Question 15 the decrease in estrogen in postmenopausal women plays a part in the increased risk of heart disease that occurs in older women.
a. True
b. False

The type of microscope that requires a nonmetal sample to be prepared for viewing by coating it with a thin layer of a conductive material is the Scanning Electron Microscope (SEM).

A scanning electron microscope (SEM) is a type of microscope that uses electrons to image the surface of a sample. It provides high-resolution, three-dimensional images of the sample's surface topography and composition.

In an SEM, a focused beam of electrons is scanned across the sample surface. When the electrons interact with the atoms on the sample, various signals are generated. These signals, including secondary electrons, backscattered electrons, and characteristic X-rays, are detected and used to create an image.

The electron beam in an SEM is typically generated by an electron gun and focused using electromagnetic lenses. The scanning coils direct the beam in a raster pattern across the sample. By adjusting the beam intensity and scanning parameters, detailed images with high magnification can be obtained.

SEM is widely used in various scientific fields, such as materials science, biology, geology, and nanotechnology. It allows for the visualization and analysis of the surface features, morphology, and elemental composition of a wide range of samples, providing valuable insights into their microstructure and properties.

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The correct answer is A. Release of adrenaline by the adrenal glands

Explanation:

The "fight or flight" response is a natural response to a possible threat or attack. During this, the endocrine system and more specifically the adrenal glands react by releasing substances such as adrenaline, noradrenaline, and other hormones. These substances make the body to be alert and prepare to either scape and avoid the threat (flight) or face it (fight). Additionally, this response has also multiple effects in the body that includes the dilatation of the pupils, an increase in the heart and breath rate, and trembling; however, once the threat disappears the body goes back to a normal state. According to this, during the "fight or flight" response in the endocrine system adrenaline is released by the adrenal glands.

Natural selection of organisms is affected by such factors as genetic differences, number of offspring, and death.

Natural selection is the process by which individuals who are better suited to its environment are selected naturally by environmental factors to survive.

Factors that affect natural selection include:

Genetic differences ensure that those organisms with better genetic makeup survive.

The higher the number of offspring produced, the more the chances of survival.

An increased death rate among species reduces the chances of survival and vice versa.

Therefore, natural selection of organisms is affected by such factors as genetic differences, number of offspring, and death.

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The statement that would most likely cause a mutation is the insertion of a nucleotide into DNA. Thus, the correct option for this question is B.

A Mutation may be defined as the process through which sudden, stable, and inheritable changes have been occured within the DNA sequence of an organism. The organism which undergoes mutation is known as a Mutant. The agents of mutation are known as Mutagens.

A Mutation is of two types. Gene mutation and Chromosomal mutation. Gene mutations are again subdivided into point mutation and frameshift mutation. While chromosomal mutations are structural variations and numerical variations.

This insertion of any nucleotide is facilitated by the action of any mutagen such as UV radiation, any chemical like ethidium bromide, etc.

Therefore, the insertion of a nucleotide into DNA is the statement that would most likely cause a mutation. Thus, the correct option for this question is B.

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To complete the analogy, we would say the nucleus is to cell as the A. hormone is to gland. The nucleus directs the activities within the cell, and in a similar vein, glands control various functions by producing hormones.

The nucleus is the control center of the cell, directing the synthesis of ribosomes and proteins, just as a gland produces and releases hormones that regulate various bodily functions. In each case, the component mentioned plays a central role in the functioning of the whole.  In analogy parallels, cytoplasm is to cytosol as a swimming pool containing chlorine and flotation toys is to the water.

Cytoplasm includes both the cytosol, which is the intracellular fluid, and the organelles suspended within it, much like a swimming pool's water includes both the water itself and the items floating in it. Similarly, diffusion is to spread as endocytosis is to engulf. Diffusion involves the spread of particles from areas of high concentration to low concentration, while endocytosis is a process by which a cell envelops material from the outside environment, bringing it into the cell in a vesicle.

Answer:

The correct abbreviatipon for Zinc is Zn

Explanation:

Z is the first letter taken from the elment Zink and the n taken from the n in Zink

In photosynthesis, energy is transferred from pigment to pigment within the light-harvesting complex without the transfer of electrons. Only when this energy reaches the reaction center does a special chlorophyll a molecule give up an excited electron. Thus, one electron at a time is passed between pigment molecules in the light-harvesting complexes of photosystems.

In the process of photosynthesis, pigments within the photosynthetic membranes are organized into photosystems. Each photosystem consists of a light-harvesting complex and a reaction center. The light-harvesting complex is made up of numerous proteins and pigments that each may absorb light energy and thus, become excited. The energy is transferred from one pigment molecule to another within this complex, but up to this point, only energy, not electrons, has been transferred.

Pigments in the light-harvesting complex pass the light energy to one or two special chlorophyll a molecules located in the reaction center. Upon excitement from light energy absorption, these molecules give up an electron, which is passed to the primary electron acceptor. This is the point in photosynthesis where light energy is converted into an excited electron. Therefore, only one electron at a time is passed between the pigment molecules in the light-harvesting complex of each photosystem.

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Index fossils delineate the epochs of geologic time. In order for an organism to be considered as an index fossil it must possess at least one of the four characteristics: it must be unique, extensive, abundant and inadequate in geologic time. Most type of organism may be considered distinctive but not widespread which tolerate them to inhabit all over the world. While some are considered abundant that they were able to be developed as the most susceptible to environmental modification and destruction. Just like the trilobites, this is known as a precise example of index fossil for the Paleozoic rocks that is inhabit in all parts of the ocean. They develop new species throughout their being, which is according to some reports, lasted 270 million years from Middle Cambrian time to the termination of the Permian Period. Because of their ability to travel, they tend to dwell in global areas. The trilobites are huge that they can be used in a study even without a microscope and they are also hard-shelled invertebrates which make them petrified effortlessly.

Trilobites are considered excellent index fossils because they were geographically widespread, each species existed for a relatively short period of geologic time, they were abundant, and they have easily distinguishable features.

To understand why trilobites are considered to be good index fossils, we must first look at the four criteria that qualify an organism as an index fossil.

Collectively, these characteristics make trilobites excellent index fossils for determining the ages of rock layers. When scientists find trilobite fossils, they are able to narrow down the age of rock layers to specific periods within the Paleozoic Era.

Answer:

Phospholipids

Explanation:

Answer:

The correct answer is Africa.

Explanation:

Any member of the biological family Hominidae is known as a hominid. These are considered as the great apes that have become extinct and are living. At present, there are chimpanzee, orangutans, humans, and gorillas. The hominids originated on the continent Africa, mainly in the Eastern parts of Africa. The hominids dispersed to other continents from Africa.

The first law of thermodynamics states that energy can neither be created nor destroyed, but it can change from one form to another.

answer:B

The second option, Photosynthesis makes the glucose that is broken down by cellular respiration.

The relationship between photosynthesis and cellular respiration is that photosynthesis makes the glucose that is broken down by cellular respiration.

photosynthesis refers to a process used by algae, plant or photosynthetic organisms to capture energy from sunlight to produce chemical energy.

During photosynthesis, the oxygen generated by plants is what animals and humans breathe in for blood to move to the body cells for respiration

However, there are processes involved in photosynthesis.

The two processes include:

The principles involved in both photosynthetic processes are very similar but the most common process is oxygenic photosynthesis. oxygenic photosynthesis is seen in cyanobacteria, algae, and plants.

During photosynthesis, the light is captured from the sun and used to transformed carbon dioxide, water and mineral into energy-rich compounds and oxygen.

photosynthesis is very important in the maintenance of life because if the process of photosynthesis stops, there will be a shortage of foods and the presence of organic matter on earth will reduce drastically.

Most organisms will no longer exist and there would be less oxygen and more carbon dioxide in the atmosphere.

However, while photosynthesis required the use of energy from the sunlight, water and carbon dioxide to generate oxygen and glucose, cellular respiration involves the use of oxygen and glucose to generate water and carbon dioxide.

Plants and animals, even human rely on photosynthesis and cellular respiration to survive.

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Answer:The correct answer is 38

Explanation:

Answer:

Tonia is a very expressive person, while Robert is more reserved.

Explanation:

Tonia is very easy to express what she is feeling. She makes her emotions very clear, because she can externalize them so quickly. Therefore, by looking at Tonia we are able to identify that she likes Robert, and we are able to identify any other feelings she may be feeling. Tonia is very expressive.

On the other hand, Robert is a more reserved person. He has difficulty expressing his feelings, although he can develop strong and impactful feelings. Robert likes tonia, but unlike her, he can't externalize his emotions, so we can't know what he's feeling when we look at him.

In the event of a cut as a result of a broken glass, a series of fundamental steps must be followed to prevent this situation from becoming more serious:

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Answer:

A. Osmosis occurs through a semipermeable membrane. Diffusion occurs through a permeable membrane.

Explanation:

Diffusion is the transport of membrane permeable substances. These, in solution, can flow from the inside out of the cell or vice versa spontaneously. This process occurs from a region with higher particle concentration to one with lower concentrations. Gas exchange between blood and tissues is an example of this type of transport.

On the other hand, osmosis is a process of diffusion of water through a semipermeable membrane and occurs from the less concentrated to the most concentrated solution. This process is a type of passive transport because during osmosis the cell does not waste energy.

Based on this, we can say that what makes osmosis different from diffusion is that osmosis occurs through a semipermeable membrane, whereas diffusion occurs through a permeable membrane.