Answer:
The main difference between these two classes is that: Pteridophytes are vascular plants but they do not produce flowers and seeds which mean their source of reproduction is unknown or hidden. Examples are ferns, horsetails and lycophytes. On the contrary, Spermatophytes as the name indicates, are seed bearing plants.
Explanation:
Answer:
THE DIFFERENCE is that spermatophyte is (botany) any plant that bears seeds rather than spores while pteridophyte is any plant of the division pteridophyta, of simple vascular plants that reproduce via spores rather than seeds and that alternate generations of diploid (sporophyte) and haploid (gametophyte or prothallus) forms
Explanation:
Industrial melanism refers to the dark pigmentation that evolved in some insects giving them protective coloration on vegetation darkened by soot in heavily industrialized areas prior to air pollution regulation. Assume that in one heavily polluted area near Birmingham, England in 1956, 79% of the moths of the species Biston betularia were black due to the presence of a dominant gene for melanism. Estimate the frequency of the dominant allele in this population, and the proportion of black moths that are heterozygous.
Answer:
The frequency of the dominant allele, p = 0.542The proportion of black moths that are heterozygous 2pq = 0.496Explanation:
According to Hardy-Weinberg, the allelic frequencies in a locus are represented as p and q, referring to the allelic dominant or recessive forms. The genotypic frequencies after one generation are p² (Homozygous dominant), 2pq (Heterozygous), q² (Homozygous recessive). Populations in H-W equilibrium will get the same allelic frequencies generation after generation. The sum of these allelic frequencies equals 1, this is p + q = 1.
In the same way, the sum of genotypic frequencies equals 1, this is
p² + 2pq + q² = 1
Being
p the dominant allelic frequency,q the recessive allelic frequency,p² the homozygous dominant genotypic frequencyq² the homozygous recessive genotypic frequency2pq the heterozygous genotypic frequencyIn the exposed example, 79% of the moths of the species Biston betularia were black due to the presence of a dominant gene for melanism.
If the genotypic frequency of back moths is 0.79, then, by performing the following equation we can get the not-black moths genotypic frequency:
p² + 2pq + q² = 1
where p² is the homozygous dominant genotypic frequency, q² the homozygous recessive genotypic frequency, and 2pq is the heterozygous genotypic frequency.
As 0.79 is the phenotypic frequency of black moths, then this frequency equals p²+2pq.
Clearing the equation:
p² + 2pq + q² = 1
0.79 + q² = 1
q² = 1 - 0.79
q² = 0.21
The genotypic frequency of non-black moths is 0.21. So, from here we can calculate the allelic frequency:
q² = 0.21
q= v 0.21
q = 0.458
If 0.46 is the allelic frequency of non-black moths, then by clearing the equation p + q = 1, we can get the p allelic frequency:
p + q = 1
p + 0.458 = 1
p = 1 - 0.458
p = 0.542
The genotypic frequency p² = (0.542)² = 0.294The heterozygote genotypic frequency2 x p x q = 2 x 0.542 x 0.458 = 0.496
Finally, we can check this answer by clearing the following equation:
p² + 2pq + q² = 1
0.294 + 0.496 + 0.21 = 1
Difference between Squamous epithelium and Stratified epithelium. (Pls answer quick)
Answer:
squamous epithelium consists of a single layer of flat cells. It is found in lungs,heart and blood vessels.It allows the movement of materials across it.
stratified epithelium has many layer of flat cells.It is present in lining of oesophagus and mouth and also over the skin
Which type of mutation is likely to have the least affect on an organism
Answer:
Point Mutations
A point mutation—the change of a single nitrogen base in a DNA sequence—is usually the least harmful type of DNA mutation
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Which of the following is a type of action, assistance, or information that a genetic counselor can provide? Check all that apply.
Calculate the risk of a child inheriting a genetic disorder.
Look for patterns of inheritance in a client’s family history.
Prescribe a medication to help with a client’s anxiety.
Explain causes and inheritance patterns of a genetic disorder.
Recommend the best of several long-term options for a client.
Explain what genetic tests are available and what information they would provide.
Interview a client to obtain details of the family’s medical and genetic history.
Order a test to be done without the client’s approval if it would provide useful information.
Answer: Calculate the risk of a child inheriting a genetic disorder.
Look for patterns of inheritance in a client’s family history.
Explain causes and inheritance patterns of a genetic disorder.
Recommend the best of several long-term options for a client.
Explain what genetic tests are available and what information they would provide.
Interview a client to obtain details of the family’s medical and genetic history.
Explanation:
The genetic counseling will involve the following steps:
1. The counselors check the family medical history and medical records of parents to estimate the chances of inheritance of genetic disorder or disease in a developing fetus.
2. The counselors order genetic testing.
3. The counselors evaluate the results of the tests.
4. They counsel parents based on the results and recommend them the long term options to prevent the effect of disease.
Answer:
1 2 4 6 7
Explanation:
Through logic and the prosess of elimenation I found the answers.
Consider a simplified metabolic model to describe nitrogen metabolism in the body. Nitrogen is ingested in the food (F), a fraction of which is actually absorbed (A), the remainder being lost in the feces (W). The absorbed nitrogen is taken up by the muscle to make protein. At small fraction of the stored muscle protein undergoes degradation and the liberated nitrogen (L) is released from the muscle. Of the liberated nitrogen, a fraction is recycled back to the muscle (R), while the rest is lost to excretion (E) in the urine
The given question is incomplete, the complete question is:
Consider a simplified metabolic model to describe nitrogen metabolism in the body. Nitrogen is ingested in the food (F), a fraction of which is actually absorbed (A), the remainder being lost in the feces (W). The absorbed nitrogen is taken up by the muscle to make protein. At small fraction of the stored muscle protein undergoes degradation and the liberated nitrogen (L) is released from the muscle. Of the liberated nitrogen, a fraction is recycled back to the muscle (R), while the rest is lost to excretion (E) in the urine. If the nitrogen ingested in food is 100 g/day, but only 80% of the food is actually absorbed, while the rest goes to waste, what is the amount of nitrogen lost by excretion? Assume steady-state. Of the nitrogen liberated from muscle, 90% is excreted, while the rest is recycled, what fraction of the nitrogen entering the muscle is from the absorbed food? (In other words, what is the ratio A/(A+R)). Again, assume steady-state
Answer:
The amount of nitrogen lost in the process is 20 grams in a day and the fraction of nitrogen entering the muscle is 0.909.
Explanation:
Based on the given question, the amount of nitrogen absorbed is 80 percent of 100 grams, that is,
100*(80/100) = 80 grams in a day.
The concentration of nitrogen lost in the process is,
Nitrogen ingested-nitrogen absorbed = 100-80 = 20 grams in a day.
Let us assume that all the ingested nitrogen is liberated from the muscle. Therefore, 80 grams of nitrogen is liberated. If 90 percent of the nitrogen liberated from the muscle get excreted, then the value of excreted nitrogen will be,
90% of 80 grams = 90/100*80 = 72 grams
Now the nitrogen recycled will be,
Liberated nitrogen - excreted nitrogen = 80-72 = 8 grams
From the absorbed food, the fraction of the nitrogen entering the muscle will be,
80/(80+8) = 80/88 = 0.909.
Look at the ocean system described below.
plankton
herring
octopus
shark
What will most likely happen to this ecosystem if the herring are killed by a
virus?
A. The shark population will increase.
B. The plankton will die off over time.
C. The octopus population will increase.
D. The octopus and shark populations will decline.
Answer:
I think the ans is D (The octopus and shark populations will decline.)
Most likely happen to this ecosystem if the herring are killed by a
virus D. The octopus and shark populations will decline.
What is a ecosystem?An ecosystem is a geographic area where plants, animals, and other organisms, as well as weather and landscapes, work together to form a bubble of life.
What is importance of ecosystem?As a society, we depend on healthy ecosystems to do many things; to purify the air so we can breathe properly, sequester carbon for climate regulation, cycle nutrients so we have access to clean drinking water without costly infrastructure, and pollinate our crops so we don't go hungry.
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The feces of birds and mammals can also be used to assess ecosystem health. Research this methodology and provide two examples of animals used for these studies and the types of materials that are identified in their feces
Answer:
Birds and leopard
Explanation:
It has been researched and discovered that the feces of birds and animals can be used to determine the state of health of an ecosystem.
For example, it has been discovered that hormones and other substances are excreted through urine and feces. And researchers have discovered from the feces of leopards, that a leopard that has cave or trees where it can hide from hunters are not likely to be stressed out like the one that does not have.
Identify the structure represented in the picture . Then, identify the parts labeled A—D.
Given structure is that of a virus, which includes the viral capsid, nucleic acid, etc.
A= spike
B= Envelop
C= Nucleic acid
D= Capsid
What are Viruses?Small infectious agents known as viruses can multiply only in the living cells of other animals. They are composed of genetic material, which can be DNA or RNA, encased in a protein shell called a capsid. Some viruses also have a lipid-based outer coat.
Because they cannot perform metabolic functions on their own and require a host cell to reproduce, viruses are not considered living organisms. They spread infection to various living things including bacteria, plants, animals and people.
A virus replicates its genetic material and forms new viral particles when it infects a host cell using the host cell's machinery. This can lead to the death of the host cell and result in the spread of the virus to other cells of the host.
Therefore, given structure is that of a virus, which includes the viral capsid, nucleic acid, etc.
A= spike
B= Envelop
C= Nucleic acid
D= Capsid
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Examples of stimulants include
a. Nicotine
b. Ecstasy
c. Dextromethorphan
d. A and B
Answer:
The answer to this question is d(A and B)
Explanation:
Hope this helps
Answer:
d but also c !
Explanation:
A and B are correct but also dextromethorphan has lower doses of stimulants
What's the difference between Columnar Epithelium and Glandular Epithelium. (Pls answer fast T_T)
Answer:
glandular epithelium are specialized for secretion. lining epithelium simply lines organs like the stomach. ... Endocrine glands release substances within the body and exocrine glands release substances outside the body.
Simple columnar epithelia are tissues made of a single layer of long epithelial cells that are often seen in regions where absorption and secretion are important features. The cells of this epithelium are arranged in a neat row with the nuclei at the same level, near the basal end ...
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Introduction to Biology: Mastery Test
5
A student notices that when bananas are kept near other fruits, the other fruits ripen faster. She wonders what causes
more quickly and thinks that bananas must have an influence on the ripening process. She decides to perform an expe
bananas and apples and places an apple by itself at location A and an apple next to a banana at location B. She then w.
records the how ripe each apple is.
What would be the next step in this experiment?
O A
ask questions and construct a hypothesis
B.
make observations and draw a conclusion
O c.
construct a hypothesis and record data
D.
analyze the results and make a conclusion
Answer:
Explanation:
The next step in this experiment is constructing a hypothesis and recording data. The correct option is (C).
Making observations and keeping track of data would be the experiment's next phase. The learner would observe and record the ripening of both apples at locations A and B in this stage. They would have to keep track of the maturity of the apples throughout time by routinely observing and recording the changes. This could entail examining the apples visually for color, texture, and overall maturity and recording any variations between the apples at locations A (by themselves) and B (next to a banana).
The student can analyze the results and develop conclusions regarding the impact of bananas on the maturity of other fruits by gathering information on the ripening of the apples in both locations. The information can be used to prove or disprove the initial theory and assist determine whether bananas actually influence the maturity of surrounding fruits.
Hence, the correct option is (C). Construct a hypothesis and record data.
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phosphate from atp is removed to make adp and a free phosphate molecule
Answer:
ATP is a nucleotide consisting of an adenine base attached to a ribose sugar, which is attached to three phosphate groups. ... When one phosphate group is removed by breaking a phosphoanhydride bond in a process called hydrolysis, energy is released, and ATP is converted to adenosine diphosphate (ADP).
Select the choices that best complete the following sentence: An inherited feature of an organism is a ______ whereas a variant of that feature is called a ______.
A.
homozygote; heterozygote
B.
chromosome; factor
C.
hybrid; gamete
D.
character; trait
E.
allele; gene
Answer:
A
Explanation:
Homozygous means that both copies of a gene or locus match while heterozygous means that the copies do not match. Two dominant alleles (AA) or two recessive alleles (aa) are homozygous. One dominant allele and one recessive allele (Aa) is heterozygous.
The same sentences are written with a substitution, deletion, or insertion, much as a gene may have a substitution, deletion, or insertion mutation. Identify which sentence represents a substitution, which represents a deletion, and which represents an insertion.
Answer:
The question is incomplete, the complete question has been added as an attachment.
THE DGR AN represents deletion mutation
THE RED ANA TRA N represents insertion mutation
THE FOX WTS RED represents substitution mutation
Explanation:
Mutation is a change in the nucleotide sequence of a gene. It can be of different types depending on how it occurs. A deletion mutation is that which involves the removal of one or more nucleotide base from the sequence.
An insertion mutation is the addition of one or more nucleotide bases to the sequence.
A substitution mutation is the replacement of one or more nucleotide base in a sequence.
The original sentences were:
1. THE RED ANT RAN
2. THE FOX WAS RED
3. THE DOG RAN
The three sentences that mutated/changed are:
1. THE DGR AN- in this sentence, letter O which represents one base is missing due to removal, making the original sentence (THE DOG RAN) alterated. Hence, this represents an example of deletion mutation.
2. THE RED ANA TRA N - in this case, Letter A has been added in between N and T. This makes the original sentence (THE RED ANT RAN) altered. Since addition of letter (base) occurred, this represents an example of insertion mutation.
3. THE FOX WTS RED - In this case, letter A in "WAS" was replaced by T, making the original sentence (THE FOX WAS RED) altered. Since a replacement of letter (base) is the case here, it represents an example of substitution mutation.
The results of gel electrophoresis are shown below. What can you determine
about the DNA from looking at the results of this test?
electrode
A. Strand 1 is the smallest.
B. Strand 2 is larger than strand 3
C. Strand 3 is larger than strand 4.
D. Strand 4 is the smallest
Answer:
A
Explanation:
Gel electrophoresis is an amazing technique that allows for DNA separation based on size (as in, length). Using electricity (and keeping in mind that DNA has a negative charge because of the phosphate groups), the shortest pieces will migrate the farthest.
So we can tell that the pieces are in ascending order of size. 4>3>2>1, in length.
A. Strand 1 is the smallest.
Answer:Given results of gel electrophoresis shows that strand 1 is smallest. The pieces are arranged in ascending order of size 4>3>2>1 . Thus,option A is correct.
Explanation:
What is Gel electrophoresis?
Gel electrophoresis is a laboratory technique used to separate mixture of DNA ,RNA or protein according to their molecular size.
The gel used in this technique is composed of polyacrylamide or agarose.
The main application of gel electrophoresis has been in the seperation of molecules and in restriction mapping.
The main advantage of gel electrophoresis is its capability to
simultaneously separate various samples in one round.
Therefore, strand 1 is the smallest according to the result of gel electrophoresis shown in figure. Thus, option A is correct.
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You are studying a bacterium that utilizes a sugar called athelose. This sugar can be used as an energy source when necessary.Metabolism of athelose is controlled by the ath operon. The genes of the ath operon code for the enzymes necessary to use athelose as an energy source.You have found the following:The genes of the ath operon are expressed only when the concentration of athelose in the bacterium is high.When glucose is absent, the bacterium needs to metabolize athelose as an energy source as much as possible.The same catabolite activator protein (CAP) involved with the lac operon interacts with the ath operon.Based on this information, how is the ath operon most likely controlled?Drag the labels onto the diagram to identify the small molecules and the states of the regulatory proteins. Not all labels will be used.POSITIVE CONTROLa) Inactive Activator (not glowing, w/o yellow square)b) cAMPc) Active Activator (glowing, w/ yellow square)NEGATIVE CONTROLd) Active Repressor (glowing, w/o yellow square)e) athelosef) Inactive repressor (not glowing, w/ yellow square)
Answer:
POSITIVE CONTROL
c) Active Activator
d) Active Repressor
NEGATIVE CONTROL
f) Inactive repressor
a) Inactive Activator
b) cAMP
Explanation:
The positive controls are those groups in the experiment whose treatments are expected to confirm previously known results, thereby enabling the comparison of these results with the target group. In this case, both active activators and repressors are able to give results that can be compared with the test group
The negative controls are those experimental groups where no response is expected. In this case, both inactive activators and repressors, and cAMP (which is a secondary messenger in diverse biological processes but is not involved in this pathway), are not expected to produce any measurable response.
What explains the presence in living humans of DNA sections which are identical to DNA
found in Neanderthals who lived 40 000 years ago?
Answer:
It can be explained by hybridization among human and neanderthal ancestral populations.
Explanation:
Next-generation sequencing (NGS) technologies coupled with bioinformatics tools have enabled to confirm admixture between Neanderthals and humans. The technique to identify admixture events consists in discovering nucleotide regions from neanderthal genomes that could be inserted in human genomes, thereby the observed sequence homology must be statistically significant (e-value). This emergent research field is known as paleogenomics.
In each of the scenarios, an individual heterozygous for the indicated gene or genes is crossed with an identical heterozygous individual. Predict the number of different phenotypes that would be observed among the progeny of such a cross.
Scenario 1 : R is completely dominant to r.
Scenario 2: R is codominant with r.
Scenario 3: R and S are completely dominant to rand s, respectively; R and S are linked by 15 m.u. and do not interact with each other.
Scenario 4: Genes R and S perform the same function; R and S are completely dominant to r and s, respectively; and R and S are unlinked.
Scenario 5: R and S are completely dominant to r and s, respectively; R and S are linked by 10 m.u. and show dominant epistasis.
Answer:
Explanation:
Scenario 2: R is codominant with r.
Scenario 3: R and S are completely dominant to rand s, respectively; R and S are linked by 15 m.u. and do not interact with each other.
Scenario 4: Genes R and S perform the same function; R and S are completely dominant to r and s, respectively; and R and S are unlinked.
Scenario 5: R and S are completely dominant to r and s, respectively; R and S are linked by 10 m.u. and show dominant epistasis.
The first line of defense involves which structure(s)?
O T-cells
O skin
O blood
O B-cells
Mark this andretum
Next
Submit
Answer:
skin.
Explanation:
the first line of defense uses physical parts such as skin.
This solid layer is found between the inner mantle (mesosphere) and the lithosphere.
O A. crust
B. asthenosphere
C. inner core
O D. outer core
Answer:
The layer below the rigid lithosphere is a zone of asphalt-like consistancy called the Asthenosphere . The asthenosphere is the part of the mantle that flows and moves the plates of the Earth.
Explanation:
8. The function of lipoproteins in blood serum is to:
a. aid in blood clotting
b. transport cholesterol
c. maintain pH
d. remove defective red blood cells
Which of the following removes waste from the body through perspiration? blood kidneys skin large intestine
Answer:
Kidneys, skin and large intestine. Organs of excretion include the skin, liver, large intestine, lungs, and kidneys. All of them excrete wastes, and together they make up the excretory system. The skin plays a role in excretion through the production of sweat by sweat glands.
Explanation:
Answer: SKIN
Explanation: Perspiration is the process of sweating so your skin does that
Species of bacteria can evolve more quickly than
species of mammals because bacteria have
Answer:
540MIL0IAER
P
Explanation:
F
VFVVEV
Answer:
Bacteria have smaller populations, grow faster, and also share more genes compared to mammals.
Explanation:
Because bacteria reproduce quicker and are also in smaller populations, they can evolve quicker because more genes are shared which can be helpful. This is due to natural selection, which will affect bacteria more than mammals because their small populations will make natural selection more significant to be harmed by mutations and allow them to evolve.
Why to use small beads for immobilizing enzymes
Answer:
Explanation:
Effects of bead size and bead amount on enzyme activity. Beads containing crude enzyme were prepared in the presence of sodium alginate (2% w/v) in CaCl 2 (5% w/v) solution. Each treatment was performed in triplicate.
Select all that apply. Which of the following are vertebrates? earthworms grasshopper lancelets octopus crab amphibians tunicates starfish
Answer: amphibians
Explanation:
earthworms, grasshopper, lancelets, octopus, crab, tunicates, starfish are all invertebrates.
lancelets(cephalochordata) and tunicates(urochordata) are chordates but do not have a backbone.
Hii!! The correct answer is amphibians. (:
Fat mobilization is the breakdown of fats in adipose tissue into metabolic products that enter the bloodstream place the steps of fat mobilization in order
Actual Answer:
1) body releases epinephrine
2) epinephrine binds to fat cells in adipose tissue
3) tricylglycerols are hydrolyzed to glycerol & fatty acids
4) metabolic products enter the bloodstream
Answer:
The complete steps are:
1. Body needs energy for activity
2. body releases epinephrine
3. epinephrine binds to fat cells in adipose tissue
4. triacylglycerols (triglycerides) are hydrolyzed to glycerol and fatty acids
5. Fatty acids transported to tissue
Explanation:
Mobilization of fat is a gluconeogenetic process (a process that sequesters energy from a compound other than carbohydrates), in which fat molecules in the adipose tissues are metabolized for energy production.
The process starts when the body is in an energy-deprived (hypoglycemic) state, leading to the release of glucagon by the pancreas and the release of epinephrine (adrenaline) from the adrenal medulla of the brain.
These hormones activate gluconeogenesis and glycogenolysis (breakdown of glycogen) in the liver, it also activates lipolysis in the muscle cells and liver, as well as inhibiting fatty acid synthesis. This is mediated through the binding of these hormones to specific receptors on the surface of fat cells, leading to the activation of lipases (enzymes catalyzing lipolysis). Lipases catalyze the hydrolysis of triglycerides (common fat in diets) to glycerol and three molecules of free fatty acids. These free fatty acids are released into the blood where they attach to serum albumin; a protein for transporting the hydrophobic fatty acids to the muscle cells where they are taken up and utilized to produce energy and C0₂.
How can you determine the optimum pH of an enzyme?
You can determine the optimum pH of an enzyme by graphing its pH activity and studying the results.
Enzymes each perform differently in distinct environments. Some require lower pH to function, while others achieve maximum performance at higher pH levels.
This relationship between the productivity of the enzyme and the pH can be studied and graphed. Once done, we can expect this graph to look like a parabola, increasing steadily until maxed, then gradually decreasing back to zero at the other extreme. The vertice of this parabola will give us the optimum pH for the enzyme.
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5. Find the LC.M of XX,X-1,X-X
Answer:
-1 I believe
Explanation:
The genetics of a-thalassemia are similar to narrow sense heritability in that there is a gradation of phenotype, with each allele seeming to contribute equally to the trait. However, there are also differences from narrow sense heritability. In particular, as you can see from your answers above, it is difficult to predict offspring phenotype based only on parental phenotype. What two aspects of HBA1 and HBA2 combine to offset what would otherwise appear to be narrow sense heritability of a-thalassemia?
Answer:
In strict mode, the narrow-sense heritability is the proportion of the additive genetic variance that contributes to the total of the phenotypic variance. This value can be associated with the inheritance of the a-thalassemia .
Explanation:
A-thalassemia is a genetic disorder caused by mutations affecting four different genes that encode alpha-globin, thus affecting the hemoglobin production process and, consequently, oxygen transport. The mode of inheritance of the a-thalassemia may be associated with narrow sense heritability since the phenotype is manifested by gradation, i.e., each allele might contribute in similar mode to this genetic condition.
Which happens during the second trimester?
A. Blood pumps through the heart.
B. The stomach produces digestive fluids.
C. The lips begin to develop.
D. Teeth begin to form.
Answer:
The lips begin to form. I know that during the second trimester ears and eyes begin to develop, so I assume that lips would also begin to develop too.
In pregnancy, during the second-trimester blood pumps through the heart. The correct option is A.
What is trimester?A pregnancy is divided according to the weeks namely trimesters, these are first trimester, second trimester, and third trimester.
A trimester usually occurs between 12 and 14 weeks and a full-term pregnancy occurs at around 40 weeks.
In pregnancy, during the second-trimester blood pumps through the heart.
Thus, the correct option is A.
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