Answer:
b. False
Explanation:
As GPP stands for the gross primary productivity, it's the total amount of energy produced in the process and the NPP is the net primary productivity. NPP is the difference between the GPP and the energy used by the producer for the process of respiration. GPP is a continuous and ongoing process that consumes the energy as compared to the NPP that store energy and not being used. Thus, GPP can affect NPP but NPP does not affect GPP. For example, GPP is completely being dependent on the chlorophyll content of the plant, but NPP is independent of that content of chlorophyll.Abiogenesis refers to how living organisms arose from inanimate matter. Place the sentences in order according to how life on Earth may have arisen from terrestrial origins. Only four sentences will be used.
(A) Precursors Simple inorganic compounds were exposed to energy in the form of light, heat, and lightning
(B) Larger organic molecules became enclosed within a membrane-like structure
(C) Organic molecules self-assembled into more complex molecules and polymers.
(D) Simple organic molecules, such as amino acids, formed from precursors exposed to energy
(E) Meteorites that impacted Earth-4 billion years ago contained traces of 18 amino acids.
Answer:
(A) -> (D) -> (C) -> (B)
Explanation:
First off, given that the problem requires us to explain how life on Earth may have arisen from terrestrial origins, we can discard sentence (E), as impacts from meteorites would count as extraterrestrial origins.
Then it's just a matter of describing the steps by which simple compounds turned into more and more complex structures, that would in turn lead to the origin of life.
Simple inorganic compounds (such as CO₂, or NH₃) were exposed to energy, because of that they formed simple organic molecules, like carbohydrates or amino acids.
These organic molecules, in turn, would self-assemble into more complex structures, such as proteins.
Lastly, there's the phenomenon of Compartmentalization, where large organic structures became enclosed within a membrane-like structure, separating them from the 'outside' medium and thus creating primitive cells.
What feature is unique to Yersinia pestis when compared to other Yersinia species?
A- Motile
B- Capsule
C- Spore forming
D- Can grow in the presence of oxygen
Answer:
B-Capsule
Explanation:
Bacteria from Yersinia genus don't develop capsules, but Yersinia pestis has the exception. Y.pestis develops a similar structure to a capsule.
Other options are true for Y.pestis and all Yersina genus. Despite the fact that someones can lose their motility in a stage of their life cycle, these bacteria are motile. Also, they are facultative anaerobic organisms and they don´t form spores.
Describe the chemical components of DNA.
DNA is composed of nucleotides, which are composed of three parts:
1. A five carbon carbohydrate (pentose)
Pentose is classified as a monosaccharide (simple carbohydrate), and its molecular formula is represented by [tex](CH_{2} O)n[/tex]. They are water soluble molecules with sweet taste. Monosaccharides may have from three carbon atoms (trioses) to six (hexoses). In DNA is present pentose (5 carbon atoms)
2. A nitrogenous base
Nitrogenous bases are ring-shaped compounds that contain nitrogen in their molecular structure. They are classified into two groups: purines and pyrimidines
The purine bases are adenine (A) and guanine (G). They are larger and contain more than one ring in their structure,.
The pyrimidines, cytosine (C), uracil (U) and thymine (T), are smaller and composed of a single ring.
3. One or more phosphate groups
A phosphate consists of a trivalent anion that contains one phosphorus atom and four oxygen atoms. Its molecular formula is expressed by [tex](PO_{4} ^{-3})[/tex].
The chemical components of DNA are nucleotides, made up of deoxyribose sugar, phosphate group, and four nitrogenous bases. These components form the structure and base pairs in DNA molecules.
Explanation:The Chemical Components of DNA
The chemical components of DNA are nucleotides, which are made up of a sugar molecule called deoxyribose, a phosphate group, and one of four nitrogenous bases: adenine (A), thymine (T), cytosine (C), or guanine (G). The sugar and phosphate group form the backbone of the DNA molecule, while the nitrogenous bases pair up to form the rungs, or base pairs, of the DNA ladder.
Example:
A DNA molecule may have the sequence ATCGAT.
In this example, the sugar deoxyribose and phosphate group (sugar-phosphate backbone) connect the nucleotides, while the nitrogenous bases A, T, C, and G pair up in a complementary way: A pairs with T, and C pairs with G.
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Which of the following is not a characteristic of cancer cells?
A. They have a coarse chromatin.
B. They have a single small nucleus.
C. They have multiple nuclei.
D. They have a small amount of cytoplasm.
E. They have large and multiple nucleoli.
Answer:
B. They have a single small nucleus.
Explanation:
The presence of large nucleus is a characteristic feature of cells that frequently undergo cell division. Cancer cells are characterized by uncontrolled continuous cell division even when the new cells are not required by the body.
This leads to the formation of benign or metastatic tumors. To undergo continuous cell division, the cancer cells have a large nucleus. The nucleus of the cancer cells is mostly hyperchromatic and distinct due to higher nuclear to cytoplasmic ratio. It allows these cells to exhibit the uncontrolled cell division.
To apply parsimony to constructing a phylogenetic tree,
a. choose the tree that assumes all evolutionary changes are equally probable.
b. choose the tree in which the branch points are based on as many shared derived characters as possible.
c. choose the tree that represents the fewest evolutionary changes, in either DNA sequences or morphology.
d. choose the tree with the fewest branch points
Answer: d. choose the tree with the fewest branch points
Explanation:
Parsimony is a phenomena of evolution which involves classifying organisms on the basis of their characteristic under levels. The most parsimonious tree is a tree, which depends upon morphological characters with few evolutionary events. So, while constructing a phylogenetic tree based on parsimony, the tree, which has few evolutionary lineages in terms of both DNA base pairing as well as in the morphology, can be taken into consideration.
Hence, the correct option is (d).
To apply parsimony to constructing a phylogenetic tree choose the tree that represents the fewest evolutionary changes, in either DNA sequences or morphology. Option C is correct.
Parsimony is the cornerstone of all science and implies that the simplest possible scientific explanation is the one that best fits the evidence.
When it comes to tree-building, it implies that all else being equal, the simplest possible hypothesis is the hypothesis that requires the least evolutionary change.
Maximum parsimony (MPS) is a fundamental way of identifying evolutionary relationships between species based on the minimum number of changes that may have led to the current phenotypic characteristics.
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Which statements describe molecules? Check all that apply. Molecules are made of two or more atoms. Molecules are all the same size Molecules range in size. Molecules are only made of atoms of the same element. Molecules are only made of atoms of different elements. Molecules are made of atoms of the same element or different elements
Molecules are composed of two or more atoms, which can be the same or different elements, and they vary significantly in size from simple to complex structures like DNA.
To describe molecules, several statements are necessary. Firstly, molecules are made of two or more atoms; this is a fundamental component of their definition. Whether they are composed of the same element or different elements, the atoms are bound together chemically.
As an important distinction, molecules of elements contain only one type of atom, such as O2, which has two oxygen atoms, whereas molecules of compounds contain two or more types of atoms, like H2O, which includes hydrogen and oxygen.
Next, molecules range in size. They can be relatively simple with just a few atoms, or they can be incredibly complex, such as DNA molecules, which are composed of millions of atoms. Lastly, it is incorrect to say that molecules are all the same size or that they are made only of atoms of the same element or only of different elements.
An albino corn snake is crossed with a normal-colored corn snake. The offspring are all normal-colored. When these first- generation progeny snakes are crossed among themselves, they produce 32 normal-colored snakes and 10 albino snakes. a. How do you know that only a single gene is responsible for the color differences between these snakes? b. Which of these phenotypes is controlled by the dominant allele? c. A normal-colored female snake is involved in a test-cross. This cross produces 10 normal-colored and 11 albino offspring. What are the genotypes of the parents and the offspring?
a. We can infer that only one gene is responsible for the only two phenotypes of snakes due to the 3: 1 Mendelian ratio. If there were other genes involved, the ratio would be different.
b. The normal-colored
c. To have raised an albino half offspring, these individuals received a recessive gene from both father and mother. And the other half of normal individuals received at least one dominant gene. Since the statement says that the female snake is a normal phenotype, we know that it has a dominant and a recessive gene. The male snake can only be recessive homozygous to generate offspring half and half. If he was heterozygous for the disease, the offspring would have a 3: 1 ratio.
Here you can see the cross and the genotype of each individual:
A x a
a Aa aa
a Aa aa
Mammalian evolution began with the evolution of the first synapsids. What is the defining synapomorphy of synapsis?
a. the possession of the amniotic egg
b. a single temporal fenestra
c. the dentary squamosal joint
d. respiration with a diaphragm
e. endothermic metabolism
Answer:
b. a single temporal fenestra
Explanation:
Synapsids have a temporary fossa in the lower part of the temporal bone. These reptiles mamiferoides only have a single inferior temporal fenestra.
The synapsids were the first amniots to diversify and appeared in the middle of the Carboniferous. These first synapses were characterized by the presence of a single temporary fenestra behind each orbit, through which the mandibular muscles pass.
In the first step of spermatogenesis, spermatogonia differentiate cells into
A. Spermatids
B. Primary spermatocytes
C. Secondary spermatocytes
D. Spermatozoa
E. Spermatophyte
Answer:
B. Primary spermatocytes
Explanation:
The germ cell line is a group of cells found inside the seminiferous tubules. This germ cells undergo mitosis (creating spermatogonia) to have a steady supply of cells that will divide by meiosis to produce gametes. When spermatogonia divide by meiosis at the end of meiosis I the newly created cells are known as primary spermatocytes.
Which of the following are useful traits of cloning vectors?
a. an antibitioc resistance gene on the plasmid for selection of cells containing the plasmid
b. a site that contains unique, clustered restriction enzyme sequences for cloning foreign DNA
c. a high copy number plasmid so that large amounts of DNA can be obtained
d. alpha complementation to determine if the foreign DNA was inserted into the cloning site
e. all of the above are useful traits
Answer:
The correct answer is option - e. all of the above are useful traits.
Explanation:
A cloning vector is a small segment of DNA that can be established stably in an individual organism and able to internalize a foreign DNA for cloning purposes. The cloning vector could be taken from different organisms such as plasmid of a bacterium, or DNA from a virus. A cloning vector must possess some characteristics -
The cloning vector must be self-replicating ability in the host cells, it should be small in size with restriction site for the restriction endonuclease enzymes in it. The replication character of the vector should not interfere with the internalized DNA fragment. The presence of marker genes in the vector is also a property that is helpful in identifying of recombinant cells.
Thus, the correct answer is option - e. all of the above are useful traits.
Why do we need respiration?
Answer:
When we breath, we are making respiration. As me are doing respiration, a lot of glucose (we get from food) is turning into ATP, and that is energy; the energy to make cells function. That's why respiration, is important.
Explanation:
Glucose (food) + Oxigen (breathing) ---> carbon dioxide (free by lungs) + water + ATP
Answer:
to inhale oxygen and exhale carbon dioxide (cellular respiration)
Explanation:
Glucose (food) + Oxygen (breathing) ---> carbon dioxide (free by lungs) + water + ATP
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 4.70×106 base pairs. Determine the number of codons that can be present in this DNA molecule
Answer:
1.6x[tex]10^{6}[/tex]
Explanation:
All you have to do is divide the number of base pairs by 3, since 3 nucleotides constitute a codon.
Ultimately, the oxygen necessary for cellular respiration come from
a. Waste products of photosynthesis.
b. Water vapor
c. Carbon dioxide
d. glucose
Answer: Option A
Explanation:
Plants intake the carbon dioxide that is present in the atmosphere. They absorb it and along with water and other materials in the presence of sunlight is converted into chemical energy.
This chemical energy is glucose and the by-product that is released by splitting of water into oxygen and hydrogen ions is released into the environment.
This oxygen is required for the process of cellular respiration.
What do structures B and C have in common?
Both B and C epresent the muscularis externa, the outermost layer of smooth muscle found in most hollow organs of the digestive tract. This layer contracts and relaxes to propel food along the digestive system.
: B and C are major blood vessels supplying the respective sections of the digestive tract. Adequate blood flow is crucial for nutrient absorption and transport. They could also represent lymphatic vessels involved in draining fluids and immune cells from the digestive tract. The lymphatic system plays a vital role in fighting infection and absorbing dietary fats.
B and C could be labeled as nerves or ganglia, representing the autonomic nervous system branches controlling digestive functions like muscle movement and secretion of digestive juices.
Where does the energy in food come from?
A. Proteins, carbohydrates, or fats
B. ATP
C. Food, by itself, doesn't contain energy, but the digestive system creates it.
D. The chemical bonds holding the food molecules together
E. Combining water with any sort of food creates energy.
Answer:
A. Proteins, Carbohydrates, or fats
Explanation:
There are essential nutrients for life in which we can include carbohydrates, fats, proteins, minerals, vitamins, fiber, and water. The main nutrients we use for energy are carbohydrates, fats, and proteins. This is because they contain calories in them and the calories are what our body needs to create energy.
Our bodies, like a car, need fuel to function. The fuel we need comes from food. The food has energy stored in it so whenever we eat food, that stored energy is transferred to us. This food act as fuel for the cells in our body so they can carry all the metabolic processes and give us the energy to move, run, think, talk, digest and all of the biological processes we need to survive.
Q:- In dogs, the Mexican hairless phenotype never breeds true. When Mexican hairless are interbred the offspring are 2/3 hairless and 1/3 normal. It is also observed that some deformed puppies are born dead. Propose a genetic explanation for these observatios.
Explanation:
The problem says that the hairless phenotype never breeds true. That means that it's not the result of a homozygous genotype (H₁H₁ or H₂H₂), so it is caused by the heterozygous genotype (H₁H₂).
The expected offspring from the cross between two Mexican hairless would be:
P H₁H₂ x H₁H₂F1 1/4 H₁H₁, 2/4 H₁H₂ and 1/4 H₂H₂.And the expected phenotypic ratio 3:1. However, the observed offspring shows a 2:1 ratio. What's happening?
If the observed phenotypic ratio in the offspring of a monohybrid cross (a single gene with two alleles) is 2:1, we can suspect that one of the genotypes is lethal in homozygosis and therefore does not appear in the progeny (the puppies are born dead).
If we proposed that the H₂ allele is lethal in homozygosis, then:
The H₁H₁ genotype would cause normal puppies --> 1The H₁H₂ genotype would cause hairless puppies --> 2The H₂H₂ is lethal and causes the death of puppies --> 0The phenotypic ratios change to 2:1, as observed in the experiment.
Which cell would be best for studying lysosomes?
(A) muscle cell
(B) nerve cell
(C) bacterial cell
(D) phagocytic white blood cell
Answer:
(D) phagocytic white blood cell
Explanation:
Lysosomes are cell organelles which contain hydrolytic or digestive enzymes. They engulf waste materials, dead cells, and microorganisms. They break them down them using digestive enzymes. Muscle cell, nerve cell s do not perform phagocytic or lysosomal activities and the bacterial cell is a prokaryotic cell which does not contain lysosomes. Therefore, white blood cells are phagocytic contains lysosomes. Due to the presence of lysosomes, white blood cells or leucocytes protect our body from infectious diseases.
Answer:
(D) phagocytic white blood cell is the correct answer.
Explanation:
phagocytic white blood cell is best for studying lysosomes.
lysosomes are the cell organelles, its function is to digest the dead cells, bacteria and waste substance with help enzymes such as lipases, amylases, and proteases.
Phagocytic white blood cells are best for studying lysosomes because many white blood cells are found in lysosomes.
White blood cells function is to ingest or engulf the foreign materials and protect the body from the infection.
What is the relationsihp betwen biotic and abiotic factors AND evolution?
Explanation:
The abiotic factor are the ice age , meteor , chemicals , never hinder or help the evolution or development of the biotic factors .
As , the ice age can resists or slow down the growth of many of the tropical plants and animals .
But it facilitates the evolution of the organism that can get adapted to the cold climate .
A large amount of oxygen in the environment which is produced by the cyno bacteria helps the evolution of the animals .
Food irradiation requires a nuclear reactor, which produces radioactive waste.
a. True
b. False
Answer:
b. False
Explanation:
Food irradiation is a process of exposing the food packaging stuff to the ionization process by the use of X Rays, gamma rays, and electronic beans. This energy can be directly transmitted without the direct contact of the source i.e radiation capable of freeing the elections. This technology is used to improve food quality and safety by extending the shelf line. This technology is permitted to bout 50 countries with 5 lakh metric tons of foods manually processed. These techniques make the food more productive and reduce the impact of radioactivity and chemical reactions. Destruction of pathogens and changes that take place in shipping industries. The radiation cause changes are much higher than the doses used during irradiation these results lead to the conclusion that there is no significant risk from radiolytic products.What kind of sequence or structure would you classify this as
CGACCAGC
GCTGGTCG
Question options:
a. inverted repeat
b. mirrorlike palindrome
c. hairpin
d. stem and loop motif
Answer:
The correct answer will be option-A.
Explanation:
Inverted repeats are the sequence of the nucleotide in a nucleic acid which is identical but arranged in the opposite orientation. The inverted repeat may be separated by some sequence or they may lie adjacent to each other. They can be read the same from the backwards or forward direction.
In the given question since four bases when read from the forward direction is same as reading the sequence from the backward direction like CGAC can be read the same both backward and forward.
Thus, option-A is the correct answer.
The circulatory system delivers oxygen and nutrients to the cells and transports wastes away from cells.
a. True
b. False
Answer:
True.
Explanation:
Circulatory system may be defined as the network of the various blood vessels that helps in the transportation of materials inside the body. Circulatory system is also known as cardiovascular system.
The main function of the circulatory system is to delivers the oxygen to each and every cell of the body. The nutrients are transported into the cells via blood and waste materials are transported away from the body. This system is also important to provide immunity to the body.
Thus, the correct answer is option (a).
In a particular population of mice, certain individuals display a phenotype called "short tail," which is inherited as a dominant trait. Some individuals display a recessive trait called "dilute," which affects coat color. Which of these traits would be easier to eliminate from the population by selective breeding? Why?
Answer:
The "short tail" dominant allele is easier to eliminate by selective breeding.
Explanation:
The only way for a recessive allele to be expressed (be visible) is when it appears as recessive homozygotic. These means the organisms need to have 2 copies of the gene. Selective breeding is based on the characteristics that one can see, so if the organism shows the "dilute" phenotype you can keep reproducing this individuals and get rid of the dominant allele.
On the other hand if you have a population with the dominant phenotype, you discard all the ones that have a recessive trait and you breed the dominant phenotype you could still get individuals with the recessive phenotype and individuals that express the dominant phenotype but are heterozygous.
Nitrogen and carbon are more abundant in proteins than sulfur. Why did Hershey and Chase use radioactive sulfur instead of nitrogen and carbon to label the protein portion of their bacteriophages in their experiments to determine whether parental protein or parental DNA is necessary for progeny phage production?
Answer:
Hershey and Chase experiment confirms that DNA is the genetic material of the living organism, not the RNA or protein. They also got a noble prize for this discovery.
Hershey and Chase use the radioactive sulfur to label the proteins and distinguish them from the DNA because DNA do not contain sulfur. The radioactive label phosphorus was used to label the DNA as phosphorus is specific to DNA as they wants to know exactly the genetic material. They do not use the radioactive carbon and nitrogen because both carbon and nitrogen are present in DNA and RNA. This labeling may produce confused result as it label both DNA as well as protein. The result o radioactive phosphorus and sulfur determines that DNA is the genetic material of the organism.
Radioactive sulfur and phosphorus were used to distinctly label T2 bacteriophage proteins and DNA, leading to the discovery that DNA is the genetic material in Chase and Hershey's 1952 experiments.
Explanation:In the groundbreaking Hershey-Chase experiments, radioactive sulfur (³⁵S) and radioactive phosphorus (³²P) were used to label proteins and DNA, respectively, in T2 bacteriophages. They chose radioactive sulfur to label the protein because sulfur is present in some amino acids (methionine and cysteine) that comprise proteins, but is not a component of nucleic acids.
Conversely, they used radioactive phosphorus to label the DNA because phosphorus is a key component of the DNA molecule but is not found in the amino acid structure of proteins. The conclusive experiment demonstrated that radioactivity from the labeled DNA, not the protein, was present inside the bacterial cells infected by the phages, thereby identifying DNA as the genetic material responsible for inheritance.
emochromatosis is an inherited disease caused by a recessive allele. If a woman and her husband, who are both carriers, have three children, what is the probability of each of the following?
(a) All three children are of normal phenotype.
(b) One or more of the three children have the disease.
(c) All three children have the disease.
(d) At least one child is phenotypically normal.
Answer:
(d) At least one child is phenotypically normal.
Explanation:
To be a carrier means that you have the gen but you are not affected by it.
If both parents have that recessive gene, this means, both are heterozygous for that trait.
Let's say this gen is A, for the dominant trait, and "a" if it's recessive.
The mother and the father are Aa.
If you cross them you have Aa x Aa = AA Aa aA aa
This means you have 50% of Aa, carrier children
25% AA, not a carrier or affected by this gen.
25% aa, affected by the gen.
At the beginning of the Cenozoic, the distribution of continents changed from that seen throughout most of the Mesozoic. Which of these best describes the new distribution of continents?
a. a single land mass that allowed for easy moevement of animals between continents
b. individual land masses that are moving towards the poles
c. most of the land masses are located near the equator
d. the continents were already in the positions that we have in the current time.
Answer:
b. individual land masses that are moving towards the poles
Explanation:
The Mesozoic started with the Triassic period, 251.9 million years ago, after a mass extinction that wiped out most of life on Earth. At this moment, all the continents were part of a continuous landmass called Pangaea. By the Late Jurassic, the continents started to drift towards the poles. Africa and South America stay move from the southern hemisfere towards the Equator, Antartica and Australia move towards the south pole. It is during this time that we have two continents: Laurasia in the north, comprised of Europe, North America, Russia, China, and parts of Central Asia; and Gondwana, comprised of South America, Africa, Australia, India and Antarctica.
Towards the end of the Mesozoic, Laurasia and Gondwana also start to split. Laurasia breaks up and still occupies the Northern hemisphere, but pieces of broken Gondwana drifted north, such as South America, Africa and India. Of these, Africa collided with Europe and originated the Italian peninsula, the Iberian peninsula, and the Balkan region. The collision of India with China, Tibet and Russia prompted the beginning of the formation of the Himalaya.
By the beginning of the Cenozoic, Laurasia and Gondwana had split into several individual landmasses, most of them in the Northern Hemisphere.
Distinguish the different structural forms of DNA from one another.
Answer:
The major structural forms of DNA are A- DNA, B-DNA, and Z-DNA.
There are several differences among the 3 DNAs in their helix turn, number of nucleotides, distance between the base pairs, etc.
Explanation:
DNA is a double-stranded helix. These are the twisted ladders where base pairs are attached by hydrogen bonds. There are 3 major forms of DNA such as A - DNA, B- DNA, and Z - DNA. They are different from each other by their helix type, diameter or complete turn, and distance between the 2 base pairs.
A - DNA: This type of DNA was discovered by Rosalind Franklin. It was discovered by the X-ray diffraction method. Its helixes are right-handed. The helixes are shorter than the B - DNA. The diameter of the helix is 2.55nm. The distance between the base pair/rise is 0.29nm. The number of base pairs per complete turn is 11.
B - DNA: This is the common type of DNA structure. This is the Watson and Crick model of DNA. The helix is right-handed and the diameter is 2.37nm. The distance of a complete turn is 3.4nm. The rise per base pair or the distance between 2 base pairs in B-DNA is 0.34nm. The number of base pairs per complete turn of the helix is 10 nucleotides.
Z -DNA: It is the left-handed DNA. This type of DNA was discovered by Robert Wells and colleagues. This DNA is in a zig-zag form. So it is called Z-DNA. It is long and thin than other DNA. The distance per turn is 4.5 nm. and rise per base pair is 0.37 nm. The number of base pairs per complete turn is 12 nucleotides. The minor groove is deep.
If the B-DNA is compressed it becomes the A-DNA and if the B-DNA is expanded it turns into a Z- DNA.
The theory of heredity before Mendel's work was completed can be described as:
a. the theory of chromosomal transmission
b. the theory of blending inheritance
c. the theory of particulate inheritance
d. the theory of natural selection
e. none of the above describes the view of heredity before Mendel's time
Answer:
b. the theory of blending inheritance
Explanation:
Before Mendel's work was completed and published, theory of blending inheritance was widely accepted. According to it traits from both parents were blended and expressed in the next progeny. The new trait wont be in extreme like its parents' and would fall somewhere in between the spectrum.
Mendel disproved theory of blending inheritance by his famous pea experiment. When he crossed a pure breeding tall and pure breeding dwarf pea plant he got all tall pea plants in next progeny. According to theory of blending inheritance, the height of pea plants in next progeny should have been a result of mixing of heights from the two parent plants. But all the plants were tall like one of the parent plant disapproving the theory.
Answer:
The correct answer will be option-E.
Explanation:
Gregor Mendel is known for his transmission of traits- the principle of inheritance.
He was the first person to show the idea that how the traits are passed on from generation to the next generation through factors which gave rise to the theory of heredity.
Before him, no other theories wee predicted and proposed to show the inheritance pattern and therefore option-E is the correct answer.
Explain why the value of the recombination frequency between any two genes is limited to 50%.
Answer:
Explanation:
During meiosis, each chromosome has 2 chromatids. When homologous chromosomes pair they form a tetrad (2 chromosomes, 4 chromatids).
Crossing over can happen between 2 out of the 4 chromatids, and as a result, only half of the resulting gametes (at most) can be recombinant. The other 2 gametes will be parental.
What is considered the fundamental unit of life?
A. DNA
B. Carbohydrates
C. A molecule
D. Nucleic acid
E. A cell
The correct answer is E. A cell
Explanation:
The cell is the smallest unit of life that exists and that constitutes all living organisms and body tissues including unicellular and multicellular organisms. Due to this, cells are considered as the fundamental unit of life as even the smallest and simplest living organisms are made of cells or at least made of one cell.
Cells are commonly made up of three main parts: the cell membrane which surrounds the cell and controls the substances that enter and leave it; the nucleus which is the structure within the cell that contains the nucleolus and most of the cell's DNA; and the cytoplasm that is the fluid inside the cell that contains other tiny cell particles with specific functions, such as the Golgi apparatus, mitochondria, and the endoplasmic reticulum. This applies to all cells except to prokaryotic cells because these do not contain a nucleus but a chromosome in the middle of the cell.
People can get smallpox from the smallpox vaccine.
a. True
b. False
Answer:
FALSE
Explanation:
Smallpox was a highly contagious viral disease characterized by the high fever, skin rash, sores in mouth and vomiting. This infection was caused by the virus Variola minor and Variola major.
Smallpox vaccine developed by the English physician and scientist, Edward Jenner in 1796, was the first successful vaccine for smallpox.
In 1980, this infection was certified as globally eradicated.