NEET Part Test - 5 - NEET MCQ

The ray just above x-axis shall after refraction at curved surface intersect x axis at (A) a distance x1 from O.

The critical angle for air-glass interface is  . the rays above the ray incident on curved surface at i = 37⁰ shall suffer TIR and need not be considered.

The ray incident as curved surface at θ= 37⁰ after refraction intersect curved surface at (B) a distance x₂ from O.

In Δ PBC

Chlorophyll a, shows higher rate of photosynthesis. Hence, it is conclude that chlorophyll a is the chief pigment associated with photosynthesis.

This option is correct. Cyt b₆-f complexes are evenly distributed in the stroma and granal thylakoids.

Photolysis of water is mainly carried out to compensate the electrons that are transferred to photosystem I by photosystem II during the non-cyclic photophosphorylation that reduce NADP⁺ into NADPH.

Most of the plants that are adapted to dry tropical regions have the C₄ pathway. e.g. Sugarcane, Maize, Sorghum,etc. These plants are known as C₄ plants. For the formation of sugars, C₄ plants undergo C₄ cycle as well as C₃ cycle or Calvin cycle. In these plants double fixation of carbon dioxide occurs.

ATP consumed in C₄ plants:

C₄ cycle - 2 ATP per CO₂ fixed

C₃ cycle - 3 ATP per CO₂ fixed 

Total - 5 ATP per CO₂ fixed

Thus, to form one molecule of glucose or to fix 6 CO₂, 6 X 5 = 30 ATP are consumed.

RuBisCO that is the most abundant enzyme in the world and is characterised by the fact that its active site can bind to both CO₂ and O₂ hence the name.

Phylurm Mollusca includes those animals which have a soft body, usually furnished with a shell. The body is divided into a head, muscular foot and visceral mass. Loligo (squid), Teredo (shipworm) and Octopus are some of its examples.

Arthropods show various body shapes with bilateral symmetry. They show incomplete metameric segmentation. They have true coelom containing haemocoel. In arthropods, blood vascular/circulatory system is of open type where blood flows in haemocoel instead of blood vessels.

A body cavity can mean any Interna space, or a series of spaces present inside body, whereas coelom or true body cavity generally refers to a large fluid-filled space (cavity) lying between the outer body wall and the inner digestive tube. In acoelomates no body cavity or coelom is present. Embryonic mesoderm remains as a solid layer, space between endoderm (gut wall) and ectoderm (body wall) is filled with mesenchyme and muscle fibres. In pseudocoelomates body space is a pseudocoelom or false coelom. In coelomates or eucoelomates body space is a true coelom enclosed by mesoderm on both sides. Aschelminthes are pseudocioelomates Molluscs and insects are coelomates while flatworms are acoelomates.

In sponges, sexes are not separate (hermaphrodite) i.e., eggs and sperms are produced by the same individuals. Sperms leave one sponge and enter another with water current to fertilize the ova (eggs) in situ. Thus, fertilization is internal.

Segmentation is division or differentiation of the body into distinct portions called segments. It is first observed phylum Annelida.

Sea anemone is not parasitic. It shows mutualism with hermit crab. Tapeworm is an endoparasite while leech and mosquito are exoparasites.

In animals like Hydra, jelly fish, star fish, the body can be divided into equal halves by any plane passing through the centre from top to bottom, thus exhibiting radial symmetry. In many vertebrates body can be divided into two equal halves by a single plane only thus exhibiting bilateral symmetry.
In the blind sac body plan the body has a single cavity with one opening to the outside. The single opening functions as both mouth for ingestion and anus for egestion. It is found in coelenterates and flatworms (Platyhelminthes).

• Animals that belong to the phylum Platyhelminthes to Chordata are all triploblastic.
• But Platyhelminthes and aschelminthes belong to pseudocoelomates.
• Annelids, arthropods, echinoderms and chordates are under eucoelomates. This means not all triploblastic animals are eucoelomates. 
• Pseudocoelomates have false coelom while eucoelomate animals only have the true coelom. 

Hence, both statement 1 and statement 2 are incorrect. 

A - Ectoderm
B - Endoderm
C - Mesoglea
D - Mesoderm
So, the correct answer is 'A - Ectoderm, B - Endoderm, C - Mesoglea, D - Mesoderm'.

Photosynthesis is an enzyme regulated anabolic process which involves the synthesis of organic compounds, inside the chlorophyll containing cells, from CO₂ and H₂O with the help of sunlight as a source of energy. Oxygen evolved during photosynthesis comes from water. The equation for photosynthesis can be summarised as follows.

Light is the visible part of electomagnetic radiations. Visible light consists of radiations having a wavelength between 390-760 nm (or 399-430nm), blue of indigo (430-470nm), blue green or blue (470-500nm), green (500-580nm), yellow (580-600nm), orange (600-650nm), orange red (650-600nm) and red (660-760nm).

Chlorophyll a is found in almost all photosynthetic plants except bacteria. It is called primary photosynthetic pigment because it performs primary reactions of photosynthesis which involve conversion of light energy into chemical energy. Other photosynthetic pigments like chlorophyll b, xanthophylls and carotenes are called accessory pigments. They absorb light energy of different wavelengths, broaden the spectrum of light absorption and hand over the energy to chlorophyll a through electron spin resonance and also protect chlorophyll a from photo-oxidation.

The chlorophyll pigments which are excited give up their electrons and to compensate for the loss of electrons, water is split to release four H⁺ ions and four electrons and O². The electrons that are lost from the PSII enter into an electron transfer chain or ETC.

• Gibberellic acid is a Terpene.
• All known gibberellins are diterpenoid acids that are synthesized by the terpenoid pathway in plastids and then modified in the endoplasmic reticulum and cytosol until they reach their biologically-active form.
• All gibberellins are derived via the ent-gibberellane skeleton, but are synthesized via ent-kaurene.

Skin and respiratory allergy problems arise in hilly areas due to allergen present in these areas. Allergen induce inflammatory reaction in the body.

AIDS is caused by Human immunodeficiency virus of member of group of virus called retrovirus. It is a type of RNA virus that inserts a copy of its genome into the DNA of a host cell that it invades, thus changing the genome of that cell.

AIDS day is celebrated on December 1 all over the world. Its aim is to create awareness about this dreaded disease.

Energy is a fundamental requirement for all living organisms to carry out their various biological processes. Within cells, energy is stored and transferred in different molecules. The molecule that primarily stores and transfers energy in living systems is called adenosine triphosphate, or ATP.

A: FAD (Flavin adenine dinucleotide) is another molecule involved in energy transfer within cells, but it is not the primary molecule for energy storage.

B: NADH (Nicotinamide adenine dinucleotide) is an important molecule in cellular respiration, which is involved in the transfer of electrons and hydrogen ions during energy production. While it plays a role in energy transfer, it is not the primary molecule for energy storage.

D: ADP (Adenosine diphosphate) is the molecule that forms when one phosphate group is removed from ATP. It is the "lower energy" form of ATP and can be converted back into ATP by adding a phosphate group. However, it is not the primary molecule for energy storage.

The two molecules of pyruvic acid (produced from one glucose molecule during glycolysis). The acetyl CoA then enters a cyclic pathway, tricarboxylic acid cycle, more commonly called as Krebs’ cycle. Thus, acetyl-CoA interconnecting between two cyclic pathways.

Acetyl CoA is a 2-carbon compound and 3-phosphoglycerate molecule enter into cyclic reactions during Calvin cycle.

Fermentation is a kind of anaerobic respiration in absence of oxygen to produce ethanol and carbon dioxide gas. Dough kept overnight in warm place becomes soft and spongy due to carbon dioxide gas released during fermentation.

Phosphofructokinase is a kinase enzyme that phosphorylates fructose-6-phosphate in glycolysis. The enzyme catalysed transfer of a phosphoryl group from ATP is an important reaction in a wide variety of biological processes.

• 10th to 17th day of menstrual cycle is called the risky period of conception as during which ovulation takes place.
• If sexual intercourse occurs during this period, there is a very high chance of fertilisation that may leads to pregnancy.

Hence, the correct option is D.
NCERT Reference: topic “POPULATION EXPLOSION AND BIRTH CONTROL” of chapter Reproductive Health of NCERT.

• Copper T is a small, T-shaped intrauterine contraceptive device (IUCD).
• The horizontal bar of which fits into the wide top of the uterus and the vertical bar extends down the uterus. It makes the uterus and fallopian tubes produce fluid that kills sperm. This fluid contains white blood cells, copper ions, enzymes, and prostaglandins.
• Copper ions, released by the IUD, is a spermicide and it kills sperm before it can fertilize the egg.

Hence, the correct option is A.
NCERT Reference: topic “POPULATION EXPLOSION AND BIRTH CONTROL” of chapter Reproductive Health of NCERT.