Science Flashcards

Which of the following describes the flow of oxygenated blood from the heart to the body?

Answer: systemic circulation

Systemic circulation describes the path of oxygenated blood from the left side of the heart, through the aorta and arteries, to deliver oxygen and nutrients to the body's tissues. Deoxygenated blood then returns to the right side of the heart via veins. Pulmonary circulation, in contrast, involves blood flow between the heart and lungs.

In the digestive system of a mammal, nutrient absorption is most likely to happen in which of the following structures?

Answer: duodenum

The duodenum is the first section of the small intestine, and it is the primary site for the chemical digestion of chyme and the absorption of most nutrients. While some absorption occurs throughout the small intestine, and the stomach digests food, the duodenum is where the bulk of nutrient uptake into the bloodstream happens.

A neuron's action potential travels through its axon in a process known as which of the following?

Answer: saltatory conduction

Saltatory conduction is the process by which action potentials rapidly propagate along myelinated axons. The electrical impulse 'jumps' from one node of Ranvier (gaps in the myelin sheath) to the next, which significantly increases the speed of nerve impulse transmission compared to continuous conduction in unmyelinated axons.

When it comes to the human respiratory system, which of the following best describes the process of inhalation?

Answer: the diaphragm contracts and lowers, making the air pressure in the lungs decrease.

During inhalation, the diaphragm muscle contracts and moves downwards, and the intercostal muscles contract, pulling the rib cage up and out. This action increases the volume of the thoracic cavity, which in turn decreases the air pressure inside the lungs relative to the atmospheric pressure, causing air to flow into the lungs.

Which is the correct order of things that happen during an inflammatory response? I. Phagocytes are attracted to the damaged area. II. Blood vessels become permeable. III. Damaged cells release histamine. IV. The formation of pus occurs.

Answer: III, II, I, IV

The inflammatory response is a protective mechanism. It starts with damaged cells releasing histamine (III), which causes local blood vessels to dilate and become more permeable (II). This allows immune cells like phagocytes to be attracted to the area (I) to clear debris and pathogens. The accumulation of these cells and fluid can lead to pus formation (IV).

The decline in newborn mortality rates in developed countries is attributed to which of the following?

Answer: the education opportunities provided to woman.

Increased educational opportunities for women are strongly linked to improved health outcomes for both mothers and newborns. Educated women are more likely to have better knowledge of health, nutrition, hygiene, and family planning, and are more empowered to seek and utilize healthcare services, all of which contribute to lower newborn mortality rates.

Choose the scenario that most effectively exemplifies carrying capacity.

Answer: A population of deer increases exponentially, but then decreases due to starvation, then increases slightly again.

Carrying capacity refers to the maximum population size that an environment can sustainably support. Option A demonstrates this by showing a population initially growing rapidly, then exceeding the environment's capacity (leading to starvation and a decrease), and finally fluctuating around a sustainable level, which is characteristic of populations reaching carrying capacity.

Which is more likely to happen after a population near an open body of water experiences both immigration and emigration?

Answer: the population will increase if the rate of immigration is greater than the rate of emigration.

Population size is influenced by births, deaths, immigration (individuals entering), and emigration (individuals leaving). If the rate of immigration is higher than the rate of emigration, more individuals are entering the population than leaving, which will lead to an overall increase in population size, assuming other factors like birth and death rates are constant or favorable.

Which of the following is most likely taking place in populations that are supposedly in a zero-growth phase?

Answer: the death and emigration rates equal the birth and immigration rates.

A zero-growth phase in a population occurs when the total number of individuals added to the population (births + immigration) is equal to the total number of individuals removed from the population (deaths + emigration). This balance results in a stable population size, neither increasing nor decreasing.

What will happen if the aorta isn't working properly?

Answer: oxygenated blood would not be transported to the body’s cells.

The aorta is the body's largest artery, responsible for carrying oxygenated blood from the left ventricle of the heart to the rest of the body's cells and tissues. If the aorta is not functioning correctly, this vital distribution of oxygen-rich blood would be impaired, preventing cells from receiving the oxygen they need.

The atomic mass of an unknown element is 64, and it has 45 protons. What is its atomic number?

Answer: 45

The atomic number of an element is defined solely by the number of protons in the nucleus of its atoms. It is a unique identifier for each element. Therefore, if an element has 45 protons, its atomic number is 45, regardless of its atomic mass.

Given that one parent has brown eyes, and another contains the recessive gene for green eyes, we get the above square (a). How likely is it that a child born to these two people will have brown eyes?

Answer: 50%

Brown eyes (B) are dominant over green eyes (b). If one parent has brown eyes and carries the recessive gene (Bb), and the other parent has green eyes (bb), a Punnett square shows the possible offspring genotypes. The cross Bb x bb yields two Bb (brown eyes) and two bb (green eyes) outcomes. Therefore, there is a 50% chance for a child to inherit brown eyes.

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

Answer: lymphatic

The spleen is a vital organ that is part of the lymphatic system, which is a component of the immune system. Its primary functions include filtering blood, removing old or damaged red blood cells, storing platelets, and producing white blood cells (lymphocytes) to fight infection. These roles are central to lymphatic and immune system health.

Disc herniation discs can be caused by which of the following?

Answer: whiplash

Disc herniation occurs when the soft inner material of an intervertebral disc protrudes through a tear in its tougher outer layer. Whiplash, a sudden and forceful back-and-forth motion of the neck, can cause significant trauma to the spinal column. This abrupt stress and stretching can lead to tears in the disc's outer layer, resulting in a herniated disc.

Which of these describes the autonomic nervous system?

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

The autonomic nervous system (ANS) is responsible for regulating involuntary bodily functions that occur without conscious control. This includes essential processes such as heart rate, digestion, respiration, blood pressure, and glandular secretions. It operates automatically to maintain the body's internal balance, or homeostasis.

To produce glucose and oxygen, photosynthesis requires the combination of which two compounds?

Answer: Carbon dioxide and water.

Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy. The essential raw materials for this process are carbon dioxide (CO2), absorbed from the atmosphere, and water (H2O), absorbed from the soil. These compounds are transformed into glucose (sugar) and oxygen using sunlight as an energy source.

Which of these about the frog is true?

Answer: It is a type of amphibian.

Frogs are classic examples of amphibians, a class of vertebrates known for their dual life cycle, typically involving an aquatic larval stage and a terrestrial adult stage. They possess moist, permeable skin and rely on water for reproduction. This classification distinguishes them from reptiles, fish, or non-vertebrates.

Which of the following statements about amphibians is true?

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 therefore vertebrates. However, the category of vertebrates is much broader, encompassing fish, reptiles, birds, and mammals in addition to amphibians. Thus, while all amphibians are vertebrates, not all vertebrates are amphibians.

Head trauma patients may recognize people they met before the accident but not those they met an hour earlier. He has probably suffered damage to:

Answer: Hippocampus

The hippocampus is a critical brain structure located in the medial temporal lobe, playing a major role in the formation of new long-term memories. Damage to the hippocampus typically results in anterograde amnesia, where individuals can recall events from before the injury but struggle to create new memories for events occurring after the trauma.

In DNA, the double helix structure is held together by what kind of bond between the complimentary bases?

Answer: hydrogen

The double helix structure of DNA is stabilized by hydrogen bonds that form between complementary nitrogenous bases on opposite strands. Adenine (A) always pairs with thymine (T) via two hydrogen bonds, and guanine (G) always pairs with cytosine (C) via three hydrogen bonds. These relatively weak bonds allow the strands to separate for replication and transcription.