Explanation

• Each amino acid has a specific R-group (side chain) that determines its chemical properties and influences how its carbon skeleton is metabolized.
• During protein metabolism, amino acids undergo deamination, in which the amino group is removed.
• Their remaining carbon skeletons can enter energy-producing pathways at different points.

Last verified on 25-10-2026

Explanation

• The apoplast pathway transports water through cell walls and intercellular spaces without crossing the plasma membrane at every cell.
• At the endodermis, the Casparian strip blocks the apoplast pathway, forcing water to cross a cell membrane before entering the vascular tissue.

Additional information:

• The symplast pathway carries water through the cytoplasm of adjacent cells connected by plasmodesmata.

Last verified on 25-10-2026

Explanation

• The lingual frenulum is a fold of mucous membrane that connects the underside of the tongue to the floor of the mouth.
• It helps stabilize the tongue while allowing movements needed for speaking, swallowing, and eating.

Last verified on 25-10-2026

Explanation

• A hypertonic solution has a higher solute concentration than the inside of the cell.
• Water moves out of the cell by osmosis, causing the cell to shrink.

Additional information:

• A hypotonic solution has a lower solute concentration, so water tends to enter the cell.
• An isotonic solution has an equal effective solute concentration.

Last verified on 25-10-2026

Explanation

• Glycolysis is the first stage of cellular respiration, in which one glucose molecule is broken down into two molecules of pyruvate.
• This process occurs in the cytoplasm and produces a net gain of 2 ATP and 2 NADH per glucose molecule.
• In the presence of oxygen, pyruvate is converted into acetyl-CoA, which enters the Krebs cycle.
• Remember: Glycolysis → Pyruvate → Acetyl-CoA → Krebs cycle → Electron transport chain.

Last verified on 25-10-2026

Explanation

• The pituitary gland releases follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which regulate ovarian function.
• FSH stimulates the growth and development of ovarian follicles, while LH triggers ovulation and supports the formation of the corpus luteum.
• The ovaries produce estrogen and progesterone, which regulate the menstrual cycle and help prepare the uterus for pregnancy.

Last verified on 25-10-2026

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