Biology Test - 41

Under normal aerobic conditions, pyruvic acid is oxidized to CO₂ and Water in cellular organelles, known asMitochondria.

In second stage of aerobic oxidation, pyruvic acid formed in glycolysis is transported to mitochondria, where it is oxidized to carbon dioxide and water. 34 out of 36 ATPs are also released in this process, giving mitochondria the name, ‘Power House of the Cell’.

Golgi apparatus package proteins into membrane bound vesicles inside the cell before they are sent to their destination.

Ribosomes are responsible for protein synthesis.

Chloroplast is responsible for conducting photosynthesis.

Arthropoda is the largest phylum of Animalia.

An arthropod is an invertebrate animal having an exoskeleton, a segmented body, and paired jointed appendages.

• It is considered the largest phylum in the animal kingdom with an estimated 85 per cent of known species included in this phylum.
• The largest phylum in the animal kingdom includes such familiar forms as lobsters, crabs, spiders, mites, insects, centipedes, and millipedes.
• They adapted to solve the problems of support, stability, desiccation, and respiration.
• The extant members of this kingdom are typically small, but extinct arthropods such as the Eurypterids grew to enormous sizes.
• The arthropods were one of the earliest groups of animals to evolve, and they survived all the major mass extinctions, which wiped out most other life forms.

Mollusca:

• Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda.
• The members are known as molluscs or mollusks.
• Around 85,000 extant species of molluscs are recognized.
• The number of fossil species is estimated between 60,000 and 100,000 additional species.

Ctenophora:

• Ctenophora comprise a phylum of invertebrate animals that live in marine waters worldwide.
• They are notable for the groups of cilia they use for swimming, and they are the largest animals to swim with the help of cilia.
• Depending on the species, adult ctenophores range from a few millimetres to 1.5 m in size.

Platyhelminthes:

• They have a dorsoventrally flattened body, hence are called flatworms.
• These are mostly endoparasites found in animals including human beings.
• Flatworms are bilaterally symmetrical, triploblastic and acoelomate animals with organ level of organisation.
• Examples: Taenia (Tapeworm), Fasciola (Liver fluke).

Human teeth are set in sockets and have all of the characteristics, that's why their dentition refers to as thecodont, heterodont and diphyodont.

Southern blotting is the attachment of probes to DNA fragments. Southern blotting is a laboratory technique used to detect a specific DNA sequence in a blood or tissue sample. A restriction enzyme is used to cut a sample of DNA into fragments that are separated using gel electrophoresis. The DNA fragments are transferred out of the gel to the surface of a membrane.

SNAREhypothesis explain vesicle fusion.

Vesicle fusion is the merging of a vesicle with other vesicles or a part of a cell membrane. In the latter case, it is the end stage of secretion from secretory vesicles, where their contents are expelled from the cell through exocytosis. Vesicles can also fuse with other target cell compartments, such as a lysosome. Exocytosis occurs when secretory vesicles transiently dock and fuse at the base of cup-shaped structures at the cell plasma membrane called porosome, the universal secretory machinery in cells.

Earth's original atmosphere was probably just hydrogen and helium because these were the main gases in the dusty, gassy disk around the Sun from which the planets formed. The Earth and its atmosphere were very hot. Molecules of hydrogen and helium move really fast, especially when warm. Therefore, statement (A) is correct.

Earth's second atmosphere was formed from the outgassing of volcanoes and was composed mainly of water vapour (80%), carbon dioxide (10%), and nitrogen (5%). Therefore, statement (B) is correct.

The atmosphere is composed of a mix of several different gases in differing amounts. The permanent gases whose percentages do not change from day to day are nitrogen, oxygen and argon. Nitrogen accounts for 78% of the atmosphere, oxygen 21% and argon 0.9%. Gases like carbon dioxide, nitrous oxides, methane, and ozone are trace gases that account for about a tenth of one per cent of the atmosphere. Water vapour is unique in that its concentration varies from 0-4% of the atmosphere depending on where you are and what time of the day it is. Therefore, statement (C) is incorrect.

The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs and is composed of a layer of mesothelium supported by a thin layer of connective tissue.

In the cell-mediated immune response, \(T\) lymphocytes divide and secrete cytokines.

Cytokines are cell-signalling molecules secreted by \(T\)-cells in cell-mediated immune response. These are often secreted by immune cells that have encountered a pathogen, thereby activating and recruiting further immune cells to increase the system's response to the pathogen.

Thromboxane \(A_{2}\)causes arterial and bronchial constriction and platelet aggregation.

When Thromboxane \(A_{2}\) binds to its receptor, there is an influx of calcium ions which directly increase contraction of smooth muscle cells. The vasoconstriction caused by Thromboxane \(A_{2}\) aids in the platelet aggregation because platelets are close to each other, which leads to greater clot formation.

Active immunity is developed in direct response to disease.

Active Immunity results when exposure to a disease organism triggers the immune system to produce antibodies to that disease. Active immunity can be acquired through natural immunity or vaccine-induced immunity.