Biology Test 373

The correct answer is A-III, B-I, C-IV, D-II

• A. Tidal Volume (TV) - III: The volume of air exchanged in a normal breath

• Tidal Volume (TV) is the amount of air that is inhaled or exhaled during a normal breath under resting conditions.

• B. Residual Volume (RV) - I: The volume of air that remains in the lungs after a maximal expiration

• Residual Volume (RV) is the amount of air that remains in the lungs after a person has exhaled as forcefully as possible. This air cannot be expelled and helps to keep the lungs inflated.

• C. Vital Capacity (VC) - IV: The maximum volume of air exhaled after a maximal inhalation

• Vital Capacity (VC) is the total amount of air that can be exhaled after a maximal inhalation. It is a measure of the maximum amount of air the lungs can expel.

• D. Inspiratory Capacity (IC) - II: The maximum volume of air that can be inhaled after a normal expiration

• Inspiratory Capacity (IC) is the total amount of air that can be inhaled after a normal expiration. It is the sum of the Tidal Volume and the Inspiratory Reserve Volume.

The correct answer is Both A and R are true, and R is the correct explanation of A.

Explanation:

• Class – Chondrichthyes are marine animals with streamlined body and have cartilaginous endoskeleton
• Mouth is located ventrally.
• Notochord is persistent throughout life.
• Gill slits are separate and without operculum (gill cover). The skin is tough, containing minute placoid scales.
• Teeth are modified placoid scales which are backwardly directed.
• Their jaws are very powerful.
• These animals are predaceous.
• Due to the absence of air bladder, they have to swim constantly to avoid sinking.

The correct answer is Nucleus, cytoplasm

Explanation:

• During cell division, the process starts with the division of the nucleus, known as mitosis or meiosis, depending on the type of cell division.
• Mitosis involves the segregation of duplicated chromosomes into two identical sets, whereas meiosis results in four non-identical daughter cells, each with half the chromosome number of the original cell.
• After the nuclear division is completed, the cell undergoes cytokinesis, which is the division of the cytoplasm. This results in the formation of two separate daughter cells.

The correct answer is  "Physalia".

Key Points

• Physalia  also known as the  Portuguese   man-of-war , is a marine hydrozoan found in the  Atlantic Ocean  and the  Indian Ocean .
• It is considered to be the same species as the  Pacific man of war  or blue bottle, which is found mainly in the  Pacific Ocean.
• The  Portuguese man of war  is the only species in the genus Physalia, which in turn is the only genus in the family  Physaliidae.
• The Portuguese man of war is a conspicuous member of the neuston, the community of organisms that live on the ocean surface.
• It has several  venomous  microscopic  nematocysts  which supply a painful sting effectively sufficient to kill fish and has been regarded to from time to time kill humans.
• Although it superficially resembles a jellyfish, the Portuguese man of war is in fact a  siphonophore.
• Like all siphonophores, it's far a colonial organism, made of many smaller devices known as  zooids.
• All zooids in a colony are genetically identical but fulfil specialized functions such as  feeding  and  reproduction , and collectively permit the colony to function as an unmarried individual.

The Correct Answer is Ribosomes.

Key Points

• Ribosomes are macromolecular machines, found within all living cells, which perform biological protein synthesis.
• Ribosomes consist of two major components: the small and large ribosomal subunits. Each sub-unit consists of one or more ribosomal RNA (rRNA) molecules and many ribosomal proteins (RPs or r-proteins).
• Ribosomes were first observed in the mid-1950s by Romanian-American cell biologist George Emil Palade, using an electron microscope, as dense particles or granules. The term ' ribosome ' was proposed by scientist Richard B. Roberts at the end of the 1950s.

The correct answer is A- Sporophyte B- Gametophyte

Explanation:

• Funaria exhibits gametophytic (n) as well as sporophytic (2n) generation in its life cycle.
• The gametophytic generation is represented by a short lived protonema which produces spermatozoids in the antheridium of the male shoot and egg in archegonium of female shoot. 
• The sporophyte of Funaria has an embedded foot, an elongated curved seta, and a terminal pyriform capsule. Sporophytes are nutritionally dependent on gametophytes.

The correct answer is Only 2 and 4

Explanation:

Glucocorticoids stimulate glycogenesis, lipolysis, and proteolysis, and inhibit the cellular uptake and utilization of amino acids.

• False: Glucocorticoids, such as cortisol, generally promote gluconeogenesis (the production of glucose from non-carbohydrate sources), lipolysis (breakdown of fats), and proteolysis (breakdown of proteins).
• They also inhibit the uptake of glucose by some tissues and affect amino acid metabolism.
• However, glucocorticoids generally stimulate gluconeogenesis rather than directly stimulating glycogenesis (the formation of glycogen from glucose).

Cortisol is involved in maintaining the cardiovascular system as well as the kidney functions.

• True: Cortisol plays a crucial role in maintaining various bodily functions, including cardiovascular health by regulating blood pressure and the integrity of blood vessels. It also affects kidney functions by influencing the excretion of water and electrolytes.

Addison's disease is caused by the overproduction of hormones by the adrenal cortex.

• False: Addison's disease, also known as primary adrenal insufficiency, is caused bythe underproduction of hormones, specifically cortisol and aldosterone, by the adrenal cortex.

Catecholamines stimulate the breakdown of glycogen, resulting in an increased concentration of glucose in the blood.

• True: Catecholamines, which include adrenaline (epinephrine) and noradrenaline (norepinephrine), stimulate glycogenolysis (the breakdown of glycogen into glucose) in the liver and muscles, leading to an increase in blood glucose levels.

The correct answer is Both Statement I and Statement II are correct.

Explanation:

• Statement I: Auxins induce parthenocarpy in tomatoes. This is correct because auxins can stimulate the development of fruits without the need for fertilization, leading to the formation of seedless tomatoes.
• Statement II: Auxins are widely used as herbicides. This is also correct because synthetic auxins, such as 2,4-D, are commonly used to control the growth of broadleaf weeds by causing uncontrolled and disorganized growth, ultimately leading to the death of the plant.

The correct answer is the Central nervous system is dorsal

Explanation:

The features of non-chordates among the given statements are:

• The central nervous system is ventral.
• Gill slits are absent.
• Heart is dorsal

Comparison of Chordates and Non-chordates:- 

The correct answer is Glycolysis → Krebs cycle → Electron transport chain

Explanation:

• Glycolysis: This is the first step in cellular respiration and occurs in the cytoplasm. During glycolysis, one molecule of glucose (a six-carbon sugar) is broken down into two molecules of pyruvate (a three-carbon compound). This process generates a small amount of ATP and NADH.
• Krebs Cycle (Citric Acid Cycle): The pyruvate molecules produced in glycolysis are transported into the mitochondria. Each pyruvate is converted into Acetyl-CoA, which enters the Krebs cycle. In this cycle, Acetyl-CoA is broken down into carbon dioxide, and high-energy molecules NADH and FADH₂ are produced, along with a small amount of ATP.
• Electron Transport Chain: This final step occurs in the inner mitochondrial membrane. NADH and FADH₂ generated in previous steps donate their electrons to the electron transport chain. As electrons move through the chain, a proton gradient is created across the membrane, driving the synthesis of a large amount of ATP through oxidative phosphorylation. Oxygen acts as the final electron acceptor and combines with protons to form water.

Thus, the correct sequence of events in cellular respiration is Glycolysis → Krebs cycle → Electron transport chain