Zoology

Aneuploidy refers to a condition where the chromosome number is not an exact multiple of the haploid set, involving the loss or gain of individual chromosomes. Polyploidy involves the addition of entire sets of chromosomes, while polyteny refers to giant chromosomes formed by repeated replication without division.

Translocation is a chromosomal abnormality where a segment from one chromosome breaks off and attaches to a non-homologous chromosome. This differs from inversion, where a segment is reversed within the same chromosome, or deletion, where a segment is lost.

Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes, typically occurring in anaerobic conditions. It is a form of incomplete oxidation of glucose used by organisms like yeast and bacteria to generate energy without oxygen.

In the life cycle of Plasmodium, the sexual phase (sporogony) occurs within the mosquito, which is considered the exogenous host or definitive host. The asexual phase (schizogony) occurs within the human, the endogenous or intermediate host.

The Respiratory Quotient (RQ) is the ratio of CO2 produced to O2 consumed. An RQ greater than 1 occurs when organic acids are oxidized or when anaerobic respiration (which produces CO2 without consuming O2) occurs alongside aerobic respiration.

An increase in the number of X chromosomes (X complement), such as in Klinefelter syndrome (XXY) or Triple X syndrome (XXX), is often associated with cognitive deficits and mental retardation. While Y chromosome abnormalities exist, the X complement has a more pronounced effect on neurodevelopmental outcomes.

Edward's syndrome is caused by trisomy 18, which is the presence of an extra 18th autosomal chromosome. Down's syndrome involves chromosome 21, and Patau's syndrome (misspelled as Paton's in the options) involves chromosome 13.

Protoplasm is considered a complex colloidal system because it consists of various organic and inorganic molecules suspended in water, exhibiting properties like the Tyndall effect and sol-gel transformation. It is not a simple emulsion or a temporary suspension.

Solute potential, also known as osmotic potential, represents the effect of dissolved solutes on water potential. Adding solutes always lowers the water potential, making the solute potential value negative.

Pluripotency is the ability of a cell to differentiate into many different cell types that make up the body, but not the extra-embryonic tissues. Totipotency is the ability to differentiate into all possible cell types, including the placenta.

A polyribosome, or polysome, consists of a cluster of ribosomes held together by a strand of messenger RNA (mRNA). This structure allows for the simultaneous translation of a single mRNA molecule into multiple copies of a protein.

Paramecium caudatum is a ciliated protist that reproduces asexually by transverse binary fission and undergoes a sexual process called conjugation. This dual capability allows for both rapid population growth and genetic recombination.

Pancoast's syndrome is a set of symptoms caused by a tumor (neoplasm) located at the pulmonary apex (top of the lung). The tumor can compress nearby nerves and blood vessels, leading to shoulder pain and Horner's syndrome.

Muller's fibres (Müller glia) are specialized glial cells found in the vertebrate retina. They span the entire thickness of the retina and provide structural and metabolic support to the neurons.

Isoenzymes (or isozymes) are different forms of the same enzyme that catalyze the same chemical reaction but have different amino acid sequences and physical properties. They allow for fine-tuning of metabolism in different tissues or developmental stages.

Brain sand, or acervuli, are small calcified structures found in the pineal gland of humans and other animals. Their presence increases with age and they are often used as landmarks in radiological imaging of the brain.

Boa's point refers to a localized area of tenderness or hyperesthesia to the left of the 12th thoracic vertebra. It is a clinical sign traditionally associated with the presence of a gastric ulcer.

In most stable terrestrial ecosystems, the biomass decreases at each higher trophic level because energy is lost as heat and through metabolic processes. This results in an upright pyramid of biomass where producers have the highest total mass.

The enzyme activity responsible for forming peptide bonds, known as peptidyl transferase, is a ribozyme located in the large subunit of the ribosome. It facilitates the link between the amino acid on the tRNA in the A-site and the growing polypeptide chain.

Astigmatism is a common vision condition caused by an irregular curvature of the cornea or lens, which prevents light from focusing properly on the retina. This results in blurred or distorted vision at all distances.

Anticodons are sequences of three nucleotides in transfer RNA (tRNA) that are complementary to the codons found in messenger RNA (mRNA). They ensure that the correct amino acid is added to the polypeptide chain during translation.

Bindin is a species-specific protein found on the acrosomal process of sperm that recognizes and binds to receptors on the egg's vitelline membrane. This mechanism ensures that fertilization occurs only between gametes of the same species.

Endomitosis is a process where chromosomes replicate within a cell without the subsequent division of the nucleus or the cell itself. This leads to endopolyploidy, increasing the number of chromosome sets within a single nucleus.

According to the principles of natural selection, a gene or trait will increase in frequency within a population if it provides a reproductive or survival advantage. Such traits are 'suitably selected' by the environment, regardless of whether they are dominant or recessive.

  Stearic acid is not an essential fatty acid.