Answer:
True
Explanation:
Testosterone is the primary male sex hormone. It is produced by the Leydig cells of the testis. The testosterone produced by both males and females. The amount is more male than females. In females, testosterone is in the form of androgen hormone.
The anterior pituitary secretes 2 hormones i.e. LH and FSH. The luteinizing hormone from the pituitary gland enters into the interstitial space of the testis. In the interstitial space, Leydig cells are present, which are the target organ for LH. The LH stimulates the Leydig cells to produce testosterone. Hence Leydig cells are also called interstitial cells.
Testosterone secretes from the Leydig cells of the testis and mixes with the bloodstream. It produces in the presence of LH. Then it reaches to different cells of the body by the bloodstream. Testosterone maintains bone and muscle growth, induces the secondary sexual characters.
When testosterone level is high in the blood, it sends a signal to the brain to decrease the secretion of testosterone. This is the negative feedback mechanism of testosterone.
When the corpus luteum degenerates
A. Circulating levels of estrogen and progesterone rapidly decline.
B. FSH and LH secretion start to rise as the inhibitory effects of the gonadal steroids are withdrawn.
C. The endometrium sloughs off.
D. Both A and B are correct.
E. All of the preceding are correct.
Answer:
E. All of the preceding are correct
Explanation:
When the corpus luteum stops secreting progesterone and estrogen, the
Concentration of these hormones in the blood drops.
As a result, small arteries in the endometrium contract, reducing
the oxygen supply. Menstruation, which marks the beginning
of a new cycle, begins when cells die (due to the lack of oxygen) and blood vessels break and bleed. Estrogen concentrations and
Progesterone are now too low to inhibit the anterior pituitary,
so the secretion of HSF and HL grows again.
The light reaction of photosynthesis does not include
A) chemiosmosis
B) oxygen liberation
C) charge separation
D) electron transport
Answer:
The correct answer will be option-C.
Explanation:
Photosynthesis is a complex process which converts light energy into chemical energy which is used to form the glucose molecule. Photosynthesis occurs in two stages: light-dependent and light-independent reaction.
The light-dependent reaction is the reaction which takes place in the sunlight and converts light energy to chemical energy in ATP and NADPH molecules.
The light-dependent begins when photosystem absorbs light energy which causes the excitation of the electrons provided by chlorophyll molecule. The excited electrons get accepted by electron acceptor molecule and a chain of electron flow begins called electron transport chain.
This creates a scarcity of electron in photosystem which causes hydrolysis of the water molecule as a result oxygen gas is released. The electron flow leads to the synthesis of ATP molecules through chemiosmosis.
Thus, Option-C is the correct answer.
Where in an angiosperm would you find a megasporangium?
a. in the style of a flower
b. enclosed in the stigma of a flower
c. within an ovule contained within an ovary of a flower
d. packed into pollen sacs within the anthers found on a stamen
Answer:
Within an ovule contained within an ovary of a flower (Ans C).
Explanation:
Angiosperm is known as flowering plants and bears their seeds within a fruit. They are vascular plants they have stem, leaves, and roots. They represent approximately 80% of all living green plants. They are the most abundant and diverse plants throughout the globe.
Angiosperms are vascular seed plants where the ovule or egg is fertilized and develops into the seed in an enclosed hollow ovary. The ovary is also enclosed in a flower, it is the part of the plant angiospermous plant which contains both male or female reproductive organs. Fruits are derived from the maturing flower organs present in the angiosperm plants.
They are also defined as vascular plants with fruit, seeds, and flowers for reproduction.
Which of the following does NOT belong with the others?
a. canine
b. dentin
c. enamel
d. pulp
e. crown
Answer:
a. canine
Explanation:
a. Canine does not belong with the other because of canine a type of teeth while others are the components of a particular tooth.
Canines are single-rooted, strong and pointed teeth. Total four canines are found in a human used for tearing the food or anything.
b. Dentin is hard tissue which is located inside the enamel of a teeth.
c. Enamel is the outer most part of a tooth known as hardest part of the body.
d. The pulp is a space inside a tooth where blood vessels and nerves take place.
e. Crown, is the visible portion of a tooth in the mouth.
Meiosis provides for or leads to several different forms of genetic variation. For example:
a. it maximizes the mutation rate of DNA
b. it minimizes the mutation rate of DNA
c. it changes individual chromosomes through the process of "crossing over
d. it changes individual chromosomes through the process of nonrandom mutation
e. it doubles the number of chromosomes that were present at the beginning of the process
Answer:
a. it maximizes the mutation rate of DNA
Explanation:
b. False
In fact, it maximizes due to the crossing over process that occurs in metaphase.
c. False
"Crossing over" doesn't change the chromosomes individually, but in homologue pairs.
d. False
It is a random process
e. False
It doesn't double the number of chromosomes, but the genetic load
An organism has the following characteristics: low biotic potential; k-selected, iteroparous; heterotrophic, fed upon by top carnivores large body size (> 2m tall). This organism most likely would also have
a. seed cones
b. basidiocarps
c. exoskeleton
d. open circulatory system
e. vertebrae
Answer:
e. vertebrate
Explanation:
The question states that the organism posses the following characteristics:
Low biotic potential: this means that the maximum amount of offpring that this species can produce under best environmental conditions is actually low. Typically, large organisms have much lower biotic potential than smaller ones. k-selected: this means that this species typically invest much more in fewer offspring rather than prioritizing many offspring.iteroparous: means that can reproduce many times over one organisms's lifetime.heterotrophic, fed upon by top carnivores large body size (> 2m tall): this shows that they are preys of large carnivores, thus it implies that the prey itself has a considerable size and it is not a plant.Option a is discarded as seed cones are produced by conifers which are autotrophics.
Option b is incorrect as basidiocarps are typical of Basidiomycetes (fungi) which are not large and are rarely consumed by carnivores.
Option c and d correspond to small animals (e.g. arthropods) and with usually high biotic potential and r-selected species which prioritizes high growth population rates and offspring.
Then, option e (vertebrate) is consistent with belong to a k-selected, low biotic potential, iteroparus, heterotrophic species (e.g. a mammal).
How many genetically different eggs could be formed by women with the following genotypes? (a). Aa bb CC DD (b). AA Bb Cc dd (c). Aa Bb cc Dd (d). Aa Bb Cc Dd
Answer:
(c). Aa Bb cc Dd
Explanation:
The number of genetically different eggs that could be formed by women with the following genotypes are a) 5 b) 6 c) 7 d) 8.
What is meant by independent assortment?
The Principle or the law of Independent Assortment describes how different genes separate independently from one another during the development of reproductive cells or germ cells. An Independent assortment of genes and the traits corresponding to this was first observed by Gregor Mendel in the year 1865 when he was studying genetics in pea plants.
Mendel performed the experiment called dihybrid cross. In this, he performed a between organisms which are different with regard to two traits. His discovery was that when traits combine in the offspring, the cross does not always match the combinations of traits according to the parent organisms. From his data, he could formulate the Principle of Independent Assortment.
Therefore, according to the principle of independent assortment, the number of genetically different eggs that could be formed by women with the following genotypes are a) 5 b) 6 c) 7 d) 8.
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Bird guides once listed the myrtle warbler and Audubon’s warbler as distinct species. Recently, these birds have been classified as eastern and western forms of a single species, the yellow-rumped warbler. Which of the following pieces of evidence, if true, would be cause for this reclassification?
a. The two forms interbreed often in nature, and their offspring survive and reproduce well.
b. The two forms live in similar habitats and have similar food requirements.
c. The two forms have many genes in common.
d. The two forms are very similar in appearance.
Answer:
a. The two forms interbreed often in nature, and their offspring survive and reproduce well.
Explanation:
A species is a group of organisms that can breed with each other and reproduce viable offsprings that are also capable of reproducing in future.
Here, Audubon's warbler and Myrtle warbler had separate habits which might or might not be similar. Their food requirements also might or might not be similar. But they were found to interbreed and give rise to offsprings who survived and reproduced well so they belonged to the same species of yellow rumped warbler.
Beadle and Tatum's concept of the gene has been further refined to state which of the following most correct and current idea?
a. one gene - one enzyme
b. one gene - one polysaccharide
c. one gene - one metabolic block
d. one gene - one allele
Answer:
a. one gene - one enzyme
Explanation:
Genes are connected to enzymes was first suggested by Sir Archibald Garrod. Later on, Beadle and Tatum carried out genetic studies on Neurospora and confirmed Garrod's hypothesis.
The link between genes and enzymes was called “one gene-one enzyme hypothesis”.
But this hypothesis is not accurate and changed because some proteins are encoded by genes are not enzymes. Some genes do not encode a whole protein but a subunit of a protein. In general, one polypeptide (a chain of amino acids) encoded by one gene.
2. Hepatitis D is a defective form of the virus that needs Hepatitis B to exist.
A) True
B) False
Answer:
The given statement is true.
Explanation:
HDV or hepatitis D virus refers to a virus, which needs hepatitis B virus for its replication. The HDV infection takes place concurrently or as super-infection with hepatitis B virus. About five percent of individuals with chronic HBV infection are co-infected with HDV, causing a sum of 15 to 20 million individuals infected with HDV globally.
The co-infection of HDV-HBV is regarded to be the most extreme kind of chronic viral hepatitis because of the rapid cases of liver-associated death and hepatocellular carcinoma. The infection of hepatitis D can be prevented with the application of hepatitis B vaccines.
Present an overview of two classical experiments that
demonstrated that DNA is the genetic material. Can RNA be the
genetic material? Explain.
Answer:
Explanation:
A) Fredrick Griffith Bacterial Transformation Experiment
In 1928 Fredrick worked on various strains on Staphylococcus pneumoniae
and mice.
He was trying to develop a vaccine against pneumonia.
He chose two strains of bacteria,
R stain- rough and non virulent strain
S strain- smooth and virulent strain
when he injected the strains one by one into the mice these were the results-
R strain into the mice -----> Mice lives
S strain into the mice ------> Mice gets pneumonia and dies
Heat killed S strain ------> Mice lives
R starin + Heat killed S strain----> Mice dies
Thus, Griffith concluded that The living R strain must have taken a 'transforming principle' from the heat killed S train and became virulent. This resulted in the death of the mice.
B) Hershey Chase experiment
They used bacteriophages to conduct this experiment. Their phase was made up of protein and contained DNA.
To determine that whether the phage added proteins or DNA to the host cell in order to multiply, he radiolabeled the components of the phage
Proteins were labelled by 35S
DNA was labelled with 32P
He infected various batches of bacterial culture with these radiolabelled bacteriophage.
Then he centrifuged the culture and got a pellet( heavy material like bacteria) and supernatant( light material like media, phages).
He found that pellet was mostly labelled with 32P and not 35S. Hence they concluded that it DNA and not protein were the genetic material.
RNA stores the genetic material. In fact RNA was the first genetic molecule and it was only after evolution that DNA became the genetic molecule.
-RNA has a great capacity of storing and expressing the genetic information.
-But the single stranded structure of RNA is unstable and can be easily destroyed by the enzymes.
-Hence the double stranded nature of DNA is much more stable and and passes the genetic information with more accuracy.
Some bacteria may be able to respond to environmental stress by increasing the rate at which mutations occur during cell division. How might this be accomplished? Might there be an evolutionary advantage of this ability? Explain.
Answer:
All the organisms has developed some methods to respond towards the changing environment. Bacteria also develops some mechanism by which they are able to tolerate the external environment.
Some bacteria respond towards environment by increasing the rate of mutation. This mutation can be accomplished as it creates the formation of oncogenes in the bacteria. The cyclins and kinases of cell cycle gets mutated that leads to the uncontrolled growth of cell bacteria. This produces an evolutionary advantage to bacteria as it allows the bacteria to grow in the hostile environment. For example: the development of resistant strain of bacteria towards a specific drug.
Bacteria can increase mutation rates during cell division to adapt to environmental changes, using mechanisms like genetic recombination, bacterial conjugation, and adaptive mutation. By doing so, they can rapidly evolve, leading to the emergence of antibiotic-resistant bacterial strains. However, these mutations do not arise directly in response to environmental changes, rather pre-existing genes within the bacterial population are selected for survival.
Explanation:Bacteria may increase the rate of mutations during cell division to respond to environmental stressors such as exposure to antibiotics. This is accomplished via mechanisms like genetic recombination, bacterial conjugation, and adaptive mutation, which can alter the genetic composition of the bacteria, allowing them to adapt to new conditions.
For instance, in mechanisms like genetic recombination and bacterial conjugation, bacteria exchange genetic material to increase genetic diversity, allowing them to respond more adaptively to environmental changes. Adaptive mutation meanwhile, allows organisms to undergo mutations to adapt to stressful conditions.
Such genetic variability combined with a short generation time, allows bacteria to evolve rapidly, leading to the emergence of antibiotic-resistant bacterial strains. This rapid adaptability gives bacteria a significant evolutionary advantage as it improves their survival in hostile environments.
However, it is vital to note that while increased mutation rates can lead to antibiotic resistance, these mutations do not arise in direct response to environmental changes, such as the introduction of antibiotics. Instead, pre-existing genes within the bacterial population are selected for survival under such conditions.
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Albinism is a condition in which pigmentation is lacking. In humans, the result is white hair, non-pigmented skin, and pink eyes. The trait in humans is caused by a recessive allele. Two normal parents have an albino child. What are the parents' genotypes? What is the probability that the next child will be albino?
Answer:
1/4 or 25% chance/ probability of having an albino child.
Explanation:
Albinism is a recessive trait, this means that a person need 2 copies of the allele to express this condition. If both parents are normal their genome must be Aa ("A"=normal condition and "a" recessive allele) when they produce gamets they could either be "A" or "a" but when fertilization happens there's a 25% chance of 2 gametes with the recessive trait to meet, hence producing an albino.
It is important to understand that this is only probability. A couple could have 6 children and all of them could be normal.
What are the four main human activities that cause a loss of biodiversity?
a. Preservation, habitat destruction, overharvesting, and use of chemical pollutants
b. Habitat destruction, invasive species displacement, use of chemical pollutants, and overharvesting
c. Overharvesting, conservation, use of chemical pollutants, and invasive species displacement
d. conservation, preservation, use of chemical pollutants, and overharvesting
e. Habitat destruction, overharvesting, conservation, and use of chemical pollutants
Answer:
The correct answer will be option-B.
Explanation:
Biodiversity represents the variety of the biological organism-form microorganism to plant and animals in any particular habitat.
The biodiversity loss is a serious problem in the modern world which is caused by the growth rate of humans and resource exploitation.
Humans depend on the natural resources for their use due to which they modify the natural area leading to the habitat loss. They over-harvest the natural resources like aquatic organisms mainly fishery industry.
The growth rate of humans has forced us, humans, to increase productivity in every area sue to which humans use harmful chemicals like pesticides and insecticides which directly affect biodiversity. it leads to algal bloom and eutrophication of small water bodies.
The introduction of exotic species to any area results in the displacement of the invasive species of the area which directly affects the natural habitat.
Thus, Option-B is the correct answer.
Answer:
The Correct answer is B
Explanation:
The loss of biodiversity can be focused on the activities of Human beings on the world's ecosystem which is the major cause of its loss.Overexploitation of natural resources is the human activities which are the major cause of biodiversity loss.Population growth and overconsumption is one of the major cause of Human activity which is responsible for the loss of Biodiversity.Which of the following does NOT contribute to genetic variation among plants?
a. Flowering time
b. An increased number of chromosomes
c. Mutations
d. Genetic recombination
Answer:
The correct answer will be option-A.
Explanation:
Genetic variation is the difference in the DNA sequences of individuals in a population. Genetic recombination is the main reason for the diversity of organism on earth.
The genetic variation takes place during gamete formation by recombination of DNA sequences which takes place during prophase of meiosis I.
Since genetic variation involves changes in the coding segments of the DNA called genes which leads to mutations, therefore, flowering time does not influence the genetic variation and option-A is the correct answer
___________ is a molecule that picks up electrons from NADH dehydrogenase and delivers it to cytochrome C reductase
a. Ubiquinone
b. Quinone
c. dehydrogenase
d. ATP synthase
Answer:
Ubiquinone.
Explanation:
Electron transport chain is the important cycle in which electrons are transferred are from one complexes to another complexes and couples it with proton transfer. This is important for the formation of ATP molecule.
Ubiquinone acts as a mobile carrier in the electron transport chain. The ubiquinone accepts electron from the NADH dehydrogenase. The accepted electron is then transferred to the complex III ( cytochrome C reductase). Both oxidation and reduction occur in this step.
Thus, the correct answer is option (a).
Cells of plants and animals have _____________.
a. central vacuole and mitochondria
b. cell membrane and cell wall
c. chromosomes and chloroplasts
d. nucleus and DNA
Answer:
cell membrane and cell wall
The anticodon of a particular tRNA molecule is
a. complementary to the corresponding mRNA codon.
b. complementary to the corresponding triplet in rRNA.
c. the part of tRNA that bonds to a specific amino acid.
d. catalytic, making the tRNA a ribozyme.
Answer:
The anticodon of a particular tRNA molecule is a. a complementary to the corresponding mRNA codon. Below, I let you an explanation of how DNA translation ocurrs as a complement to your study.
Explanation:
The translation of the genetic code is a process in which RNA becomes an amino acid junction to form a protein. This is a process which is divided into three parts: initiation, elongation and termination.
In the Initiation stage the ribosome binds with the mRNA and the first tRNA so that translation can begin.
Initiation :
For this process it is necessary to have:
• A ribosome (specialized organelle)
• An mRNA which carries the instructions
• A "start" tRNA that carries the first protein amino acid
When these three things come together, the initiation complex is formed, which will begin the formation of proteins. For this process it is necessary that the cell provides energy in the form of guanosine triphosphate (GTP )
Elongation occurs when the polypeptide chain increases in length.
In the ribosome there are several specialized places for each function. The first tRNA, which carries methionine, is located in the center of the ribosome space in a place called site P. Next to this site, a new codon is exposed, in another space and is called site A. Site A will be the location space for the next tRNA, whose codon is complementary to the codon that is exposed. This means that each tRNA is accompanied by auxiliary proteins, and only one tRNA that binds perfectly will be "released" at site A. To release the tRNA, a molecule that stores energy mentioned above, guanosine triphosphate (GTP) is used.
After the corresponding tRNA is located at site A, the formation of the peptide bond is given which is responsible for connecting one amino acid to another.
Termination occurs when a stop codon in the mRNA (UAA, UAG, or AGA) enters site A. Here release factors read the termination codons and are located at site P these release factors interfere with the function of the enzyme responsible for forming the peptide bonds then finally the tRNA chain is separated, and the newly dormant protein is released
The anticodon of a particular tRNA molecule is complementary to the corresponding mRNA codon. The correct option is A.
When protein synthesis is taking place, the anticodon of a tRNA molecule is a three-nucleotide sequence that is complementary to the matching codon on the mRNA molecule.
The correct translation of the genetic code is made possible by this complementary matching, which enables the tRNA to identify and attach to the mRNA codon through base pairing. The exact amino acid that will be incorporated into the expanding polypeptide chain during protein synthesis is determined by the anticodon.
Thus, the ideal selection is option A.
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All of the following are characteristics of benign tumors EXCEPT
A. they do not spread.
B. can sometimes be present as cysts.
C. cannot increase in size.
D. cause problems only when they become large enough to interfere with the normal functioning of neighboring organs.
E. are considered noncancerous.
The reaction-center chlorophyll of photosystem I is known as P700 because
A) there are 700 chlorophyll molecules in the center
B) this pigment isbest at absorbing light with a wavelength of 700 nm.
C) there are 700 photosystem I components to each chloroplast.
D) it absorbs 700 photons per minute
Answer:
The correct answer will be option-B.
Explanation:
Photosystem of a plant is complex pigment-protein molecules which absorbs the light energy required for the formation of a glucose molecule.
Two types of Photosystem are present in the plants which are: P₆₈₀ and P₇₀₀. The 680 and 700 denote the wavelength of the light energy absorbed by the pigment of the chloroplast. The electrons get excited only at their absorbing wavelength.
Thus, Option-B is the correct answer.
The reaction-center chlorophyll of photosystem I, known as P700, is named for its ability to absorb light optimally at a wavelength of 700 nm.
Explanation:The reaction-center chlorophyll of photosystem I is known as P700 because this pigment is best at absorbing light with a wavelength of 700 nm. You can deduce this from the way reaction center chlorophylls in photosystems are named. For example, P680 reaction centers, found in photosystem II, are named for their peak light absorption at 680 nm.
Importantly, the naming does not reflect the number of chlorophyll molecules or photosystem components, nor does it relate to the number of photons absorbed per minute, but it is solely based on the wavelength of light that is most effectively absorbed by the pigment.
A double stranded base-paired structure formed by folding a single strand of DNA or RNA back upon itself.
a. mirrorlike palindrome
b. A-DNA
c. B-DNA
d. hairpin
Answer:
d. hairpin
Explanation:
A double-stranded base-paired structure formed by folding a single strand of DNA or RNA back upon itself like a hairpin. Base pairs are the unit of nitrogenous bases which are joined together by hydrogen bonds. They synthesize the double helix model which contribute the folded structure of both RNA and DNA. Sugar and phosphate is the backbone of DNA. DNA has four nitrogenous bases named adenine, thymine, guanine, and cytosine.
Complete the following statements using as many of the following terms as are appropriate: mitosis, meiosis I (first meiotic division), meiosis Il (second meiotic division), and none (not mitosis nor meiosis I nor meiosis Il). a. The spindle apparatus is present in cells undergoing_____ b. Chromosome replication occurs just prior to_____ c. The cells resulting from____ in a haploid cell have a ploidy of n. (d). The cells resulting from____ in a diploid cell have a ploidy of n. (e). Homologous chromosome pairing regularly occurs during_____ (f). Non-homologous chromosome pairing regularly occurs during_____ (g). Physical recombination leading to the production of recombinant progeny classes occurs during____ (h). Centromere division occurs during_____ (i). Non-sister chromatids are found in the same cell during
Mitosis is responsible for cell division, meiosis I reduces ploidy level, crossing over and chromosome recombination occur in meiosis I, and non-sister chromatids are found in the same cell during meiosis I.
Explanation:a. The spindle apparatus is present in cells undergoing mitosis.
b. Chromosome replication occurs just prior to meiosis I.
c. The cells resulting from meiosis I in a haploid cell have a ploidy of n. (d). The cells resulting from meiosis II in a diploid cell have a ploidy of n.
e. Homologous chromosome pairing regularly occurs during meiosis I.
f. Non-homologous chromosome pairing regularly occurs during meiosis II.
g. Physical recombination leading to the production of recombinant progeny classes occurs during meiosis I.
h. Centromere division occurs during meiosis II.
i. Non-sister chromatids are found in the same cell during meiosis I.
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Plastids that are surrounded by more than two membranes are evidence of
a. evolution from mitochondria.
b. fusion of plastids.
c. origin of the plastids from archaea.
d. secondary endosymbiosis.
Answer:
d. secondary endosymbiosis.
Explanation:
When a living cell acquires another organism that eventually becomes a part of this cell, this process is known as primary endosymbiosis.When an organism that has already undergone primary endosymbiosis engulfs another eukaryotic organism then this process is known as secondary endosymbiosis. Secondary endosymbiosis has been known to occur in plastids because of which they are surrounded by two membranes. This bilayer is present because one of the layers is the original outer membrane of the organism and the other membrane is that of the organism that has been engulfed.Rods are light sensitive cells of the retina that provide information about color to the brain.
a. True
b. False
Answer:
The correct answer will be option-false.
Explanation:
The eye contains a layer of photoreceptor cells at the back of the eye called retina. The retina contains two types of photoreceptor cells called Cones and rods.
The rod cells contain only one types of pigment and are very sensitive to light and dark changes but cones contains three types of photoreceptors which are sensitive to red, blue and green color.
The cone cell sends signals to the brain about these colors where the brain perceives and produce an image.
Thus, option- false is the correct answer.
Why would a geneticist study a yeast cell or a fruit fly or a mouse in order to understand human genes and human biology?
Answer:
Due to common origin and similarity of genes.
Explanation:
Fruit fly and yeasts are common model organisms that are used by scientists to understand universal biochemical pathways.The universal biochemical pathways exist across different organisms because they share a common origin and have similar genes. The existence of similar genes helps the scientists to manipulate these model organisms such as yeast and fruit fly in the laboratory to understand human genes and human biology as it is ethically prohibited to perform experiments on humans, however, the same can be done on the mouse, fruit fly and yeast cell. Humans share 44 % of their genes with the fruit fly, 26% with yeast cell and 92% with a mouse.Final answer:
Geneticists study model organisms like yeast cells, fruit flies, and mice because they share significant genetic and biological characteristics with humans, making them practical and efficient for genetics research. These organisms facilitate the understanding of human genes and can be easily modified and cultured, allowing for more rapid scientific progress.
Explanation:
A geneticist would study organisms like yeast, fruit flies, and mice to understand human genes and biology because these organisms, known as model organisms, share many genetic and biological similarities with humans. Fundamentally, yeast cells (Saccharomyces cerevisiae) as eukaryotic organisms, produce and modify proteins in a way comparable to human cells, making them valuable for recombinant DNA technology experiments. Similarly, the fruit fly (Drosophila melanogaster) and the house mouse (Mus musculus) have been used extensively in genetic research because they have well-sequenced genomes and exhibit biological processes analogous to those in humans, such as metabolizing alcohol.
Fruit flies are particularly important because they are able to metabolize alcohol like humans, providing insights into genes affecting sensitivity to alcohol. This research holds the promise of understanding and potentially addressing variations in alcohol sensitivity in humans. Additionally, model organisms are generally easier to study due to their simpler structure, shorter generation times, and the ease with which they can be genetically modified.
How would DNA extracted from an onion be different from the DNA extracted from cauliflower? Why?
Answer:
Explanation:
DNA extration from a onion and from a cauliflower would be different because even though all DNA is composed by the same nucleotides. The sequence of genes will be different in both onion and cauliflower. That's why a cauliflower doesn't look like a onion. The genes are responsible for making up the cauliflower and the onion.
Which of the following vectors holds the largest pieces of DNA?
a. plasmids
b. bacteriophage
c. YACs
d. PACs
e. cosmids
Answer:
c. YACs
Explanation:
YACs, the Yeast artificial chromosomes are the high capacity vectors designed to carry the eukaryotic genes and carry the insert of 200-2000 kb.
YACs carry origin of replication from yeast, selectable markers and sequences derived from telomeres and centromere to maintain the stability of the insert during cell division.
The insert size for plasmids, bacteriophage, PACs, and cosmids is about 0.1-10 kb, 5-25 kb, 100-300 kb, 35-45 kb respectively.
Carbon fixation occurs when CO2 combines with:
a. RuBisCo
b. G3P
c. RuBP
d. Glucose Phosphate
Answer:
The correct answer will be option-C.
Explanation:
Carbon fixation is a step of the light-independent reaction called the Calvin cycle of the photosynthesis. The Calvin cycle proceeds in three steps: carboxylation, reduction and regeneration of RuBP.
During carboxylation, the carbon from carbon dioxide binds the RuBP molecule, a five-carbon molecule by Rubisco enzyme and form two molecules of 3-phosphoglycerate (3PGA).
Thus, Option-C is the correct answer.
Carbon fixation results from the combination of CO₂ and RuBP, catalyzed by the enzyme RuBisCo. The correct answer is 'c. RuBP'. The other options listed are also parts of the photosynthesis process
Explanation:Carbon fixation is an important process in photosynthesis where the atmospheric carbon dioxide (CO₂) is converted into organic compounds. In this process, CO₂ combines with Ribulose-1,5-bisphosphate (RuBP). This process is catalyzed by the enzyme named Ribulose-1,5-bisphosphate carboxylase/oxygenase, commonly known as RuBisCo. Option 'c. RuBP' Is the correct answer in this context.
It's important to note that the other options in your question are part of the photosynthesis process as well. G3P (Glyceraldehyde-3-phosphate) is the molecule that is created as a result of the carbon fixation process, while glucose phosphate is part of the process of converting G3P to glucose.
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Explain in a concise manner:
(a) Factors affecting fermentation
(b) Types of fermentations
(c) Industrial uses of fermentation
(d) Isolation of microorganisms
(e) Component parts of fermentation
Answer:
Explanation:
A) Factors affecting fermentation
Factors which influence the rate of fermentation are as follows-
1) Nutritional requirements-
The media plays a crucial role in the process. Adequate amount of nutrients like C, N , K , P, O2 etc are necessary for the growth and metabolic activity of the microorganisms.
2) Temperature- Optimum temperature is required for the apt growth of the biomass.
3) pH of the fermentation process -Microorganisms grow, multiply and produce active proteins in adequate physio-friendly environment.
4) Mechanical process and Oxygen Transfer- Agitation
The agitation in the reactor allows enough mixing and oxygen transfer which enhances the morphology of the microorganisms.
B) Types of Fermentation
1) Batch type fermentation- The necessary nutrients required are added before inoculation. It is a discontinuous process
2) Fed batch fermentation- Initial medium concentration is low.
3) Continuous fermentation- Fresh media is continuously added to the reactor
4) Solid state fermentation- It is the growth of microorganisms on solid material in the absence of water.
5) Anaerobic fermentation- In the presence of oxygen
6) Aerobic fermentation- in the absence of oxygen
C) Industrial uses of fermentation
Fermentation has multiple uses in various sectors like
1)Agriculture- Plant growth hormones
2)Industrial Fermentation- Enzyme production, antibiotic production, ethanol production etc.
3)Agro-food industry- Food additives
D) Isolation of microorganisms
Isolation is the separation of microorganisms from each other in a mixed culture.
Few techniques employed to isolate the culture are- Streaking, Plating, Dilution, Enriched Procedure and Single cell technique.
E) Components parts of fermentation
There are three parts of a fermentation process namely
-Upstream processes: Primary screening, preparation of pure culture and selection of production strain at lab scale level
-Production processes: Continuous monitoring the production process to maintain best possible conditions for maximum product formation
-Downstream processes:The extraction of the product and its purification and the disposal of effluents produced by the process.
The tissues are higher organisation level than ___________
a. organism
b. cells
c. organ systems
d. organs
Answer:
Cells
Explanation:
Cells are the structural and functional unit of life. Tissues are a group of closely associated similar cells. These groups of cells work together to perform a specific function.
Organs are made of many related tissues while various related organs together make the organ systems.
For example, epithelial tissues are the group of cells that line the body cavities and serve in the protection of body surfaces and internal organs.