Answer:
cells duplicate so when there is no cell it cant make any
Explanation:
The statement that there must be a preexisting cell in order for a new cell to form is known as cell theory.
What is cell theory?The scientific idea that cells make up living organisms, that they are the fundamental structural and organizational unit of all species.
They all originate from previously existing cells is known as cell theory. It was first proposed in the middle of the nineteenth century.
Because cells are the building blocks of all life, cell theory is essential for our understanding of biology.
We can have single-celled organisms like yeasts and bacteria. All living things grow and develop on the basis of cell division, or the division of a cell from one to two to four.
A vital process for life is mitosis. A cell divides into two identical daughter cells after duplicating all of its components, including its chromosomes.
Thus, the statement "cell arises from pre-existing cells" comes from cell theory.
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What is a group of microscopic unicellular organisms
In pulsus paradoxus, even if the pulse cannot be palpated, it can still be heard by using a BP cuff and stethoscope.
a. True
b. False
Answer:
False.
Explanation:
Pulse can't be heard by using a BP cuff and stethoscope because these devices are used to measure the heartbeat and blood pressure of the body. Digital monitors display both blood pressure and heart rate, but you can determine the pulse by checking your pulse by using hand while on the other hand, heartbeats can easily be heard using a good stethoscope so we can say that pulse can't be heard through BP cuff and stethoscope.
What are three techniques that can be used to show that the electron transport chain is found on the matrix side of the inner mitochondrial membrane. Select all that apply.
Answer:
Explanation:
Step 1: Generating a Proton Motive Force
The hydrogen carriers (NADH and FADH2) are oxidised and release high energy electrons and protons
The electrons are transferred to the electron transport chain, which consists of several transmembrane carrier proteins
As electrons pass through the chain, they lose energy – which is used by the chain to pump protons (H+ ions) from the matrix
The accumulation of H+ ions within the intermembrane space creates an electrochemical gradient (or a proton motive force)
Step Two: ATP Synthesis via Chemiosmosis
The proton motive force will cause H+ ions to move down their electrochemical gradient and diffuse back into matrix
This diffusion of protons is called chemiosmosis and is facilitated by the transmembrane enzyme ATP synthase
As the H+ ions move through ATP synthase they trigger the molecular rotation of the enzyme, synthesising ATP
Step Three: Reduction of Oxygen
In order for the electron transport chain to continue functioning, the de-energised electrons must be removed
Oxygen acts as the final electron acceptor, removing the de-energised electrons to prevent the chain from becoming blocked
Oxygen also binds with free protons in the matrix to form water – removing matrix protons maintains the hydrogen gradient
In the absence of oxygen, hydrogen carriers cannot transfer energised electrons to the chain and ATP production is halted
Sickle cell anemia in the United States disproportionately affects African Americans; 1 in 700 African Americans are affected by sickle cell anemia, while only 1 in 160,000 Americans of European descent are affected. The absolute risk of a newborn African American child having sickle cell anemia is ____________%, and the relative risk compared to a newborn European American child is ____________-fold
Answer:
0.0014; 0.0044
Explanation:
The absolute risk (AR) of a disease refers to the risk of developing the disease over a given time period. In this case, the absolute risk of the newborn African American child having sickle cell anemia is equal to 1 individual with the disease over 700 individuals >> AR = 1 / 700 = 0.0014. Moreover, the Relative Risk (RR) is calculated by comparing the likelihood of the absolute risk occurring between two distinct groups. In this case, the relative risk for the newborn African American having sickle cell anemia compared to a newborn European American child can be calculated by dividing the absolute risk of the newborn European American child with the measured absolute risk of the newborn African American child >> RR = 0.0000625 / 0.0014 = 0.0044.
What process adds carbon dioxide to the air?
O nitrogen cycle
O water cycle
O respiration
O photosynthesis
Answer:
Respiration
Explanation:
During respiration, oxygen is taken in and carbon dioxide is given out.
During photosynthesis, carbon dioxidr is taken in and oxygen is released.
During water cycle, water vapour is released.
During nitrogen cycle, nitrogen is released
Answer:
Respiration or C
Explanation:
What is the correct volume of air to deliver during BVM ventilations?
Individuals with premutation length repeats in FMR1 may have some of the phenotypes of Fragile X but not others, which is _____________; for example, some individuals may have cognitive deficiencies, while others might have late onset ataxia. In addition, some individuals will have no phenotypes of the condition at all, due to ____________.
Answer:
variable expressivity; incomplete penetrance
Explanation:
In genetics, variable expressivity refers to the fact that individuals having the same alleles/genes/genotype associated with a particular genetic condition may exhibit different clinical features of this condition. In general, variable expressivity is due to the combination of both genetic and environmental factors. An example of variable expressivity is the Marfan syndrome, where all individuals with this disorder have a dominant mutation in the FBN1 (fibrillin 1) gene and show different degrees of the same phenotype. Moreover, incomplete penetrance (also known as reduced penetrance) refers to the complete absence of a genetic trait or disease in individuals having alleles/genes/genotype associated with the condition. In consequence, individuals with incomplete penetrance do not develop features of the disease. An example of incomplete penetrance is given by those individuals with mutations in BRCA1/BRCA2 genes (associated with an increased risk of developing breast cancer) that do not develop cancer.
14.
(GT.03)
Which of these best matches a source of information with its most reliable use? (2 points)
cladogram → date events which occurred in Earth's past
cladogram → study the evolution of organisms based on adaptations
fossil records → compare the evolution of completely soft-bodied organisms
fossil records → study the behavior of primitive animals in extreme weather conditions
Answer:
petrified fossils → date sedimentary rocks
QUESTION 16 Why does spoiled food become more sour? Spoilage microbes produce acid The nutrients in juice react with its packaging More hydrogen ion is consumed by spoilage microbes Enzymes in juice generate more hydroxide
Answer:
Spoilage microbes produce acid
Explanation:
When food becomes spoiled or is unprotected, bacteria will invade the food. These types of bacteria are called spoilage bacteria. The bacteria will multiply by consuming the nutrients from the food and grows very rapidly. In certain conditions, the invading bacteria will produce acids that protects them and creates a barrier for other microbes. This acid is what gives spoiled food a sour taste.
Question 4 Multiple Choice Worth 2 points)
In the diagram below, what is the property of the wave indicated by the letter A?
- amplitude
- crest
-frequency
-trough
Answer:
- trough.
Explanation:
The Trough is the lowest wave section, the minimum wave part. It's the other way around from crest.A wave or alternating signal minimal point.A long, narrow depression, waves or ridges between them.A low point in a corporate cycle or on a graph.An extended area of relatively low pressure, often in conjunction with the front.What is the complementary DNA strand for this DNA strand : GTTACGAACT
Answer:
CAATGCTTGA
Explanation:
A membrane consisting only of phospholipids undergoes a sharp transition from the crystalline form to the fluid form as it is heated. What would be the effect on this transition in a membrane containing 80% phospholipid and 20% cholesterol
Answer:
Having 20% cholesterol in a membrane would reduce the fluidity.
Explanation:
At high temperatures, cholesterol stabilizes the membrane and increases the melting point.
The plasma membrane is the layer that surrounds the cell and is composed of cholesterol and phospholipid. The presence of cholesterol reduces the fluidity and transition.
What are the components of the plasma membrane?The plasma membrane separates the exterior and the interior of the cell and through a semi-permeable nature allows the transport of the molecules. It is composed of phospholipids and cholesterol molecules.
The phase transition of the membrane is known by the change in the rigidity as it starts free-flowing at a high temperature called transition temperature.
In the presence of cholesterol, the movement and the fluidity reduce as it interferes with the fatty acid chain and now requires more temperature to convert the rigid structure to become fluid.
Therefore, membrane-containing cholesterol requires more temperature to modify the fluidity as compared to phospholipids alone.
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Solutions having osmotic pressures more than those of body fluids are called Group of answer choices hyposmotic. neosmotic. hyperosmotic. magnosmotic. isosmotic.
Answer:
hyperosmotic
Explanation:
Osmosis across a membrane occurs in nature as a result of concentration gradient i.e. difference in the solute concentration. Based on the concentration of solute in a solution which determines the osmotic pressure, a solution can either be hyperosmotic, hypoosmotic or isosmotic.
A hyperosmotic solution is that solution which contains more solute concentration in relation to another solution. In essence, a hyperosmotic solution will have more osmotic pressure than that of the body fluid. This will cause water to flow out of the body into the solution.
Answer this question properly
What do proteins, nucleic acids, and carbohydrates all have in common?
In which process do producers use chemi-
cal energy and make food?
A chemosynthesis
B fermentation
C glycolysis
D photosynthesis
Answer: D, Photosynthesis
Explanation:
photosynthesis is the process plants use to make food :)
You isolate a variant of the Hfr parent in question 6 that only shows recombination of the his+ and trp+ genes. The cross was ( HFR lac+, gal+, trp+, his+, strr X F- lac-, gal-, trp-, his-, strs ). This strain most likely:_________.
a. Contains an F' his+ trp
b. Has become F-
c. Contains an Hfr translocation
d. No longer mates as a merry diploid
e. Not enough information is given
Answer:
The correct answer is - b. has become F-.
Explanation:
In the case of the cross of two different strains, some genetic material moves to the F- strain from the Hfr strain, but due to genome size, it's not possible that all the genes can pass into a single bacterium.
Instead of complete transfer, each individual F- cell gets a different and random subset of genes from the Hfr. There is no translocation and F' does not contain his+ trp+.
During which trimester of a woman's pregnancy do the toenails, lips, and eyelashes of the fetus usually appear?
O A. First trimester
O B. Fourth trimester
O C. Second trimester
O D. Third trimester
It is
Explanation: Second Trimester: The Baby at 20 Weeks
Your baby is covered by fine, feathery hair called lanugo and a waxy protective coating called vernix. Eyebrows, eyelashes, fingernails, and toenails have formed. Your baby can even scratch itself. Your baby can hear and swallow.
Activity 3: Direction: Study the picture. Write the phases of the moon 1 new moon O first quarter O MOON PHASES last quarter waning crescent woving crescent Waning gibbous working globos
Answer:
1.full moon
2.waxing gibbous
3.first quarter
4.waning gibbous
5.new moon
6.wabing cresent
7.last quarter
8.waxing cresent
Methylene blue can be used to stain DNA because it: (2 pts) forms ionic bonds with DNA changes the pH and therefore the structure of DNA makes DNA electron dense is an effective chemical fixative for cells is none of the above
Answer: Methylene blue can be used to stain DNA of a cell because it (forms ionic bonds with DNA).
Explanation:
To examine the components of a cell usually under a microscope, a stain or dye is being used to provide a clear and defined view of the area under study.
The deoxyribonucleic acid (DNA) of a cell which contains the hereditary information of the cell is located in the nucleus.
Methylene blue is a type of stain used by biologists which helps them view microscopic life in brilliant color. It is a cationic stain (positively charged blue dye); and binds to negatively charged parts of the cells, such as nucleus (DNA) and RNA in the cytoplasm (with lower affinity).
When DNA of a cell comes in contact with methylene blue on a slide, their opposite charges attract, causing methylene blue's "rings" to slide in between the "rungs" of the DNA "ladder." As a result, a rich blue stain that identifies the location of the cell nucleus can be observed. This produces a photosensitive reaction which can then be viewed under the microscope.
Therefore is can be used to stain the DNA of cell because it forms ionic bonds with DNA.
What is silk thread?
2. The process of obtaining and using energy is called
metabolism
O photosynthesis
reproduction
homeostasis
Explanation:
the answer is photosynthesis because it oxidizes It produces energy by producing its own food, that is, it produces ATB.
exercises to do when have operation?
Answer:
You can do Yoga, Swimming, Biking. Generally, you want to take extra care of the affected area. At the same time, it is almost always helpful to get moving.
Explanation:
2. The process of obtaining and using energy is called
metabolism
O photosynthesis
reproduction
homeostasis
Answer:
metaboliam is the ans of this question
Use the coordinates of the labeled point to find the point-slope equation of
the line
-5
5
-5
(3.-5)
O A. y+ 5 = -3(x - 3)
B. y- 5 = -3(x+3)
C. y + 5 = 3(x+3)
O D. Y-3 - (x+5)
Answer:
A. y + 5 = -3(x - 3)
Explanation:
Given the following data;
Points on the graph (x1, y1) = (3, -5)
Points on the graph (x2, y2) = (0, 4)
First of all, we would determine the slope of the equation of line;
Mathematically, the slope of a line is given by the formula;
[tex] Slope, \ m = \frac {Change \; in \; y-axis}{Change \; in \; x-axis} [/tex]
[tex] Slope, \ m = \frac {y_{2} - y_{1}}{x_{2} - x_{1}} [/tex]
Substituting into the formula, we have;
[tex] Slope, \ m = \frac {4 - (-5)}{0 - 3} [/tex]
[tex] Slope, \ m = \frac {4 + 5}{0 - 3} [/tex]
[tex] Slope, \ m = \frac {9}{-3} [/tex]
Slope, m = -3
Next, to find the point-slope equation of the line, we would use the following formula;
y - y1 = m(x - x1)
y - (-5) = -3(x - 3)
y + 5 = -3x + 9
y = -3x + 9 - 5
y = -3x + 4 = mx + c
Complete the sentences on the control of the cell cycle with the correct terms. After S phase ____________ appear to share a common centromere.
Answer:
After S phase sister chromatids appear to share a common centromere.
Explanation:
The cells of the different organisms go through different periods during their life, each one characteristic and well differentiated. Before the mitosis process, during the S phase of the cell cycle, the chromosomes replicate, so that at the time of initiating cell division in humans, each of the 46 replicated chromosomes will have two chromatids joined by the centromere, each one of them represents a functional chromosome. Each sister chromatid of a chromosome secretes a daughter cell, as do the other 45, and together they will make up the diploid "cluster" of 46 chromosomes from the new cell. In other words, each chromosome is made up of two chromatids that come together at a point called the centromere. One chromatid contains a condensed chromatin molecule and the other has another identical chromatin molecule, the result of DNA replication, which is why we talk about a sister chromatid chromosome. Each chromatid has two arms of equal or different length.
The negative effects of chemical control of weeds on rangelands
Answer:
Chemical residue remain on the vegetation.
Explanation:
The negative effects of chemical control of weeds on rangelands is that the chemical residue remain on the vegetation in rangeland which is dangerous for animals that feed on vegetation because the chemicals are toxic that cause serious damaged. Sometime the chemical also damaged the weeds as well as vegetation of rangelands and also kill the beneficial insects that is needed by the plants present in rangelands.
The only Purple Animal is the South African____?
Answer:
Okapi
Mark Brainliest
okapi...
hopr helps uh
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A scientist finds that another molecule has contaminated the mixture he is working with in the lab. When he analyzes its chemical structure, he finds that it contains uracil, is single stranded, and contains phosphate. What molecule has likely contaminated his mixture?
nucleotide
protein
DNA
RNA
Answer:
RNA
Explanation:
A ribonucleic acid (RNA) is one of two types of nucleic acid made up of nucleotide subunits. RNA is a single stranded molecule unlike DNA, which is double stranded. The nucleotide unit of nucleic acids is composed of a nitrogenous base (Adenine, Guanine, Cytosine and Thymine/Uracil), a pentose sugar (ribose and deoxyribose) and a phosphate group.
One of the key structural differences between RNA and DNA is that RNA contains URACIL nitrogenous base instead of THYMINE in DNA.
According to this question, a scientist finds that another molecule has contaminated the mixture he is working with in the lab. When he analyzes its chemical structure, he finds that it contains uracil, is single stranded, and contains phosphate. This illustrates that the contaminating molecule is a specific type of nucleic acid called RNA.
Answer:
rna
Explanation:
What organisms help break down dead leaves in an ecosystem
Answer:
Decomposers are vital organisms that grow by breaking down dead and decaying matter. Some of these are scavengers - macro-organisms that feed on dead or decaying matter, e.g. flies, cockroaches, earthworms. Others are decomposers, generally microscopic bacteria and fungi, that break down wastes.
Explanation: