Science Flashcards

An unknown element is found to contain 45 protons and an atomic mass of 64, what is its atomic number?

Answer: 45

The atomic number of an element is solely determined by the number of protons in its nucleus. In this case, the unknown element contains 45 protons, so its atomic number is 45. The atomic mass (64) is the sum of protons and neutrons, but it does not define the element's atomic number.

The square above is based on the eye color of two parents, one of whom has brown eyes and carries the recessive gene for green eyes (a). What is the probability that a biological child of these parents will have brown eyes?

Answer: 50%

Assuming 'B' represents the dominant brown eye gene and 'b' represents the recessive green eye gene, and the brown-eyed parent carrying the recessive gene is heterozygous (Bb). If the other parent is homozygous recessive (bb, green eyes), a Punnett square cross (Bb x bb) would yield 50% Bb (brown eyes) and 50% bb (green eyes). Thus, the probability of a child having brown eyes is 50%.

The spleen functions are part of the _____ system. Which of the following completes the sentence above?

Answer: lymphatic

The spleen is a vital organ that functions as a key component of the lymphatic system. It plays crucial roles in filtering blood, removing old or damaged red blood cells, storing blood, and producing lymphocytes, which are essential for immune responses.

Which of the following is an example of deductive reasoning?

Answer: All secretaries are good typists. Cynthia is a secretary. Therefore, Cynthia is a good typist.

Deductive reasoning involves starting with a general statement or hypothesis and then drawing a specific conclusion based on that premise. The example 'All secretaries are good typists. Cynthia is a secretary. Therefore, Cynthia is a good typist' perfectly illustrates this, moving from a general truth to a specific, logical inference.

Which of the following is a possible cause of herniation of discs?

Answer: whiplash

Whiplash is a common injury to the neck caused by a sudden, forceful back-and-forth movement of the head, often from car accidents. This rapid movement can place significant stress on the intervertebral discs in the spine, potentially leading to their bulging or herniation.

Which of the following is a characteristic of the autonomic nervous system?

Answer: It regulates involuntary activity in the heart, stomach, lungs, and intestines.

The autonomic nervous system (ANS) is a division of the peripheral nervous system that controls involuntary bodily functions. It regulates essential internal processes such as heart rate, digestion, respiration, blood pressure, and glandular activity, all without conscious thought or control.

During photosynthesis, which two compounds are combined to create the output of glucose and oxygen?

Answer: Carbon dioxide and water.

Photosynthesis is the fundamental process by which plants convert light energy into chemical energy. The balanced chemical equation for photosynthesis shows that carbon dioxide (CO₂) and water (H₂O) are the primary reactants. These compounds are combined in the presence of sunlight to produce glucose (C₆H₁₂O₆) as food and oxygen (O₂) as a byproduct.

Which of the following is true about the frog?

Answer: It is a type of amphibian.

Frogs are classified under the class Amphibia, which literally means 'double life,' referring to their ability to live both in water and on land. Amphibians are vertebrates characterized by moist skin, the absence of scales, and typically undergoing metamorphosis from an aquatic larval stage to a terrestrial adult stage. Therefore, a frog is definitively a type of amphibian.

Which statement can be inferred about amphibians?

Answer: All amphibians are vertebrates, but not all vertebrates are amphibians.

Amphibians are a class within the subphylum Vertebrata, meaning all amphibians possess a backbone and are thus vertebrates. However, the category of vertebrates is much broader, encompassing fish, reptiles, birds, and mammals in addition to amphibians. Therefore, while every amphibian is a vertebrate, not every vertebrate is an amphibian, making this statement accurate.

In plants, ________ involves the formation of a _____?

Answer: cytokinesis, cell plate

Cytokinesis is the final stage of cell division, where the cytoplasm divides to form two distinct daughter cells. In plant cells, due to the presence of a rigid cell wall, a cleavage furrow cannot form. Instead, a cell plate forms in the middle of the cell, growing outwards to eventually fuse with the existing cell wall and create two separate cells.

Which base is NOT found in DNA?

Answer: uracil

DNA (deoxyribonucleic acid) is composed of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Uracil (U) is a nitrogenous base that is found exclusively in RNA (ribonucleic acid), where it replaces thymine and pairs with adenine. Therefore, uracil is not a component of DNA.

Which of the following layers of the atmosphere is the closest to space?

Answer: thermosphere

The Earth's atmosphere is divided into several layers based on temperature and composition. Starting from the Earth's surface, these layers are the troposphere, stratosphere, mesosphere, and thermosphere. The thermosphere is the outermost layer before the exosphere, which gradually merges with outer space, making it the closest layer to space among the options.

Which is NOT one of the four basic types of tissue?

Answer: parenchyma

The four basic types of animal tissue are epithelial tissue (covers surfaces, lines cavities), connective tissue (supports, protects, binds), muscle tissue (movement), and nervous tissue (communication). Parenchyma, on the other hand, is a type of plant tissue, primarily involved in functions like photosynthesis, storage, and secretion. Thus, parenchyma is not one of the four basic animal tissue types.

The stomach is _____ to the small intestine. Which of the following correctly completes the sentence above?

Answer: superior

In anatomical terms, 'superior' refers to a position above or closer to the head. The stomach is located in the upper part of the abdominal cavity, positioned above the small intestine. Therefore, the stomach is anatomically superior to the small intestine.

How many cells are created at the end of mitosis in a human body cell, and how many chromosomes are present in each cell?

Answer: 2 cells with 46 chromosomes

Mitosis is a type of cell division that produces two genetically identical daughter cells from a single parent cell. In humans, a somatic (body) cell is diploid, containing 46 chromosomes. After mitosis, each of the two resulting daughter cells will also be diploid and contain the full set of 46 chromosomes.

A patient who has suffered head trauma is not able to recognize people he has met around an hour earlier but is still able to recognize people he met before the injury. He most likely has damage to the:

Answer: Hippocampus

The hippocampus is a critical brain structure primarily responsible for the formation of new long-term memories, particularly declarative memories (facts and events). Damage to the hippocampus often results in anterograde amnesia, where individuals lose the ability to create new memories after the injury, while memories formed before the trauma remain largely intact. This precisely describes the patient's symptoms.

What process is illustrated in the diagram above?

Answer: meiosis

Meiosis is a specialized type of cell division that reduces the chromosome number by half, producing four haploid cells from a single diploid cell. This process involves two rounds of division and includes genetic recombination (crossing over), which ensures genetic diversity. It is essential for sexual reproduction, forming gametes like sperm and egg cells.

Of the following, which is not a type of chemical bond?

Answer: magnetic

Chemical bonds are the forces that hold atoms together to form molecules or compounds. The main types of chemical bonds include ionic bonds (formed by the transfer of electrons), covalent bonds (formed by the sharing of electrons), and metallic bonds (found in metals). Magnetic forces are physical forces, not a type of chemical bond that links atoms within a substance.

If the amount of hydrogen in a balloon of fixed size is doubled, what happens to the mass and density of the balloon?

Answer: The mass and density both increase.

Mass is a measure of the amount of matter an object contains. If the amount of hydrogen (matter) in the balloon is doubled, its mass will also double. Density is defined as mass per unit volume (Density = Mass/Volume). Since the balloon's volume is fixed and its mass increases, its density must also increase proportionally.

If you have 200 mL of a 60% sodium chloride solution, how much NaCl is dissolved in the solution?

Answer: 120 g

A 60% sodium chloride solution typically means that there are 60 grams of NaCl dissolved per 100 mL of solution (mass/volume percentage). To find the amount of NaCl in 200 mL, you can set up a proportion: (60 g NaCl / 100 mL solution) = (X g NaCl / 200 mL solution). Solving for X gives X = (60 * 200) / 100 = 120 grams of NaCl.