
During the summer, when the land is brown and the grass is green, the population of mice decreases because mice are easily spotted by the organisms that eat them.
How would this change affect the food web? Check all that apply.
It will increase the grass population.
It will increase the fox population.
It will decrease the shrew population.
It will decrease the snake population.
It will increase the grasshopper population.
Answer:
the REAL CORRECT answers are
A) it will increase the grass population
D) it will decrease the snake population
E) it wil increase the grasshopper population.
hope this helps.
What is humidity?
a. A measure of how warm it is outside
b. A measure of how much water vapor there is in the air
c. A measure of how many clouds there are in the area
d. A measure of how much rain there is in the upper atmosphere
Answer:
A measure of how much water vapor there is in the air.
Explanation:
Dampness, especially that of the air.
The amount of water vapour in the air.
Hope it will help you :))
Answer:
C
Explanation:
Mark said that a category 5 hurricane causes more damage than an EF-1 tornado. Mary said that an EF-1 tornado causes more damage than a category 5 hurricane. Make a decision as to who has the correct statement and justify your decision in two or more complete sentences.
Answer
the answer would be... Mark!
Explanation:
Due to the Enhance fujita scale (EF) an EF 1 would do minor damage resulting in some downed trees, power lines, and some mobile houses off their structures. On the category side though a category 5 hurricane would cause catastrophic damage. If you look back to EF1 tornadoes and category 5 hurricanes you can see the damage it has done, a giant difference.
Have a great day (or night!)
Mark has the correct statement that a category 5 hurricane causes more damage than an EF-1 tornado.
What are hurricanes and tornado?Hurricanes and tornadoes are both natural disasters, but they differ in their size, duration, and destructive power. A category 5 hurricane is the most severe hurricane on the Saffir-Simpson scale and has sustained winds of 157 mph or higher, while an EF-1 tornado is a relatively weak tornado with wind speeds of 86-110 mph.
Hurricanes also have a much larger diameter and longer duration than tornadoes, which can cause more widespread damage over a larger area.
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Mendel's law of independent assortment has its basis in which of the following events of meiosis I?
alignment of pairs of homologous chromosomes along the middle of the cell
synapsis of homologous chromosomes
crossing over of homologous pairs of chromosomes
the division of cells at telophase
Explanation:
Alignment of pairs of homologous Mendel's law of independent assortment, expresses that allele sets separate during the arrangement of gametesThis implies qualities are transmitted to offspring independently of one anotherDevelopment of random combinations of chromosomes in meiosis and of qualities on various sets of homologous chromosomes by the entry as indicated by the laws of probability of one of every diploid pair of homologous chromosomes into every gamete independently of one another pairMendel's law of independent assortment has its basis in the alignment of pairs of homologous chromosomes along the middle of the cell.
WHAT IS MENDEL'S LAW OF INDEPENDENT ASSORTMENT:Mendel's law of assortment states that alleles of a gene segregates independently into gametes. According to Mendel, the segregation of alleles into gametes does not interfere the segregation of another. The alignment of homologous chromosomes during the metaphase stage of meiosis 1 ensures that alleles segregate independently.Therefore, Mendel's law of independent assortment has its basis in the alignment of pairs of homologous chromosomes along the middle of the cell.
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A nucleotide-sugar coenzyme involved in carbohydrate metabolism (UDP-glucose) is formed when UTP reacts with a glucose molecule. More UTP is made available for additional reactions by the transfer of a phosphate group from:________.
a. ATP.
b. UDP.
c. ADP.
d. UTP.
e. Another carbohydrate.
Answer:
b. UDP
Explanation:
Uridine diphosphate glucose (UDP) is a nucleotide sugar involved in galactose metabolism. In this reaction, the galactose 1-phosphate uridylyltransferase (GALT) enzyme transfers a phosphate group from UDP-glucose to galactose 1-phosphate in order to convert galactose into glucose
Within a population extreme, phenotypes are often observable within the same species. Which of the following explains why sexual selection often causes genetic variations that express extreme phenotypes within a population?
Genetic variation from sexual reproduction produces new phenotypes.
Only genes for favorable traits are passed on to future generations.
Only the intermediate genes are allowed to be passed on to offspring.
Organisms reproduce with closely related species, which results in extreme phenotypes.
Explanation:
Genetic variation from sexual reproduction produces new phenotypes Sexual reproduction promotes hereditary variety by producing distinctive quality mixesMeiosis is the process by which sex cells or gametes are developedThe genetic recombination of qualities likewise occurs during crossing over or the swapping of quality portions in homologous chromosomes during meiosis Phenotypes can be caused about by qualities, ecological components, or a blend of bothPhenotypic variety, at that point, is the variability in phenotypes that exists in a populationDr. Graham exposes rats to a vanilla scent prior to receiving a food pellet in the left corner of their cage, but provides no food after exposure to a lemon scent. After several trials, upon smelling a vanilla scent, the rats wait at the far left corner of the cage regardless of whether a food pellet is present. However, they do not wait in the far left corner when exposed to the lemon scent. What is the unconditioned stimulus in the experiment?
a. food pellet
b. vanilla scent
c. lemon scent
d. left corner of cage
Answer:
a. food pellet
Explanation:
In classical conditioning, an unconditioned stimulus is the stimulus that naturally elicits an unconditioned response. The unconditioned stimulus is usually paired with a neutral stimulus, and after pairing with a neutral stimulus, the neutral stimulus becomes a conditioned stimulus that elicits a conditioned response alone.
In the experiment described above in the question, the unconditioned stimulus is the food pellet, which naturally elicits the response of the rat to wait at the far left corner of the cage. The neutral stimulus which is paired with the food pellet is the vanilla scent, which now becomes the conditioned response, when paired alone.
5. What are HeLa cells? Why are HeLa cells appropriate for this experiment? Include references to information sources used to research HeLa cells.
6. Research the function of the protein called p53. What does this function do? Explain how it can affect cell cycle control. Include references to information sources used.
7. What is the Philadelphia chromosome? How is this chromosome related to cancer? Identify how this chromosome appears physically different in a karyotype than it appears in a normal karyotype. Include references to information sources used.
Explanation:
5.HeLa cells (also known as "HeLa cells" or simply "Hela") are a particular type of cell culture cell, used in scientific research. It is the oldest and most frequently used human cell lineage.The HeLa cells turned out to be perfect for the polio vaccine, and that experiment and the vaccine saved millions of people.
To develop it it was necessary for the virus to grow in the laboratory and for that human cells were required.
6. This protein is found in the nucleus of cells and plays an important role in the multiplication and destruction of cells. ... The p53 gene is a type of tumor suppressor gene.
Cell cycle arrest:
P53-mediated cell cycle arrest at the G1 / S checkpoint, when DNA damage is recognized, to prevent replication. It can be considered the main response when DNA damage occurs. The cell cycle arrest in the G1 / S transition is due to p53-dependent transcription of the CDKs inhibitor or also (CDC), cyclin-dependent kinase] called CDKN1A / p21. p21 inhibits CDK-cyclin complexes and prevents phosphorylation of pRb, so that transcription factor E2F remains inactive, and cell progression to the S phase (DNA synthesis) is prevented. This "pause" in the progression of the cell cycle gives time to repair DNA damage.
7.The Philadelphia syndrome or chromosome is an abnormality found on chromosome 22 of the body, and was discovered in 1960 by Philadelphia scientists Peter Nowell and David Hungerford; Both scientists worked in two different laboratories, but both were in the city of Philadelphia, and that is why this syndrome is named after the city in which they both discovered it.
This anomaly is linked to cancer because when presenting this anomaly of chromosomes 9 and 22, there seems to be a relationship with chronic myeloid leukemia. The truth is that, according to numerous studies carried out on patients with chronic myeloid leukemia, 90 percent of patients with this disease presented the anomaly of the Philadelphia syndrome.
The Philadelphia chromosome genetic defect consists of a phenomenon known as translocation, that is, a chromosomal break occurs in two specific regions of chromosome 9 and 22 (translocation 9-22), exchanging their positions. Specifically, the breakpoint occurs in the ABL gene (Abelson) on chromosome 9 (region q34) and in the BCR gene (Breakpoint Cluster Region, ) on chromosome 22 (region q11), giving rise to an altered chromosome 9 and a chromosome 22 also altered (Philadelphia Chromosome), but characterized by the fusion of these two genes (BCR-ABL), which encode a chimeric protein. The ABL gene takes its name from "Abelson," the name of a virus that causes leukemia, a precursor to a protein similar to that produced by this gene.
References
Zheng, Xiaomin; Güller, Saskia; Beissert, Tim; Puccetti, Elena; Ruthardt, Martin (November 7, 2006). "BCR and its mutants, the reciprocal t (9; 22) -associated ABL / BCR fusion proteins, differentially regulate the cytoskeleton and cell motility". BMC Cancer 6 (1): 262. ISSN 1471-2407. PMC PMC1637115 | pmc = incorrect (help). PMID 17090304. doi: 10.1186 / 1471-2407-6-262.
What percentage increase in population did Hidalgo and Willacy counties experience from 1997 to 2007? What problems can a rapidly growing population pose to a watershed?
Answer:
The answer is below
Explanation:
1. A) The percentage increase in population in Hildago between 1997 to 2007 is:
Given that Hildago population in 1997 = 511, 324
Hildago population in 2007 = 726,604
Hence, the percentage increase is 726,604 - 511,324 = 215280
Then 215280 ÷ 726604 = 0.2962 ≈ 29.62%
1. B) For Willacy
Willacy population in 1997 = 19,332
Hildago population in 2007 = 20,600
Hence, the percentage increase is 20,600 - 19,332 = 1268
Then 1268 ÷ 20600 = 0.0615 ≈ 6.15%
2. The problem a rapidly growing population posed to a watershed are:
A. impaired water bodies
B. percentage of surface waters impaired increases
C. source of pollution
D. number of waste water facilities draining into the water bodies.
If a brown hair allele is represented with a B, and blonde hair is represented with a b
Answer:
B. Brown Hair is dominant.
Explanation:
The dominant allele is represented with a capital letter, and a recessive allele is represented with a lower case letter.
Therefore, In this example brown hair is dominant. :)
Answer:
B; brown hair is dominant.
Explanation:
Alleles that are portrayed with uppercase letters are known to be dominant alleles. Brown hair is a darker color found commonly and is dominant over the blonde color which is overall lighter thus recessive.
So your answer would be B; Brown hair is dominant
Hope this helps!
Which situation is most likely to involve the action of a pheromone?
a. Albatrosses showing courtship behavior
b. A prairie dog emitting a loud yelp
c. The chirping of a cricket
d. Urine of a male mouse attracting a female
e. A male collared lizard showing his large mouth
Answer:
D. Urine of a male mouse attracting a female
Explanation:
Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to impact the behavior of the receiving individuals. There are alarm pheromones, food trail pheromones, sex pheromones, and many others that affect behavior or physiology.
Bees, wasps, ants, moths and other insects rely largely upon pheromones as a means of communication. Pheromones are chemical substances which may be secreted in urine, dung or produced by special glands.
Pheromones mediate many of the complex interplays within colonies of social insects such as bees, wasps, and ants.
Pheromones are chemical signals that have evolved for communication between members of the same species. A pheromone signal elicits a specific reaction in the receiver, for example, a stereotyped behavior (releaser effect) or a developmental process (primer effect). Some pheromones can have both effects. All sorts of molecules, large and small, have been found acting as pheromones, depending on whether the message is sent out on wind or water currents or placed directly on the nose or antenna of the recipient.
Most pheromones are detected by the sense of smell. However, not all smells are pheromones. Mammals, including humans, also give off a cloud of molecules that represent our unique individual "smell" or chemical profile. These differences between individuals make it possible for dogs to distinguish people by smell. People are quite good at it, too—parents can distinguish their baby from others by smell alone. Ants similarly can distinguish between members of their own colony and those from other colonies. In both mammals and insects, learning is necessary to develop this ability. The sources of the molecules that make up an animal’s "individual smell" include its own secretions and also may reflect its environment, food, bacteria, immune system, and molecules picked up from other individuals in its social group
A portal system Multiple Choice includes a functional end artery that makes an arterial anastomosis. is one in which circulation to a large organ involves only one artery and one main (portal) vein. is one in which multiple arteries converge on one organ or body region. is a simple circulatory system with an areriovenous anastomosis. is one in which blood flows through two capillary beds before being sent back to the heart.
Answer:
is one in which blood flows through two capillary beds before being sent back to the heart.
Explanation:
A portal system can be defined as a system of blood vessels having a capillary network at each end, meaning that the blood vessel starts and ends in capillaries, before finding its way back to the heart. The blood draining through the capillary bed flows via the larger vessel to supply the blood to the another structure's capillary bed.
A botanist discovers a new species of plant in a tropical rain forest. Investigation of its anatomy and life cycle shows the following characteristics : xylem, sporophylls with sori like structure, separate gametophyte and sporophyte generations with the sporophyte dominant, and no seeds. This plant is probably most closely related to ________. ferns gymnosperms mosses flowering plants
Answer:
fernsExplanation:
Such types of vascular plants that do not produce seed as well as flowers are called pteridophytes such as Ferns, lycophytes, and some other. Generally these plants reproduce by spores formation. They have certain characteristics such as have separate sporophyte and gametophyte generation. In the case of the Fern, the dominant phase is the sporophytic phase. Ferns have complex leaves that are known as megaphyllus. Mostly they are present in the tropical rain forest due to certain specific characteristics. How many sex chromosomes does a human diploid cell contain?
Answer:
. A human diploid cell has 46 chromosomes in 23 pairs.Imagine meiosis in a diploid organism that only has a single chromosome. Like most diploid organisms, it received one copy of this chromosome from each of its parents and the two homologs are genetically distinct.
If only a single homologous recombination event occurs during meiosis, which of the following choices below correctly describes the four gametes formed?
A) All four of the gametes will have chromosomes identical to the chromosomes found in the original diploid cell.
B) Three of the gametes will have chromosomes identical to the chromosomes found in the original diploid cell, while one of the gametes will have chromosomes that are different.
C) None of the gametes will contain chromosomes identical to the chromosomes found in the original diploid cell.
D) Two of the gametes will have chromosomes identical to the chromosomes found in the original diploid cell, while two of the gametes will have chromosomes that are different.
Answer:
two of the gametes will Java chromosomes identical to the chromosomes found in the original diploid cell,while two of the gametes will have chromosomes that are different
A random-digit dialed survey conducted in the city of long beach, california reported that a greater proportion of nonsmokers endorsed a ban on smoking in alcohol-serving establishments than did smokers. What type of study design was this?
Answer:
The correct answer is case-control study.
Explanation:
In a case-control study, two groups of the population are used, in which one group is kept as control, and the other is known as the experimental group that encounters with a specific disease or an outcome. With the help of this study, one can expose the groups to various or single outcomes.
In the given case, a study is done in which an advertisement on a ban on smoking is encouraged by the non-smokers at the alcohol sale points but not by smokers, in the process a random digit dialing method was used. This random digit dialing method is an illustration of a case-control study, in which the survey of the individuals is done regarding the ban on smoking.
A study conducted via a random-digit dialed survey in Long Beach, California, assessing attitudes toward smoking bans among smokers and nonsmokers, exemplifies a cross-sectional study design.
The study described in the city of Long Beach, California, where a random-digit dialed survey reported that a greater proportion of nonsmokers endorsed a ban on smoking in alcohol-serving establishments compared to smokers, is an example of a cross-sectional study.
This type of study design involves analyzing data collected from a population, or a representative subset, at a specific point in time. In this case, the survey aimed to assess attitudes toward smoking bans among different groups within the population at a single point in time, without following up with participants over time. Cross-sectional studies are particularly useful for assessing the prevalence of behaviors or opinions in a population.
What is the difference between evolution and coevolution?
Answer:
Evolution is the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth. Coevolution is the influence of closely associated species on each other in their evolution.
Explanation:
Final answer:
Evolution is the gradual change within a species over time, while coevolution is the mutual evolutionary influence between two interdependent species, such as in predator-prey relationships or mutualistic interactions like flowering plants and their pollinators.
Explanation:
The difference between evolution and coevolution is that evolution refers to the changes that occur within a species over time due to environmental changes, natural selection, and genetic drift, among other factors. In contrast, coevolution involves two or more species influencing each other's evolutionary path, typically because they are interdependent, such as in symbiotic relationships or predator-prey dynamics. For instance, the coevolution between flowering plants and their pollinators, where the plant evolves specific traits to attract certain pollinators, and the pollinators evolve adaptations that allow them to more effectively access the flowers' nectar or pollen. A notable example is the close relationship between some insects and flowering plants; insects have developed specialized body structures to reach nectar, while flowering plants have evolved unique shapes and colors to attract these insects.
Baby Phelps was born without a thymus gland. Immediate plans were made for a transplant to be performed. In the meantime, baby Phelps was placed in strict isolation. Why was this done?
Explanation:
Thymus is a primary lymphoid organ where T cells mature, T cells mature in the cortex and migrate to medullaT cells do not produce antibodies, when antigen presenting cells bring antigens in the secondary lymphoid organ, T cells helps in their eliminationThere are two types of T cells: T helper cells and T-cytotoxic cellsT helper cells carries membrane protein on surface and provides defense against both extracellular and intracellular pathogensT cytotoxic cells is the carrier of surface protein and provides defense against intracellular pathogensSo, baby Phelps was placed in strict isolation because it plays a vital role in protecting the baby's immune system
A 6-month-old vaccinated infant arrives in the ED with a 12-hour history of poor feeding, emesis, and irritability. On exam, she is ill-appearing with T 39.2 C, P 160 bpm, R 40 bpm, BP 80/50 mmHg. CBC shows WBC 11.2, Hgb 13.5, Plt 250. Urinalysis shows > 100 WBC per hpf, positive leukocyte esterase, and positive nitrites. She has no history of prior urinary tract infection. Chest x-ray is negative. Urine and blood cultures are pending. After bringing her fever down, she is still uninterested in drinking, but her exam improved, and you are confident she does not have meningitis, so an LP is not performed.
Which of the following is the best next step in management?
A. Oral ampicillin
B. Oral ampicillin + gentamicin
C. Intravenous ciprofloxacin
D. Intravenous ceftriaxone
E. Intravenous piperacillin + tazobactam
Answer:
D. Intravenous ceftriaxone
Explanation:
Intravenous ceftriaxone
This patient's presentation is suggestive of a UTI. Given the ill appearance, vital signs, and white count, Upper tract disease (pyelonephritis) should be strongly considered. A parenteral (IV/IM) third-generation cephalosporin is the best choice of those listed for pyelonephritis, given its excellent gram negative coverage (except for Pseudomonas).
Answer: INTRAVENOUS CEFTRIAXONE
Explanation: To understand the question very well,let's critically look at the age of the infant and the presenting signs and symptoms.
The infant has a history of poor feeding,emesis(vomitting) and also there is history of irritability.there is also fever.when you look at all these,it is closely related to the signs and symptoms presented by infants with UTI ( urinary tract infection) but when you consider the vital signs of the infant (Temperature: 39.2°c, Respiratory: 40bpm,and Blood pressure: 80/50mmHg), the white blood cell count and the I'll looking appearance of the infant,
Upper tract disease that is (pyelonephritis) should be considered more because the signs and symptoms indicative of pyelonephritis are more strong than that of UTI.
Looking at the age of the infant and the severity of the presenting signs and symptoms, parenteral drug administration(intravenous/intramuscular) will act faster and will be easily absorbed and as well as easily accepted by the infant than enteral adminstration.
Looking at the options listed in the question,ceftriaxone is a third generation cephalosporin (a class of antibiotics used to treat varieties of bacteria infections) and it is so far the best drug in the treatment of pyelonephritis and also the best from the options given in the question,it's effectiveness is seen in the fact that it's gram negative coverage is excellent except in the case of pseudomonads where there is no encouraging gram negative coverage.
In a line of human cells grown in culture, a geneticist isolates a temperature-sensitive mutation at a locus that encodes an acetyltransferase enzyme; at temperatures above 38°C, the mutant cells produce a nonfunctional form of the enzyme. What would be the most likely effect of this mutation if the cells were grown at 40°C?
Answer:
A general decrease in transcriptional activation
Explanation:
When acetyl groups are added to histone proteins by acetyltransferase enzymes, the 30-nm chromatin fiber will not be formed because the proteins are prevented from doing so. This further destabilizes the chromatin structure and allows the occurrence of transcription. However, raising the cells to 40°C does not allow the acetyltransferase enzyme to function and hence the acetyl group will be hindered from being added to the histone protein which is the main target of the enzymes. Thus, transcription activation will be blocked because the chromatin and nucleosomes would remain stabilized.
Answer:
A general decrease in transcriptional activation
A desert area has many species of cactus and brush as well as birds, snakes, lizards, and rodents. This desert is an example of a _____________________
Answer:
climax community
Explanation:
PLEASE HELP ME ASAP!!!!
Which should a scientist conclude about data that are inconsistent with the current, new scientific understanding of amphibian reproduction?
a) A new idea or theory should be devised to fit new data.
b) Inconsistencies in the data warrant further investigation.
c) The data are flawed and should be discarded or ignored.
d) The data reflect the flaws in the current scientific ideas.
Answer:
Inconsistencies in the data warrant further investigation
Explanation:
When you find something new and exciting in your field of study you should always investigate further to see if certain circumstances in the situation led to your findings. If you discover that all of the female amphibians in a pond lay a few days later in the spring and normally this wouldn't happen you should always see if another pond of amphibians lay around the normal time. The water temperature could affect the laying time, the predators that are around could affect laying time, the animals comfort and even that could just be when it happens for them. But double and triple checking is always ideal, so that you are able to publish and share accurate information to help other scientists see and experience what is actually happening.