A nation in a phase of zero population growth has steady population numbers. This can happen if the birth rate is the same as the death rate and if the emigration rate is the same as the immigration rate.
Basically, each person who dies or moves away is replaced by someone who moves in or is born.
The right choice is D. The autonomic nervous system regulates processes like digestion, heart rate, respiratory rate, sweating, salivation, swallowing, and breathing below the level of consciousness, whereas the somatic nervous system regulates overt activities. The brain and spinal cord are both a part of the central nervous system.
Through the mouth, food enters the digestive tract where it is masticated (chewed) and starts to break down due to salivary amylase. The meal, which is now referred to as the ""bolus,"" is swallowed with the help of the epiglottis, a cartilaginous flap that closes over the trachea, and is subsequently moved to the stomach by esophageal muscular contractions.
The bolus is mostly chemically digested in the stomach, where it is liquefied into chyme and then transferred to the duodenum of the small intestine. Most nutrient absorption takes place in the duodenum of the small intestine.
Despite being a part of the digestive system, the cecum is located in the large intestine, where water absorption causes the chyme to harden into feces.
The right choice is B. Plants use the process of photosynthesis to convert carbon dioxide and water into glucose and oxygen.
The right response is D. Memory is stored in the hippocampus. The corpus callosum connects the two lobes and regulates emotions, the medulla oblongata is engaged in involuntary controls, and the pituitary gland is an endocrine organ.
Infant mortality rates have decreased in most developed countries as a result of improved access to education and methods of birth control among women.
Nutrition, personal care, and baby development are better understood when mothers have greater knowledge about how to safeguard their young children throughout pregnancy and the first two years of life.
The right choice is B. Two of the kids in the Punnett Square image have brown eyes (A) and possess the recessive green gene (a) = (Aa), whereas two of the kids have green eyes (aa). These parents have a 50 percent probability of having children with brown eyes (Aa).
Some parts of the axon's myelin sheath are not covered with myelin. The name for these parts is Nodes of Ranvier. Electrical impulses "jump" from one node to the next when an action potential travels along an axon.
Saltatory conduction is the movement of the action potential along the axon.
In contrast to emigration, which is the movement of people out of a population, immigration is the movement of people into a population. The number of people in a country is based on the rates of immigration, emigration, births, and deaths.
Since neither the birth rate nor the death rate are specified, it is presumed that they are both constant. If immigration is higher than emigration, it means that more people are coming into the population than leaving, which means that the population is growing.
The right choice is B. The atomic number of an atom is the same as the number of protons in its nucleus. The atomic mass is given to be 64 and the number of protons to be 45; however, the atomic mass is not required to find the atomic number. So, the number of the atom is 45.
The right choice is B. Even if all amphibians are found within the "circle" of vertebrates, there is no evidence that ALL vertebrates are amphibians.
To drive air out of the lungs during exhalation, the air pressure inside the lungs must increase to a level higher than the surrounding atmosphere. The diaphragm relaxes and moves up to raise pleural pressure.
During inhalation, the diaphragm contracts and lowers itself, causing the volume of the lungs to increase and the pressure in the lungs to drop. This makes it easier for air to get into the lungs.
The aorta carries oxygenated blood away from the heart and into the body's upper and lower extremities.
Cells need oxygen to execute cellular respiration and create energy within the cell, thus if the aorta isn't working properly, oxygenated blood won't be pumped to the rest of the body and eventually, cells will die.
Blood travels from the heart to the lungs to absorb oxygen and from the heart to the body's cells as part of the circulatory system.
Systemic circulation refers to the latter circulation, whilst pulmonary circulation refers to the former.
The right choice is B. The double helix shape of DNA is held together by hydrogen bonds between the bases.
The right choice is A. The frog fits inside the triangle, and the key says that the triangle stands for amphibians, therefore it is logical that frogs are amphibians.
Chemical signals are released by damaged cells during an inflammatory reaction, signaling white blood cells to the injury site. Histamines, the most typical of these indications, cause the capillaries in the region to become "leaky" or "permeable," allowing phagocytic white blood cells to exit the artery and go to the wounded area, where they consume any dead cells or debris that has made its way there.
Near the wound, the phagocytes also die and turn into pus. Eventually, the pus turns into a scab, which closes the wound.
The right choice is D. Neutrons, protons, and electrons are all parts of an atom's nucleus, but only neutrons and protons are found inside the nucleus. Electrons form a cloud around the nucleus, so you can't find them inside it.
The carrying capacity of a location is the maximum number of people who can live there sustainably. Water, food, space, and even mates become rare when populations approach carrying capacity, forcing species to struggle for these restricted resources at higher intensities.
When resources become so scarce that people have to die to stop competition and make better use of what's already there, populations often drop below their carrying capacity. A is the only answer option that demonstrates this.
The right response is C. Part of the lymphatic system is the spleen. It serves as a blood filter just like the lymph nodes do.
The right choice is A. Herniation of a disc happens when the inner core of a disc in the spine pours through the disc's exterior. An injury to the back or spine may also result in this kind of spinal injury. Whiplash caused by a mild hit might result in a herniated disc.
