SRMJEEE Biology Mock Test - 1 - JEE MCQ

• Suberin: Suberin is a fatty substance found in the cell walls of cork cells, not on the epidermis of young stems.


• Periderm: Periderm is the outer protective tissue that replaces the epidermis in older stems and roots, not found on the epidermis of young stems.


• Phellem: Phellem is a type of cork tissue that makes up the outer bark of woody stems, not present on the epidermis of young stems.


• Cuticle: The waxy coating on the epidermis of young stems is known as the cuticle. It helps reduce water loss and protects the plant from environmental stressors.

Therefore, the correct answer is option D: Cuticle.

• Genetics of color blindness: Color blindness is a sex-linked trait carried on the X chromosome. The gene responsible for color blindness is recessive, which means it is masked by the dominant gene.


• Color blind mother and normal father: The mother is color blind, which means she carries two recessive genes for color blindness (XbXb). The father is normal, carrying one dominant gene (XBY) and one recessive gene (XbY).


• Possible genotypes of the parents:
  
  
  
  • Mother (XbXb)
  
  
  • Father (XBY)
  
  
  
  


• Possible genotypes of offspring:
  
  
  
  • Sons: XbY (color blind) or XBY (normal)
  
  
  • Daughters: XbXb (color blind), XbX (carrier), or XBX (normal)
  
  
  
  


• Probability of offspring:
  
  
  
  • 50% chance of having color blind sons
  
  
  • 50% chance of having normal sons
  
  
  • 50% chance of having color blind daughters
  
  
  • 50% chance of having carrier daughters
  
  
  
  


• Conclusion: Therefore, the most likely outcome is that the couple will have color blind sons and normal/carrier daughters.

• Type O+ blood: Abhishek has type O+ blood, which means he has O blood type (lacking A and B antigens) and Rh positive blood.


• No A agglutinogens: Since Abhishek has type O blood, he does not have A antigens (agglutinogens).


• Presence of Rh agglutinogens: Abhishek has Rh positive blood, which means he does have Rh agglutinogens.


• Conclusion: Therefore, the statement "He has no A agglutinogens" is true for Abhishek with type O+ blood.

• Purpose: Amniocentesis is a prenatal test used to determine if a fetus has certain genetic conditions or birth defects.


• Procedure: During the procedure, a small amount of amniotic fluid is extracted from the amniotic sac surrounding the fetus using a thin needle inserted through the mother's abdomen.


• Embryo Health: The main purpose of amniocentesis is to evaluate the health of the embryo and detect any genetic abnormalities or chromosomal disorders.


• Risk Assessment: By analyzing the cells present in the amniotic fluid, doctors can assess the risk of conditions such as Down syndrome, cystic fibrosis, and neural tube defects.


• Accuracy: Amniocentesis is highly accurate in identifying genetic conditions, providing valuable information to parents and healthcare providers.

Amylase is an enzyme that helps digest carbohydrates. It is made in the pancreas and the glands that make saliva. When the pancreasis diseased or inflamed, amylase releases into the blood. A test can be done to measure the level of this enzyme in your blood.

• Gasohol is a mixture of ethanol and petrol.

• Option A: 10% ethanol and 90% petrol


• Option B: 20% ethanol and 80% petrol


• Option C: 30% ethanol and 70% petrol


• Option D: 40% ethanol and 60% petrol

• Gasohol typically contains a lower percentage of ethanol and a higher percentage of petrol.


• Among the given options, Option A with 10% ethanol and 90% petrol aligns with the usual composition of gasohol.


• Therefore, the correct answer is Option A: 10% ethanol and 90% petrol.

Total or holoblastic cleavage - In this type the cleavage furrow bisects the entire egg. Such a cleavage may be either equal or unequal.

• Centrolecithal eggs: These eggs have yolk in the center and cytoplasm in a peripheral layer.


• Types of eggs based on yolk distribution:




• Isolecithal: Eggs with an even distribution of yolk throughout the cytoplasm.


• Microlecithal: Eggs with very little yolk present.


• Centrolecithal: Eggs with yolk in the center and cytoplasm in a peripheral layer.


• Telolecithal: Eggs with a large amount of yolk concentrated at one end.




• Importance of egg classification: Understanding the type of egg is crucial for understanding embryonic development and reproductive strategies of different species.

Chimpanzee is more closely related to man than other hominoids. It is evidenced by chromosome banding pattern, DNA extracted from sex chromosomes, autosomes and mitochondria. Molecular clock based on mitochondrial DNA are used to date recent events because this DNA mutates 5-10 times faster than nuclear DNA. Some similarities between human and chimpanzee are -  DNA matching shows human similarity with chimpanzee. There is little difference in banding pattern in chromosomes 3 and 6 in human and chimpanzee. Serum test indicate maximum homology between human and chimpanzee. 

• UGU: This codon codes for the amino acid cysteine, not the same as UGC which codes for cysteine.


• UGA: This codon is a stop codon and does not code for any amino acid.


• UAG: This codon is also a stop codon and does not code for any amino acid.


• UGG: This codon codes for the amino acid tryptophan, not the same as UGC which codes for cysteine.

Therefore, the codon UGU is the correct answer as it codes for the same amino acid as UGC, which is cysteine.

• The wobble hypothesis explains how tRNA molecules can recognize more than one codon due to flexibility in the base pairing at the third position of the codon.


• This flexibility allows for economy in tRNA molecules as fewer tRNAs are needed to decode all possible codons.

• During initiation, the small ribosomal subunit binds to the mRNA at the start codon (AUG) with the help of initiation factors.


• The initiator tRNA carrying the amino acid methionine binds to the start codon, marking the beginning of peptide chain formation.

• Termination of peptide chain occurs when a stop codon (UAA, UAG, or UGA) is reached on the mRNA.


• Release factors bind to the ribosome, causing the release of the completed polypeptide chain.

• The wobble hypothesis plays a crucial role in the economy of tRNA molecules by allowing a single tRNA to recognize multiple codons through non-standard base pairing at the third position.


• This reduces the number of tRNA molecules required for translation and ensures efficient protein synthesis.

Here, both type of traits are transmitting in a single individual. It means both are dominant at a time or codominant, e.g., blood groups of human being and roan colour in cattles.

Codominance is a condition in which two different alleles for a genetic trait, both are expressed. Codominance is a relationship between two versions of a gene. Individuals receive one version of a gene, called an allele, from each parent

Epistasis: Interaction of two separate genes

• Definition: Epistasis is a phenomenon where the effect of one gene masks or modifies the effect of another gene at a different locus.


• Interaction of two separate genes: Epistasis occurs when two different genes interact to influence a particular trait or phenotype.


• Example: One classic example of epistasis is coat color in mice. The gene for pigment production (B) interacts with another gene (C) that determines whether the pigment is deposited in the fur. If the gene C is not functional, the coat color gene B does not have an effect, resulting in an albino mouse.


• Genetic pathways: Epistasis can reveal intricate genetic pathways and interactions between genes that control complex traits.


• Study of gene interactions: Understanding epistasis is crucial in genetics research to unravel the complexities of genetic inheritance and phenotypic expression.

• Malleus: The bone attached to the inner surface of the eardrum is called the malleus. It is one of the three tiny bones in the middle ear, along with the incus and stapes.



• Function: The malleus is responsible for transmitting sound vibrations from the eardrum to the incus and then to the stapes, where they are further transmitted to the inner ear.



• Anatomy: The malleus is shaped like a hammer, with a handle (manubrium) attached to the eardrum and a head that connects to the incus.



• Importance: The malleus plays a crucial role in the process of hearing by amplifying and transmitting sound waves to the inner ear, where they are converted into electrical signals that are interpreted by the brain.



• Overall: Understanding the anatomy and function of the malleus is essential for comprehending the complex process of hearing and the role of the middle ear in this sensory function.

• Description: The Cori Cycle is a metabolic pathway in which lactic acid produced by muscles during anaerobic respiration is transported to the liver and converted back into glucose or glycogen.


• Process:
  
  
  
  • Lactic acid is produced in muscles when there is a lack of oxygen during intense exercise.
  
  
  • The lactic acid is transported via the bloodstream to the liver.
  
  
  • In the liver, lactic acid is converted to pyruvate and then to glucose through a series of reactions.
  
  
  • The newly formed glucose can either be released back into the bloodstream to be used by muscles for energy or stored in the liver as glycogen for later use.
  
  
  
  


• Role: The Cori Cycle helps to maintain blood glucose levels during times of high energy demand, such as during exercise, by recycling lactic acid produced by muscles.


• Significance: This cycle allows for the continuous production of energy in muscles, even when oxygen is limited, by converting lactic acid back into a usable form of energy (glucose).

• Function: The cerebellum is responsible for coordinating movement, including hand-eye coordination.


• Location: The cerebellum is located at the back of the brain, below the cerebrum.


• Role in Hand-Eye Coordination: The cerebellum receives information from the sensory systems, spinal cord, and other parts of the brain to coordinate voluntary movements such as reaching, grasping, and tracking objects with the eyes.


• Importance: Damage to the cerebellum can result in problems with coordination, balance, and fine motor skills, affecting hand-eye coordination as well.

• Definition: Homologous organs are organs that have similar structures but different functions, indicating common ancestry.

• Function: Wings of birds are used for flight.

• Definition: Pectoral fins of fish are the paired fins located on the sides of the fish, near the head.


• Function: Pectoral fins are used for stability and maneuvering in water.


• Homologous Relationship: Wings of birds and pectoral fins of fish are considered homologous organs because they have similar structural features, such as bones and muscles, despite serving different functions. This similarity indicates that they share a common evolutionary origin.

• Therefore, the pectoral fins of fish are the homologous organs of the wings of birds.

• Definition: Industrial wastes refer to the waste products generated by industrial activities, which often contain harmful chemicals and pollutants.


• Source: Industries release a variety of waste materials into water bodies, including heavy metals, toxins, and other pollutants.


• Quantity: Industrial wastes are one of the largest sources of water pollution globally due to the large volume of waste produced by industries.


• Impact: These pollutants can contaminate water sources, affecting aquatic life, ecosystems, and human health.


• Regulation: Many countries have regulations in place to control and monitor industrial waste disposal to reduce water pollution.

• Hyaluronidase: Hyaluronidase is an enzyme that plays a crucial role in the fertilization process by helping sperm penetrate the egg. A decrease in the secretion of hyaluronidase can lead to a decrease in sperm motility and ability to fertilize the egg, ultimately resulting in sterility.

• Luteinizing hormone (LH): LH is produced by the pituitary gland and plays a crucial role in the regulation of testosterone production in the testes. It stimulates the Leydig cells in the testes to produce testosterone.



• Follicle-stimulating hormone (FSH): FSH, also produced by the pituitary gland, works in conjunction with LH to regulate testosterone production. It stimulates the Sertoli cells in the testes, which support sperm production and testosterone synthesis.



• Oxytocin and Progesterone: While oxytocin and progesterone play important roles in other physiological processes, they do not directly regulate testosterone production.

Therefore, the correct answer is Luteinizing hormone (LH), as it is the primary hormone responsible for regulating testosterone production in the body.

• Glycolysis: Glycolysis is the metabolic pathway that converts glucose into pyruvate.


• Pyruvic Acid Formation: At the end of glycolysis, one molecule of glucose is converted into two molecules of pyruvic acid.


• Number of Molecules: Therefore, from one molecule of glucose, two molecules of pyruvic acid are formed.


• Answer: So, the correct answer is 2 (B).