Answer:
The correct answer for this is C, because the Fadh2 is only involved at the redox reactions.
Explanation:
ATP is just a product from glycolysis. Remember that when you break the glucose, energy is been free as an ATP molecule. NADH2 is a substratum, you need it, to get NAD at the fermentation process in the cytoplasmic matrix. Pyruvate and phosphoenolpyruvate are also products at the glycolysis.
Pea seed color exists as green or yellow. We might say that "yellow" is an example of a (an)_ for seed color
a. genotype
b. allele
c. karyotype
d. homozygote
e. heterozygote
Answer:
b. allele
Explanation:
An allele is a variant form of a gene. In this problem, there is one gene (that determines seed color) with two possible alleles (green and yellow).
The other options are wrong because:
The genotype is the combination of alleles an individual has.
The karyotype is an individual's collection of chromosomes, paired and ordered.
A homozygote individual has the same alleles for a particular gene.
A heterozygote individual has different alleles for a particular gene.
Describe four reasons why eukaryotic reproduction is more complex than prokaryotic reproduction.
Answer:
Explanation:
1. In prokaryotes , the reproduction takes place by asexual means such as binary fission whereas in eukaryotes the reproduction takes place by sexual means.
2. In eukaryotes mates are required which allows the fusion of males and female gametes, whereas in prokaryotes no mates are required offspring produce from single parent.
3. In prokaryotes many offspring produce from a single parent whereas in eukaryotes only few offspring are produced.
4. Growth of offspring development is complex in eukaryotes whereas the offspring development is simple in prokaryotes.
Final answer:
Eukaryotic reproduction is more complex than prokaryotic due to the presence of membrane-bound organelles, a larger and more complex genome with multiple linear chromosomes, a detailed process of cell division called mitosis, and a slower replication rate requiring tight regulation.
Explanation:
Eukaryotic reproduction is more complex than prokaryotic reproduction for several key reasons.
Eukaryotic cells have numerous internal membrane-bound organelles, such as mitochondria and chloroplasts, that need to be replicated and properly distributed during cell division.The eukaryotic genome is far more intricate and larger, with eukaryotes housing multiple linear chromosomes and up to 100,000 origins of replication. This creates a more complex replication process compared to prokaryotes, which have a single circular chromosome.Eukaryotes undergo a detailed and orderly process of cell division known as mitosis, with distinct phases such as prophase, metaphase, anaphase, and telophase, each with specific and vital roles in the successful division of the cell.The rate of replication in eukaryotes is slower than in prokaryotes, about 100 nucleotides per second, creating a longer, more intricate process requiring tight regulation and coordination.Starch is broken down into ____________ by the enzyme ___________
Starch is broken down into maltose by the enzyme amylase. Maltose is then further hydrolyzed into glucose by the enzyme maltase, primarily in the small intestine.
Starch is broken down into maltose by the enzyme amylase. Initially, starch is hydrolyzed by salivary amylase in the mouth and later by pancreatic amylase in the small intestine, producing shorter polysaccharides, dextrins, and disaccharides like maltose. These smaller sugars are easier for the body to absorb. Following this, the enzyme maltase, which is produced by the cells in the small intestine, further breaks down maltose into individual glucose molecules, which are used by the body for energy.
In October of 2002, General Mills Inc. recalled over 4,000 cans of refried beans suspected to be contaminated with Clostridium botulinum. Which of the following statements regarding adult botulism is correct?
a. the anaerobic environment of the sealed can provides a suitable environment for the spores to germinate.
b. the spores produce a potent neurotoxin
c. symptoms of the disease are stiff, contracted muscles, such as "lockjaw", and eventual paralysis of the respiratory muscles, which results in death
d. reheating the beans to kill the bacteria will prevent the disease.
e. all of the above statements are correct
Answer:
A and B
Explanation:
A and B are correct answers.
C is incorrect because Botulism does not produce stiff muscle, in fact it produces flaccid paralysis. Stiff muscles and lockjaw is produced by C. Tetani.
D is somewhat incorrect because, although you can kill the toxins via heat, you would need to heat your food to over 100°C for around 10 minutes, which no one does. Thus, reheating beans would not protect you from the bacteria and/or its toxins.
Alkaline pancreatic juices work in ___________
a. chemical digestion
b. neutralize pepsin
c. neutralize acid chyme
d. remove HCL
Answer:
The correct answer will be Option-C.
Explanation:
The pancreas is an organ which plays an important role in the digestion of the food. Pancreatic juice is secreted by the pancreas which contains digestive enzymes as well as the sodium bicarbonate (base).
The sodium bicarbonate is required for the digestion of the food as after the acidic digestion of the food in the stomach, the food chyme enters small intestine. The inner lumpen is not structured to handle the acidic chyme so sodium bicarbonate neutralizes the acid chyme that entered the lumen of the small intestine.
Thus, Option-C is the correct answer.
Males have hemophilia when they are hemizy-gous for a nonfunctional recessive mutant allele of the X-Iinked gene for clotting factor Vlll. Factor Vlll is normally secreted into the blood serum by cells in the bone marrow that produce it. a. Do you think that females heterozygous for the hemophilia disease allele could have hemophilia in some parts of their bodies and not others? b. If such a female "carrier" of hemophilia suffered a cut, would her blood coagulate (form clots) faster, slower, or in about the same time as that of an individual homozygous for a normal allele of the factor Vlll gene? Would the rate of clotting vary significantly among heterozygous females?
Answer:
a. No, it is not possible.
A heterozygous female carries one copy of functional gene which is enough for the production of clotting factor. Hemophilia does not show continuous variation or polygenic inheritance and thus, its level does not depend on the number of normal alleles.
It that was the case, then all males would show hemophilia in some parts of the body as they only carry one X chromosome and thus, only one functional gene.
Thus, heterozygotes are only the carriers of the disease, they do not show any symptom of the disease.
b. In perspective of homozygosity or heterozygosity, the rate of blood clotting should be the same as both of them have functional gene. As mentioned above, it does not show continuous variation so, it will not show any increased or decreased rate of clotting in homozygotes or heterozygotes.
However, in reality, the rate of clotting depends on the concentration of clotting factor present in blood plasma. This percentage depends on the physiology of a person but not on the number of alleles present. For example, proteins or enzymes required for gene expression, et cetera.
The enzyme helicase unwinds the DNA duplex. Which of the following is likely to be true?
A) A pre-existing 3'OH is required for helicase to work
B) Helicase uses energy from ATP Hydrolysis
C) Helicase is itself made of RNA
D) Energy is released when the DNA helix is unwound.
Answer:
B) Helicase uses energy from ATP Hydrolysis
Explanation:
Helicase's primary function is to separate the annealed nucleic acid strands. It is a motor protein and moves directionally along the phosphodiester backbone. It usually separates strands of double helix DNA or self annealed RNA. It used the energy from ATP hydrolysis and breaks hydrogen bonds between nucleotide bases.
In human body 95 types of helicases are found. They have sequence motifs required for ATP binding, ATP hydrolysis and translocation along nucleic acid phosphodiester backbone. The variable portion in their amino acid sequence imparts specific feature to each helicase.
During sexual reproduction, novel mixtures of alleles are generated. Why is this?
a. in all diploid species, two alleles exist for every gene
b. a diploid individual has two different alleles for every gene
c. every gamete produced by a diploid individual has several different alleles of a single gene
d. during meiosis, the segregation of homologs is not random and different gametes end up with similar alleles of each gene
e. none of the above
Answer:
e. none of the above
Explanation:
Prophase-I of meiosis I include the pairing of homologous chromosomes followed by alignment of these pairs on the cell's equator in metaphase I.
During anaphase-I, the homologous chromosomes are separated from each other and begin to move towards opposite poles. Each homologous pair of chromosomes consists of one maternal and one paternal chromosome carrying corresponding alleles for the genes.
The separation of these homologous chromosomes during anaphase-I is random which means that each member of a homologous pair is randomly distributed to one of the poles. The independent separation of homologous chromosomes to the opposite poles results in unique allelic combinations in gametes.
What is the difference between cardiac and skeletal muscle cells?
Answer:
-The skeletal muscle has long and cylindrical cells. The cardiac muscle cells are short and together they form a branch.
-The heart muscle fibers have only one nucleus in the center. The skeletal muscle fibers are multinucleated.
-The skeletal muscle is voluntary and the cardiac is involuntary.
- Sarcoplasma and glycogen are more abundant in the heart muscle.
-The cardiac muscle is longitudinal striated and the skeletal is transverse striated
Make connections Which chemical group is most likely to be responsible for an organic molecule behaving as a base (see Concept 3.3)?
a. hydroxyl
b. carbonyl
c. amino
d. phosphate
Answer:
The correct answer will be option-C.
Explanation:
The functional groups are the group of atoms which gets attached to the skeleton of carbon in a molecule and provides certain characteristics to the molecule. The main functional group includes hydroxyl, carboxyl, amino, phosphate, methyl carbonyl and sulfhydryl.
These groups could be acidic or basic depending upon them if their structure will be able to take H⁺ ions from solution or donate H⁺ ions. In the given question, the basic group among these is an amino group which has the ability to accept H⁺ ions from the solution and form NH₃⁺ ions.
Thus, Option-C is the correct answer.
The genetic information contained in DNA consists of a linear sequence of coding units, known as codons. Each codon consists of three adjacent DNA nucleotides that correspond to a single amino acid in a protein. The E. coli DNA molecule contains 4.70×1064.70×106 base pairs. Determine the number of codons that can be present in this DNA molecule.
Answer:
The correct answer is 1.57 × 10⁶ codons.
Explanation:
It is given that the number of base pairs in E.coli DNA is 4.70 × 10⁶
1 codon = 3 DNA nucleotide adjacent that codes for a single amino acid
The number of bases or nucleotides in a single strand = number of base pairs in DNA = 4.70 × 10⁶
We only have to consider the coding strands triplet codons, that is,
Number of triplet codon = 4.70 × 10⁶ / 3
= 1.57 × 10⁶ codons.
How does eating influence high density lipoproteins (HDL) in the body?
Answer: The element with the greatest influence on cholesterol levels is the fat content of food. Not only the amount of cholesterol, but also the type of fat.
Explanation:
Cholesterol is a type of fat found in the body, which is used to make hormones and vitamin D. The liver makes cholesterol to handle these tasks, but cholesterol can also be incorporated into the body through foods such as meat, dairy, and poultry. If you consume a lot of these, the cholesterol levels could become too high.
There are two types of cholesterol:
High-density lipoprotein (HDL) or “good cholesterol”. It transports the excess of cholesterol to be expelled so it wont end up in the arteries. Low-density lipoprotein (LDL) or “bad cholesterol”. It transports cholesterol to the arteries, where it may collect in artery walls. This could lead to a buildup of plaque known as atherosclerosis which can increase the risk of blood clots and if one of them breaks away and blocks an artery, it could cause a stroke or heart attack.If there is a predominance of saturated fatty acids in the fat of the diet, a rise in serum cholesterol and LDL-cholesterol is caused. To lower the bad cholesterol, you should limit foods such as milk fats, fatty meats or sausage and include more fibre in your diet. On the other hand, polyunsaturated fatty acids - for example, those present in seed oils or fish - produce their reduction. Monounsaturated fatty acids, such as those provided by olive oil, act like polyunsaturated ones and, in addition, tend to raise HDL-cholesterol, so their use entails a greater benefit.
5) Strawberry plant clones are given different amounts of water for a 3-week period. First strawberry plant
receives 400 millilitres (ml) a day. The second strawberry plant receives 200ml a day. The third strawberry
plant receives 100ml a day. The fourth strawberry plant does not receive any extra water; this plant only
receives natural ways of receiving water. The height of the strawberry plants is recorded daily.
IV :
DV :
CG :
Con :
Answer:
IV: Amount of water
DV: Height of the strawberry plant
CG: The fourth strawberry plant
Explanation:
The Independent Variable is the amount of water given to the strawberry plants; the Dependent Variable is the height of the strawberry plants; the Control Group is the fourth strawberry plant that only receives natural ways of water, without any extra water treatment.
What information does this experiment include?In an experiment with strawberry plant clones, different amounts of water are provided to observe their effect on plant height. The amount of water is the independent variable (IV), while the height of the plants is the dependent variable (DV).
One plant receiving no extra water serves as the control group (CG) for comparison. Constants include the experiment's duration, environmental conditions, plant type, measurement method, and initial plant height. This investigation aims to understand the impact of water availability on plant growth.
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What do B cells do when they identify a pathogen?
A. Engulf and eat it
B. Kill it
C. Produce antigens to bind to the pathogen and memory cells to guard against future infection.
D. Produce antibodies to bind to the pathogen and memory cells to guard against future infection.
E. Engage helper T cells to fight the infection
D
Explanation:
With the help T cells , B cells make special proteins called antibodies which stick to antigens on surface of germs stopping them in their track.
Banana plants, which are triploid, are seedless and therefore sterile. Propose a possible explanation.
Answer:
The correct answer will be- homologous chromosomes fail to pair.
Explanation:
The seedless variety of the banana are triploid that is each cell contains three copies of the chromosomes. The triploid variety of the organism is considered sterile or not able to produce offspring as they are unable to generate gametes for fertilization.
The formation of gametes relies upon a type of cell division called meiosis which proceeds in four phases of karyokinesis stage.
At metaphase of the meiosis, chromosomes fail to pair at the equatorial plate as two chromosomes pair leaving one extra chromosome which is not paired. The gametes are produced with unequal chromosomes and on fertilization zygote is not formed.
Thus, homologous chromosomes fail to pair is the correct answer.
How is a spider web like a food chain?
Answer:
food webs are drawn in a diagram similar to a spider web
Briefly, in two to three sentences, contract the functions of innate, humoral, and cell-mediated immunity.
Answer:
Innate immunity includes non-specific immune responses to prevent the entry of pathogens and to kill the entered pathogen by first line of defenses.
Humoral immunity kills the entered pathogens by production of antibodies specific to the particular type of antigen. B lymphocytes are central to the humoral immunity.
Cell mediated immunity is another type of adaptive immune response wherein the killer T cells directly kill the infected cells.
Explanation:
Cell-mediated immunity is provided by killer T cells against virus-infected cells, foreign cells, and cancer cells. The cytotoxic T cells directly kill the entered pathogens.
Antibody-mediated immunity refers to the specific resistance to disease-causing agents. It includes the production of specific antibodies by B lymphocytes. it is also called humoral immunity.
Innate immune responses are the nonspecific immune responses that prevent the entry of all the diseases causing pathogens and antigens into the body. It includes the first line of defenses such as skin and mucous membranes as well as phagocytes and natural killer cells that kill all the pathogens and antigens non-specifically.
Which process is most directly driven by light energy?
(A) creation of a pH gradient by pumping protons across the thylakoid membrane
(B) reduction of NADP+ molecules
(C) transfer of energy from pigment molecule to pigment molecule
(D) ATP synthesis
Answer:
C
Explanation:
The energy from sunlight is used to split water molecule into H+ and O- and the emanating electron used to replace the lost electron at the reactive center of the Photosystem I & II. The lost electron is a high energy electron that is transferred from pigment to pigment in the Photosystem. As it does, its energy is harnessed and used to pump H+ protons into the lumen of the thylakoid from the stroma (creating a proton motive force that will be used to make ATPs). Ultimately this electron will then reduce NADP to NADPH.
The process that is most directly driven by light energy is ; ( C ) Transfer of energy from pigment molecule to pigment molecule
The light energy derived from the sunlight or a corresponding light source splits the H⁺ and O⁻ contained in water molecules. The split O⁻ replaces the electron which is lost at the center of photosystem I and II.
The lost electron at the reactive center contains energy while it is been transferred from one pigment molecule to another pigment molecule and this driven directly by the light energy.
Hence we can conclude that the process that is most directly driven by light energy is Transfer of energy from pigment molecule to pigment molecule.
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Explain why cytotoxic T cells are not affective against bacteria.
Answer:
Because cytotoxic T cells are activated with antigens.
Explanation:
Cytotoxic T cells are a type of white blood cell that expresses T-cell receptors that can recognize specific antigens to then be activated by them to neutralize an infected cell, antigens are structures that can stimulate an immune response, they are presented by the cells so T cells can identify them.
So, based on the previous information, cytotoxic T cells can't recognize or attack bacterias if their T cell receptors don't have an antigen presented by another cell to bind.
I hope this information clarifies your doubts!
Assume that the structural genes of the lac operon have been fused, through recombinant DNA techniques, to the regulatory apparatus of the ara operon. If arabinose is provided in a minimal medium to E. coli carrying this gene fusion, would you expect β-galactosidase to be produced at induced levels? Why?
Answer:
The correct answer is "Yes, β-galactosidase would be produced at induced levels".
Explanation:
The L-arabinose operon, also known as ara operon, is activated in the absence of glucose and in the presence of arabinose. In this study the ara operon was fused with the lac operon, therefore arabinose would active not only the genes of ara operon but also lac operon. Once the researchers provide E. coli with arabinose, the bacteria would produce β-galactosidase as a result of lac operon activation.
According to the punctuated equilibria model,
a. given enough time, most existing species will branch gradually into new species.
b. most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species.
c. most evolution occurs in sympatric populations.
d. speciation is usually due to a single mutation.
Answer:
b. most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species
Explanation:
Species can evolve fast or slowly. When species accumulate changes at a slow rate this is called gradualism.
If a species suddenly has a an enormous change for example through mutations in the genes of a few individuals or a single individual the species can has evolve and may become suddenly a new one. A good example can be found in the following link: https://blog.education.nationalgeographic.org/2018/02/07/cloned-crayfish-are-taking-over-the-world/
the article provides evidence of sudden changes that may lead to speciation in at a really fast rate.
The most accurate statement is: 'most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species'. So, option b is true.
Explanation:According to the punctuated equilibria model, the most accurate statement is: 'most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species'. This model suggests that evolution happens in rapid bursts, interspersed with long periods of stability, often called stasis. Essentially, a species experiences little evolutionary change for most of its existence until a sudden shift in its environment or population pressures spur a rapid period of adaptation and evolutionary change, leading to the formation of a new species. Hence, this model disputes the idea that evolution is a slow, gradual process happening over a long period, a theory known as gradualism.
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Which of the following statements concerning photosynthesis is NOT true?
a. Photosynthesis occurs in the chloroplast
b. In photosynthesis, CO2 is reduced
c. During photosynthesis, the hydrogen carrier is NAD
d. During photosynthesis, O2 is released
Answer: c. During photosynthesis, the hydrogen carrier is NAD
Explanation:
The photosynthesis is a process that occurs in the chloroplast organelle of the plant cells. The typical light reaction of the photosynthesis takes place inside the thylakoid membrane of the chloroplast. The chief reactants such as water and carbon dioxide participate in the reaction. The water gets oxidized in the reaction to release the oxygen as a product. The carbon dioxide get reduced.
The light accepted by the pigment chlorophyll in the chloroplast basically transfers the electron and hydrogen from water to the acceptor that is called as NADP⁺.
Answer:
c. During photosynthesis, the hydrogen carrier is NAD
Explanation:
The co-factor during photosynthesis is Nicotinamide Adenine Dinucleotide Phospahte .(NADP), and not NAD.The latter is a coenzyme in cellular respiration for ferrying H+(as NADH+) together with FADH+ from Kreb's Cycle into the matrix of mitochondria for oxidative phospshorylation, needed for ATPs synthesis,
NADPH is a co-factor, needed as reducing agent in photosynthesis's cyclic and non cyclic photophosphorylation reactions.Therefore option C is not true.
What kind of bonds connect the bases of DNA to each other?
a. ionic
b. hydrogen
c. covalent
d. van der Waals
e. protonic
Answer:
The correct answer will be option-B.
Explanation:
Deoxyribose nucleic acid or DNA is the genetic material of the organism which is made up of nucleotide monomer. Each monomer is made up of a five-carbon deoxyribose sugar, a phosphate group and four different nitrogenous bases.
The nitrogenous bases- purines (adenine and guanine) bond with pyrimidines (cytosine and thymine) via hydrogen bond between them. The hydrogen bonds are weak bonds but establish the DNA structure.
Thus, Option-B is the correct answer.
The bases of DNA are connected by hydrogen bonds.
Explanation:The bases of DNA are connected to each other by hydrogen bonds. These bonds form between specific complementary base pairs: adenine (A) with thymine (T) and guanine (G) with cytosine (C). Hydrogen bonds are relatively weak compared to covalent bonds, but they are crucial for maintaining the structure of the DNA helix.
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When a large number of species, sometimes entire major taxa, go extinct in a short period of time on the geological scale, the cause is usually
A. Competition with other species
B. A large forest fire
C. Radical global climate change
D. Predation by a new type of hunter
Answer: C. Radical global climate change.
Explanation:
The entire taxa of the species can be wiped out due to an large catastrophic event associated with the change in the climate. As the climate becomes warm the chances of undergoing the global precipitation rate will change. The climate being an important abiotic factor under unstability is likely to affect the amount of rainfall, snow fall, drought and conditions of desertification. All these factors can be responsible for the removal of the entire taxa of the species in short time.
Describe the substrate specificity of chymotrypsin and the structural feature that determines this specificity.
Answer:
The main substrate of chymotrypsin includes tryptophan, tyrosine, phenylalanine and methionine
Explanation:
1.
Histidine yields a proton to aspartate and recovers it from serine.
Seen in another way: aspartate captures a proton from the serine through histidine.
2.
a) The serine (deprotonated) is thus capable of attacking the peptide bond (nucleophilic carbonyl attack) and forms a tetrahedral intermediate; The substrate is thus covalently bound to the enzyme (now it is a transition state).
b) The peptide bond is broken and the released amino terminus (R) recovers a proton from histidine.
c) Histidine, in turn, recovers it from aspartic.
3.
a) Aspartate captures a proton of histidine again, so that it can capture it in turn from water.
b) This generates a hydroxide anion that attacks the ester intermediate between the serine and the carboxyl part (R ′) of the substrate peptide.
c) A new tetrahedral intermediate bound to the enzyme is formed (via serine residue).
4.
a) The carboxyl group of the peptide is regenerated, the serine being separated and the other peptide fragment being free (the R ′ part with a free carboxyl end)
b) The serine recovers the proton at the expense of histidine, which in turn captures it from aspartic acid.
c) The catalytic triad (Asp, His, Ser) has been regenerated in its original state.
The net reaction is:
R–NH – CO –R ′ + H2O ⟶ R– NH2 + HOOC –R ′ ⟶ R – NH3 + + −OOC –R ′
The active site or catalytic center of chymotrypsin is formed by several amino acid residues, among which the essential role corresponds to the "catalytic triad".
Calculate the volume of buffer to which 500mL of 60 mM potassium chloride solution must be diluted to make a new concentration of 0.001M.
Answer:
[tex]30,000[/tex] mL
Explanation:
Given -
Volume of buffer [tex]= 500[/tex] mL
Concentration of solution [tex]= 60[/tex] mM[tex]= 0.06[/tex]M
New concentration of the solution [tex]= 0.001[/tex]M
As we know
[tex]C_1* V_1= C_2*V_2[/tex]
Where
[tex]C_1, C_2[/tex] are the concentration of the solution before and after dilution.
And [tex]V_1, V_2[/tex] are the volume of solution before and after dilution.
Substituting the given values in above equation, we get -
[tex]500* 0.06 = V_2* 0.001\\V_2 = \frac{30}{0.001} \\V_2 = 30,000[/tex]mL
Explain how the independent alignment of homologs, and also crossing-over during the first meiotic division, each contribute to the genetic diversity of gametes.
Answer: Homologous chromosomes are randomly distributed to daughter cells, this means different chromosomes segregate independently of each other. And they exchange segments of DNA during crossing over. This recombination creates genetic diversity because genes from each parent are exchanged.
Explanation:
Meiosis is a type of cell division that produces gamete cells, which are sex cells (egg and sperm)
Chromosomes that form a pair and are found together are called homologous chromosomes, and they are inherited from each parent. During prophase of meiosis I, the homologous chromosomes exchange segments of DNA in a process called crossing over. This recombination creates genetic diversity because genes from each parent are exchanged. It results in new combinations of genes on each chromosome.
After that, during the anaphase of meiosis I, the two chromosomes line up on the equatorial plane of the cell. Then, they are separated and each will go to a new daughter cell. So homologous chromosomes are randomly distributed to daughter cells, this means different chromosomes segregate independently of each other.
The underlying structure of DNA is very simple, consisting of only four possible building blocks. a. How is it possible for DNA to carry complex genetic information if its structure is so simple? b. What are these building blocks? Can each block be subdivided into smaller units, and if so, what are they? What kinds of chemical bonds link the building blocks? c. How does the underlying structure of RNA differ from that of DNA?
Answer and Explanation:
a) Although the DNA is made up of only four possible building blocks, these blocks are combined from a 3 (form triplets of nitrogenous bases) giving rise to a large variety of nucleotide sequences that carry a large amount of genetic information.
b) DNA is a polymer formed by nucleotides, which we could consider as the building blocks.
Each of these nucleotides is, at the same time, formed by a carbohydrate, a nitrogenous base and a phosphate group (derived from phosphoric acid). The nitrogen base may be adenine (A), thymine (T), cytosine (C) or guanine (G).
The nitrogenous bases are located in a complementary manner between the two strands of DNA, with thymine-adenine being joined by a double bridge of hydrogen and cytosine-guanine by three hydrogen bonds.
Example of questions A and B: AAA, AAT, AAC, AAG, ATT, ACC, AGG, ATA, ACA, AGA, etc.
c) In RNA the carbohydrate that is present is ribonucleic acid while in DNA it is deoxyribonucleic acid.
In addition, in the RNA, the thymine nitrogenous base is replaced by the Uracil.
Write a one page note on sex linked inheritance with 2 examples briefly explained.
Answer:
Sex linked inheritance may be defined as the type of inheritance in which the trait or mutation is present on X chromosomes rather than on autosomes. Sex linked trait expression will depend upon the type of sex.
Two type of inheritance of sex linked trait are X linked dominant and X linked recessive trait. In X linked recessive trait, the male are more affected as they have only single X chromosome. Females should have both X chromosome affected for the expression of the trait. In sex linked dominant trait, a single X chromosome is enough for the expression of trait.
For example: Color blindness is an sex linked recessive trait, the mother generally passes the trait to their sons. Fragile X syndrome is a sex linked dominant trait in which the affected father will have all the affected daughter.
Which of the following can contribute to infertility in a young male body builder taking anabolic steroids?
a. suppression of LH release from the pituitary
b. decreased circulating levels of dihydrotestosterone (DHT)
c. increased muscle mass
d. decreased testicular testosterone concentrations
e. B and D
Answer:
The correct answer is a. suppression of LH release from the pituitary.
Explanation:
Anabolic steroids are synthetic steroids made up of mainly androgenic hormone like testosterone. These anabolic steroids are usually taken by young male bodybuilders because it helps in gaining muscles.
These anabolic steroids have many side effects and infertility in males is one of its side effects. Excessive use of these steroids stops the secretion of gonadotropic hormones such as LH in males from pituitary glands by inducing negative feedback to the pituitary.
LH is important in the production of testosterone from Leydig cells and testosterone is important for sperm production. Therefore if LH is stopped no sperm production will occur and it leads to infertility in males.