Explanation

• The autonomic nervous system controls involuntary activities, including heart rate, digestion, and the regulation of breathing.
• Thought is mainly associated with higher brain functions.
• It particularly the cerebral cortex, and is not directly controlled by the autonomic nervous system.
• The autonomic nervous system has two main divisions: the sympathetic division (fight or flight) and the parasympathetic division (rest and digest).

Last verified on 25-10-2026

Explanation

• Follicular atresia is the degeneration and breakdown of ovarian follicles that fail to mature or ovulate.
• It occurs naturally throughout a female’s reproductive life, and most ovarian follicles undergo atresia rather than releasing an egg.
• Follicles that successfully mature may release an egg during ovulation.

Last verified on 25-10-2026

Explanation

• The AV node briefly delays electrical impulses traveling from the atria to the ventricles.
• It allowing the ventricles to fill with blood before they contract.

Additional information:

• The SA node is the natural pacemaker of the heart and initiates each normal heartbeat.

Last verified on 25-10-2026

Explanation

• Arboviruses are viruses transmitted by arthropods, such as mosquitoes and ticks.
• The term comes from arthropod-borne viruses.
• Dengue fever and yellow fever are caused by flaviviruses transmitted mainly by infected mosquitoes.

Last verified on 25-10-2026

Explanation

• Centrioles help organize spindle formation during animal cell division.
• Spindle fibers attach to chromosomes at the kinetochores.
• They are located on the centromere region; they do not attach directly to centrioles.

Last verified on 25-10-2026

Explanation

• High aluminum exposure can be toxic, particularly to the nervous system, and may cause neurological problems.
• Aluminum has been investigated for a possible association with Alzheimer’s disease.

Last verified on 25-10-2026

Explanation

• Amylase is a digestive enzyme that breaks down starch into simpler sugars.
• Mouth / Salivary glands (1): Salivary glands produce salivary amylase, which begins starch digestion in the mouth.
• Pancreas (4): The pancreas produces pancreatic amylase and releases it into the small intestine.
• Small intestine (5): Pancreatic amylase acts in the small intestine to digest starch.
• The small intestine itself does not produce the main amylase enzyme.

Last verified on 25-10-2026

Explanation

• Carl Linnaeus (1707–1778), a Swedish botanist and zoologist, introduced the class name Mammalia in 1758 in the 10th edition of his book Systema Naturae.
• The term Mammalia refers to animals that possess mammary glands and feed their young with milk.
• Linnaeus is widely known as the father of modern taxonomy.
• Because he developed a systematic method of classifying organisms.
• Examples of mammals include humans, whales, bats, elephants, and dogs.

Last verified on 25-10-2026

Explanation

• Variation refers to differences in characteristics among individuals of the same species.
• These differences provide the raw material for evolution.
• Genetic variations arise through mutations and recombination, creating differences that natural selection can act upon.

Last verified on 25-10-2026

Explanation

• A 3:1 phenotypic ratio is classically associated with a monohybrid cross involving complete dominance and Mendelian segregation.
• In a dihybrid cross, linked genes may produce deviations from the expected 9:3:3:1 ratio because linked genes tend to be inherited together.

Last verified on 25-10-2026