Answer:
The answer is the accessory nerve.
Explanation:
We have 12 pairs of cranial nerves, the accessory nerve is the XI pair. This is responsible for the innervation of the sternocleidomastoid and trapezius muscles.
The fibers of the accessory nerve originate from neurons that are located in the upper spinal cord. These fibers join together forming roots and once the nerve is constituted, it enters the skull through the great hole that is located at the base of the skull.
Then, the nerve continues its path along the inside of the skull in the direction of the jugular hole and then leaves the skull next to the glossopharyngeal nerve (IX) and the vagus (X).
Thus, the accessory nerve enters and leaves the skull again, characterized by being the only cranial nerve which has this behavior.
Answer:
The correct answer is indeed the
accessory nerve
The fibers that make up the accessory nerve enter the skull through the foramen magnum and proceed to exit the jugular foramen with cranial nerves IX and X. Due to its unusual course, the accessory nerve is the only nerve that enters and exits the skull.
Two eukaryotic proteins have one domain in common but are otherwise very different. Which of the following processes is most likely to have contributed to this similarity?
a. gene duplication
b. RNA splicing
c. exon shuffling
d. random point mutations
Answer:
The correct answer is option c. "exon shuffling".
Explanation:
Exon shuffling is a molecular mechanism at which two or more exons from different genes are brought together and results in the formation of new genes. If two eukaryotic genes have one domain in common but are otherwise very different it is very likely that exon shuffling contributed to this similarly. Probably, the exon that encodes for the domain that the two proteins have in common was taken from one protein for the formation of the second one.
Final answer:
The most likely process contributing to the similarity between two eukaryotic proteins with a common domain is exon shuffling, a process of unequal recombination that exchanges exons between genes, resulting in a gene with an additional exon and potentially new protein functions. Thus, option C is correct.
Explanation:
When two eukaryotic proteins share a common domain but are otherwise different, the most likely process that contributed to this similarity is exon shuffling. Exon shuffling occurs through unequal recombination events that allow for the exchange of exons, which are segments of DNA that encode for protein domains. Such recombination can result in a gene acquiring an additional exon from another gene, potentially leading to a protein with a new domain and function while still retaining other original functions. Since introns, which are non-coding regions of DNA, tend to be larger targets for mutations, they can act as a buffer, allowing exons to be shuffled without necessarily disrupting existing coding sequences. Thus, proteins from different evolutionary paths can have common structural features due to the movement and recombination of these exons.
Gene duplication alongside exon shuffling can also contribute to this phenomenon. Gene duplication allows for one copy of a gene to acquire new functions through mutation while the other retains its original function, further increasing species diversity. This combination of processes facilitates the rapid evolution of new proteins using pre-existing domains derived from other genes.
. Suppose that the CO2 concentration in theatmosphere
increased 100-fold. How would this affect the ability ofHb to
deliver O2 and why?
Answer:
Ability to deliver [tex]O_2[/tex] increases.
Explanation:
Carbon dioxide is transported by the blood in the dissolved form. carbonic anhydrase is the enzyme which is a metalloenzyme having zinc at active site converts carbon dioxide into carbonic acid which dissolves in the blood.
Thus,
H₂O (l) + CO₂ (g) ⇔ H⁺(aq) + HCO₃²⁻(aq)
If the concentration of the carbon dioxide is increases, then there is increase in the concentration of the hydrogen ions and thus decrease in the pH which results in the hemoglobin proteins releasing the uptake load of the oxygen. (Bohr effect)
Answer:
dmsasdfsdsa
Explanation:
Genes are ____________
a. amino acids
b. pieces of DNA
c. RNA and sugars
d. strands of RNA
Answer:
b. pieces of DNA is the correct answer.
Explanation:
A gene is a piece of DNA and it is present in the nucleus of all cell's
The function of the gene is to codes for a specific type of protein.
Genes convey the message that determines our characteristics
Genes are called as a functional unit of genetics.
How do human activities have damaged the greenhouse effect?
Answer:
Explanation:
Greenhouse effect is a natural phenomena. The solar radiations from the sun enters the earth atmosphere where some of the sun light is absorbed by the atmosphere as well as the terrestrial land. The rest energy is reflected back to the space. This helps in maintaining the balance of thermal energy on earth. Human activities like burning of fossil fuels, land clearing and agriculture are increasing the amount of greenhouse gases released into the atmosphere. These gases are responsible for absorbing the thermal energy present in the sunlight. Hence, can be responsible for increasing the global temperature worldwide. This is called as greenhouse effect.
What are the major components of the brain? What are the principal functions of each?
Answer:
Human brain is divided into 3 major parts: fore brain, mid brain and hind brain.
Explanation:
Human brain is covered tough tissue called meninges which includes outer dura mater, middle arachnoid membrane and inner pia mater.
Human brain is divided into 3 major parts:
1. Fore brain: it consists of:
a) Olfactory bulb: It receives the impulses pertaining to smell from the olfactory epithelium.
b) Cerebrum: It forms the major part of brain. It is divided into right and left cerebral hemispheres by a longitudinal fissure. It has 3 major functional areas:
i) sensory areas: receive and interpret the sensory impulses
ii) motor areas: controls voluntary muscular movements
iii) association areas: deal with memory and communications
Each cerebral hemisphere is divided into frontal, parietal, temporal and occipital lobes.
c) Diencephalon: Roof of diencephalon is called epithalamus, it is non-nervous part. Lying superior to mid brain is thalamus, which is the coordinating center for the sensory and motor signalling. At the base of thalamus is hypothalamus, which serves as osmoregulatory, thermoregulatory, thirst, hunger and satiety centers.
2. Mid brain: It is located between thalamus of forebrain and pons Varolii of hind brain. It consists of 4 rounded lobes called corpora quadrigemina (4 optic lobes). The two superior colliculi are concerned with visual reflexes and the inferior colliculi are concerned with auditory reflexes.
3. Hind brain: Comprises of cerebellum, pons Varolii and medulla oblongata.
Cerebellum is the little brain, it controls and coordinates the locomotor movements. Pons act as the relay station between cerebellum, spinal cord and rest of the brain. Medulla includes the cardiovascular and respiratory centers, the centers for swallowing, vomiting, coughing, sneezing and hiccupping.
Antiport carrier proteins
a. Allow 2 molecules to be transported in the same direction at the same time
b. Allow 2 molecules to be transported in opposite direction at the same time
c. Allow 1 molecules to be transported
d. Allow 6 molecules to be transported in opposite directions at the same time
Answer:
Option (b).
Explanation:
Carrier proteins allow the movement of the particles inside and outside the cells. Three types of porter are uniport, symport and antiport. These porters transport molecules in the different directions.
The antiporters transport two molecules at a time. These two molecules are transported in the opposite directions at the same time. The one molecule will move inside the cell and the other molecule will move outside the cell.
Thus, the correct answer is option (c).
Explain the bacterial transformation experiments of Avery and his colleagues and the results they obtained.
Answer:
Explanation:
Frederick Griffith performed a different experiment on bacterium streptococcus pneumonia. There are 2 strains of streptococcus i.e. virulent strain i.e. bacteria have a smooth capsule, and the avirulent strain, the bacteria have a rough capsule. Though the smooth live bacteria have virulent strain kills the mouse when it is injected into it. But the rough bacteria did not affect the mouse. When he heat-killed the smoothe bacteria and mix with the rough bacteria it kills the mouse. The single heat-killed smooth bacteria did not kill the mouse. Griffith concluded that there is some transforming principle responsible for making the avirulent bacteria into virulent and this process is called the transformation of bacteria. He failed to show which element transforms from the heat-killed bacteria to rough bacteria.
This experiment was further proceeded by Avery, Macleod, Mccarty. They cultured large quantities of smooth pneumonia cells. The cells are harvested from the culture and heat-killed. Then the heat-killed bacterial cells are homogenized and cell extracts were treated with cell lysates separately. The cell lysates are - DNAse, RNAse, protease, trypsin, lipase.
Then he injected the cell extracts with rough bacteria and put this in Petri dish to form the bacterial colony. They observed each colony show a smooth bacterial colony except the DNAse treated cell. DNAse degrades the DNA and the smooth bacterial colony was not formed. This results, DNA is the element which transforms from the smooth bacteria to rough one and makes it virulent.
Avery and his colleagues finally show DNA is the genetic material.
During pyrosequencing, how are the nucleotides that bind to template DNA identified?
a. pyrophosphate is converted to ADP that binds to the nucleotides to be attached to the template DNA
b. apyrase uses ATP to generate light
c. ATP is broken down by sulfurylase so that luciferin generates light
d. pyrophosphate is converted to luciferin
e. pyrophosphate is converted to ATP so that luciferase is activated.
Answer:
The correct answer is option e. "pyrophosphate is converted to ATP so that luciferase is activated".
Explanation:
Pyrosequencing is a method of DNA sequencing that allows to detect the nucleotides that are being incorporated to a DNA template mediated by a polymerase. In the reaction mixture, pyrophosphate (PPi) is released as a result of nucleotide incorporation by polymerase. As pyrophosphate is released, it is converted to ATP so that luciferase is activated by the oxidation of luciferin. Luciferase is the enzyme that mediates the reaction that generates light and allows to identify the nucleotides that are being incorporated.
One oak tree cell with 14 chromosomes undergoes meiosis. How many cells will result from this process, and what is the chromosome number in each cell?
Answer:
The correct answer is - 4 and 7 chromosomes in each cell.
Explanation:
Meiosis is the cell division in which one parent cell produces four daughter cells with a half number of the chromosome than parent cells.
According to the question oak cell performed meiosis which is reduction division so the number of cell will be four and 7 chromosome will be present in each daughter oak cell.
Thus, the correct answer is - 4 and 7 number of chromosome in each.
Which of the following is not necessary during Rho-independent termination of transcription?
a. RNA polymerase
b. Rho protein
c. hairpin structure
d. repeating As in the DNA sequence
e. all of the above are necessary
Answer:
Rho protein.
Explanation:
Transcription may be defined as the process of formation of RNA molecule from the DNA template. Three important process of transcription are initiation, elongation and termination.
The termination may occur through rho dependent and rho independent mechanism. In rho independent termination, the rho proteins are not required and not necessary for the termination. The uracil stretch is important for rho independent termination.
Thus, the correct answer is option (b).
Show how selection, genetic drift, gene flow, and mutation relate to genetic variation. Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer.
(1) Gene flow ____ genetic variation of a population
(2) Mutation ____ genetic variation
(3) Selection ____ genetic variation
(4) Genetic drift ____ genetic variation
(A) Increases
(B) May increase, decrease or maintain
(C) Decreases
(D) May increase or decrease
Gene flow, mutation, selection, and genetic drift all play a role in genetic variation. Gene flow increases genetic variation by introducing new alleles, mutation introduces new alleles, selection can increase, decrease or maintain genetic variation, and genetic drift can either increase or decrease genetic variation.
Explanation:(1) Gene flow increases genetic variation of a population. Gene flow occurs when individuals move between populations and bring new alleles with them, increasing the genetic diversity within a population.
(2) Mutation contributes to genetic variation. Mutations are random changes in DNA that can create new alleles, leading to genetic diversity.
(3) Selection may increase, decrease or maintain genetic variation. Natural selection can favor certain alleles, increasing their frequency in a population, while also removing other alleles through selective pressure, which may reduce genetic variation.
(4) Genetic drift may increase or decrease genetic variation. Genetic drift refers to random changes in allele frequencies in a population, which can lead to a loss of genetic diversity in smaller populations.
Learn more about genetic variation here:https://brainly.com/question/848479
#SPJ12
All of the oxygen that we breathe is produced by plants.
a. True
b. False
Answer:
The given statement is true.
Explanation:
The oxygen that is present in the atmosphere has two main sources:
Terrestrial Plants: As we know that the plants make use of sunlight, water, carbon dioxide and chlorophyll in a process termed as photosynthesis and make glucose and releasing oxygen into the atmosphere which is then used by animals for respiration. This is one of the major source of oxygen in the atmosphere.
Oxygen released from Oceans: In the oceans of the earth, water bodies ,seas tiny plants termed as Phytoplankton are present that are present near the surface of the water bodied that also release oxygen by photosynthesis and account for about 50% of the world's oxygen supply.