Test: Biology Minor Mock Test- 2 (March 18) - NEET MCQ

• Electrons from excited chlorphyll molecule of photosystem II are accepted first by Quinone.
• Photosystem II is a photosynthetic pigment system along with some electron carriers that is located in the appressed part of the grana thylakoids.
• Photosystem II has chlorophyll a, b and carotenoids. Other components of PS II are phaeophytin, plastoquinone (PQ), cytochrome complex and blue coloured copper-containing plastocyanin.

The most abundant type of animal tissue connective tissue. It forms blood, bone cartilage, adipose. Lymph etc.

All enzymes of the TCA cycle are present in the mitochondrial matrix, except succinate dehydrogenase.
Succinate dehydrogenase is tightly bound to the inner mitochondrial membrane in eukaryotes and to the plasma membrane in prokaryotes.

• In the photorespiratory pathway, there is no synthesis of ATP or NADPH. Therefore, photorespiration is a wasteful process.
• In C₄ plants photorespiration does not occur. This is because they have a mechanism that increases the concentration of CO₂ at the enzyme site.

Astral body are formed of microtubules. Astral bodies are produced by centriole during cell division and attach with centromere of the chromosome.

Erythrocytes are also known as red blood cells that deliver oxygen to and remove carbon dioxide from tissues. Erythrocytes have a limited life span and as they age, their membranes become more fragile leading to a loss of function and swelling. This damage occurs as the fragile cells pass through narrow capillaries, which occurs in the spleen. The life span of the erythrocyte varies from 70-160 days in domestic species. The average lifespan of RBCs in human is 120 days.

The life span of WBC ranges from 6 - 20 days, depending on the type, after which they are destroyed in the lymphatic system. When immature WBCs are first released from the bone marrow into the blood, they are called bands or stabs. The life span of a circulating human neutrophil is about 5.4 days, while the life span of the monocyte is 10 - 20 hours.

Rudolf Virchow(1855) first explained that cells divided and new cells are formed .

The shapes of bacteria are bacillus (rod like), coccus (spherical), vibrio (comma shaped) and spirillum (spiral).

Fat consists of molecules of fatty acids and molecules of glycerin. Each molecule of fat contain three molecules of fatty acids and one molecule of glycerine3. 

Solution: DNA replication occurs during the S (Synthesis) phase of the cell cycle. This phase is characterized by the doubling of the DNA content in the cell, from 2C to 4C, although the chromosome number remains unchanged. This ensures that each daughter cell receives a complete set of chromosomes during cell division.

The cytoskeleton in a cell is involved in functions like mechanical support, motility, maintenance of the shape of the cell.

According to Chargaff's base pair rule, DNA from any cell of an organism should have a 1:1 ratio of pyrimidine and purine bases, that is, the total amount of purines = total amount of pyrimidines.  In this, the amount of guanine is equal to the amount of cytosine and the amount of adenine is equal to the amount of thymine. The ratio of A: T = 1 and the ratio of G: C = 1. According to Chargaff's rule, G + C / A + T ratio varies with the species but is constant for a species. 

Glucose-6-phosphate is oxidised to form lactone. NADPH is produced as a by-product of this reaction. NADP⁺ is reduced as glucose-6-phosphate is oxidised.

The Calvin cycle can be described under three stages: carboxylation, reduction and regeneration. Pathway operated in cyclic manner.

One GTP molecule is produced from one acetyl-CoA molecules. Two GTP molecules are produced from two acetyl-CoA molecules.

Alcoholic fermentation is respiration in absence of oxygen. In this, hexose molecule is converted into ethyl alcohol and CO₂, with the activity of enzyme 'zymase' produced by yeast.

Proteins human haemoglobin consists of 4 subunits. Two of these are identical toeach other. Hence, two subunits of αα type and two subunits of ββ type together constitute the human haemoglobin (Hb).

The structure of the cells varies according to their function. Therefore, the tissues are different and are broadly classified into four types –

• Epithelial tissue
• Connective tissue
• Muscular tissue
• Neural tissue.

• The group of similar or dissimilar cells that have a common origin and perform a similar function is called tissue.
• These tissues are organised in specific proportion and pattern to form an organ like stomach, lung, heart and kidney.

During the G2 phase, proteins are synthesised in preparation for mitosis while cell growth continues.

In plant cell, mitosis cell division is generally controlled by cytokinin hormone. Auxinis also required for cell division in plant.

Jan Ingenhousz's experiments with an aquatic plant showed that in bright sunlight, small bubbles containing oxygen were formed around the green parts of the plant, while in the dark, they did not. This demonstrated that sunlight is essential for the process by which plants release oxygen.

Mitochondria are double membranous structure. The inner membrane of mitochondria thrown into folds to form finger-like structureis called cristae.

• The haploid phase of life cycle occurs when the total chromosome number inside the cell is reduced to half.
• It occurs by the process of meiosis.
• Fertilization restores the diploid phase of life cycle.

• The fibres of connective tissue provide strength, elasticity and flexibility to the tissue.
• These cells also secrete modified polysaccharides, which accumulate between cells and fibres and act as a matrix.

In C₄ plants, Carbon dioxide is fixed in malic acid with the help of enzyme phosphoenel pyruvate (PEP). Malic acid is a four-carbon compound that later changes into oxaloacetic acid.

Reserve material in prokaryotic cells are stored in the cytoplasm in the form of inclusion bodies.

• There are 20 naturally occurring amino acids.
• All the amino acids except glycine are chiral. Amino acids are classified as acidic, basic or neutral based on the relative number of amino and carboxylic groups.
• Amino acids are classified as essential amino acids and non-essential based on whether they are synthesized in the body or not.

ATP is synthesized by cells (in mitochondria and chloroplasts) is named phosphorylation.