Biology: CUET Mock Test - 5 - CUET MCQ

Thomas Malthus is the author of the book Principles of population. According to him, the population grows geometrically whereas food grows only arithmetically. Charles Darwin was inspired by this theory.

Brassica crops are the most suitable location for keeping beehives. This is because Brassica plants, such as mustard, produce large amounts of nectar, which bees can use to make honey. The presence of beehives near Brassica crops not only aids in the production of honey but also enhances the pollination of these crops, leading to better yields.

Key Points

• Brassica crops such as mustard are highly beneficial for beekeeping due to their high nectar production.
• The placement of beehives near these crops can significantly improve their pollination and, subsequently, crop yield.

Additional Information

• Potato and Ginger crops are less suitable for beekeeping as they do not produce as much nectar as Brassica crops.
• While Sugarcane can produce a significant amount of nectar, its tall structure can make it difficult for bees to access compared to the open flowers of Brassica.
• Choosing the right location for beehives is crucial for both the health of the bees and the productivity of the crop.

Key Points

• The correct sequence for the steps of 'Plant Breeding' is (C) Collection of genetic variability, (D) Evaluation and selection of parents, (B) Cross hybridisation among the selected parents, (A) Selection and testing of superior recombinants. This corresponds to option 2.

Additional Information

• Option 1: Incorrect because it does not follow the logical sequence of plant breeding. The first step in plant breeding cannot be the selection and testing of superior recombinants without first collecting genetic variability and evaluating parents.
• Option 3: Incorrect as it suggests starting with cross hybridisation before the collection of genetic variability and evaluation of parents, which is not the standard procedure in plant breeding.
• Option 4: Incorrect because it suggests starting the process with the evaluation and selection of parents without first collecting genetic variability, which is essential for a successful breeding program.
• The process of plant breeding begins with the collection of genetic variability to ensure a wide range of genes are available for breeding. Following this, parents are evaluated and selected based on desirable traits. Cross hybridisation among selected parents then takes place to combine these traits. Finally, superior recombinants are selected and tested, leading to the development of improved plant varieties.

The correct option is 'A - III, B - IV, C - I, D - II'.

Key Points

• Wheat is matched with Himgiri (A - III).
  • Himgiri is a variety of wheat known for its resistance to disease and adaptability to various growing conditions. It was developed to provide a stable yield under challenging environmental conditions.
• Brassica is matched with Pusa Shubhra (B - IV).
  • Pusa Shubhra is a variety of Brassica, which includes crops like mustard and canola. This variety is appreciated for its high oil content and resistance to common diseases, making it a valuable option for farmers.
• Cauliflower is matched with Pusa Swarnim (C - I).
  • Pusa Swarnim, also known as Pusa Golden, is a variety of cauliflower that is known for its early maturity and high yield. It produces attractive, golden-yellow colored heads that are rich in beta-carotene.
• Cowpea is matched with Pusa Komal (D - II).
  • Pusa Komal is a variety of cowpea developed for its superior yield and quality. It is known for producing tender, flavorful pods that are highly appreciated in culinary applications.

Therefore, the correct pairing is:
A - III: Wheat - Himgiri
B - IV: Brassica - Pusa Shubhra
C - I: Cauliflower - Pusa Swarnim
D - II: Cowpea - Pusa Komal

Key Points

• Propionibacterium sharmanii is used in the production of Swiss cheese, where it plays a crucial role in developing the distinctive holes and flavor.

Additional Information

• Roquefort cheese is made using Penicillium roqueforti, a fungus, not Propionibacterium sharmanii.
• Bread is primarily made using yeast (Saccharomyces cerevisiae) for fermentation, not Propionibacterium sharmanii.
• Toddy, an alcoholic beverage, is produced through the fermentation of sap from palm trees, involving yeasts and not Propionibacterium sharmanii.

Streptokinase is used as a 'clot buster'.

Key Points

• Streptokinase is an enzyme that helps dissolve blood clots. It is used to treat conditions such as acute myocardial infarction (heart attack) by breaking down the blood clots blocking the flow of blood to the heart.

Additional Information

• Cyclosporin-A is incorrect because it is an immunosuppressant drug used primarily after organ transplants to reduce the activity of the patient's immune system.
• Statins are incorrect as they are a class of drugs used to lower cholesterol levels in the blood, which can reduce the risk of heart disease and stroke.
• Penicillin is incorrect because it is an antibiotic used to treat bacterial infections, not blood clots.

Concept:

• Cancer is a major cause of death around the world.
• It is caused due to the breakdown of regulatory mechanisms that control the growth and differentiation of cells.
• Normal cells are able to inhibit their uncontrolled growth on contact with other cells.
• This property, called contact inhibition, is absent in cancer cells.
• Thus, the cancer cells show uncontrolled growth.

Important Points

• The uncontrolled growth of cells may give rise to 2 types of tumors:

1. Benign -
   • These remain confined to one location and do not spread to other parts.
   • Thus they cause less damage to the body.
2. Malignant -
   • This is usually a mass of proliferating cells called neoplastic or tumor cells.
   • These cells grow rapidly, invade other tissues and damage them.
   • They compete with the normal cells for vital nutrients and starve them out.
   • Cells may get sloughed off from these tumors to spread to distant sites.

• Metastasis - It is the process by which malignant cells spread to distant sites through blood and start new tumors there.

Additional InformationCauses of Cancer:

• The transformation of normal cells into cancer cells is caused by carcinogens like:
  • Physical - Ionizing radiations like X-rays and gamma rays, and non-ionizing radiations like UV rays.
  • Chemical - Chemical carcinogens of tobacco smoke that cause lung cancer.
  • Biological - Oncogenic viruses carry viral oncogenes that may cause cancer.
• Even normal cells may contain several cellular oncogenes or proto-oncogenes that may get activated by carcinogenic agents.

Treatment of Cancer:

• Radiation therapy - The cancer cells are irradiated lethally, without affecting the surrounding normal cells.
• Chemotherapy - Chemotherapeutic drugs are used to kill the cancer cells, but these have several side effects like loss of hair and anaemia.
• Immunotherapy - Patients are given biological response modifiers like α-interferons to activate the immune system, which can then destroy the cancer cells.
• Surgery - Certain tumors may be removed surgically.

Concept:

• Assisted reproductive technologies or ART refers to the special techniques that are used to deal with infertility.
• The cause of infertility may be - physical, congenital, immunological, psychological, diseases or drugs.
• Specialized infertility clinics help in diagnosis and corrective treatments of couples to enable them in conceiving.
• Sometimes, medical assisted procedures are required for a couple to bear children.
• These ART procedures aim to resolve the specific issue that is restricting pregnancy.

Important Points

• GIFT stands for Gamete intra-fallopian transfer, which one of the ART procedures to help with infertility issues.
• It involves the transfer of ovum into the fallopian tube of the female.
• The ovum is collected from a female donor.
• The ovum is transferred to the fallopian tube as that is where fertilization takes place.
• It is effective for a female:
  • who cannot produce a gamete (ovum), but
  • who can provide a suitable environment for fertilization, and
  • who can retain the fertilized zygote or embryo inside the uterus.

Therefore, GIFT cannot be used for females who cannot provide suitable environment for fertilization and also cannot retain the embryo inside uterus.

Additional InformationSome other ART methods -

• ZIFT -
  • Zygote intra-fallopian transfer is the transfer of the embryo, with less than 8 blastomeres, into the fallopian tube.
  • This is performed after in-vitro fertilization of sperm and ovum.
  • The zygote is formed under simulated conditions in the laboratory (test tube).
  • It is effective for a female who cannot provide suitable environment for fertilization, but can retain the zygote in the uterus.
• IUT -
  • Intra-uterine transfer is the transfer of embryo with more than 8 blastomeres into the uterus, where implantation takes place.
  • This is also an important part of IVF.
  • The ZIFT and IUT are types of embryo transfer techniques.
  • This method is also applicable for females who cannot provide suitable environment for fertilization, but can retain the zygote in the uterus.
• ICSI -
  • Intra-cytoplasmic sperm injection is a method by which the sperm is directly injected into the ovum.
  • It is a specialized procedure to form an embryo in-vitro.
  • It is effective where the male sperm is unable to fertilize the ovum normally due to low motility, etc.

The correct match will be:

The correct answer is a-3, b-1, c-4, d-2.

Important Points

Population Interactions

• ​It is obvious that in nature, animals, plants and microbes do not and cannot live in isolation but interact in various ways to form a biological community.
• Interspecific interactions arise from the interaction of populations of two different species.
• They could be beneficial, detrimental or neutral (neither harm nor benefit) to one of the species or both.
• Assigning a ‘+’ sign for beneficial interaction, ‘-’ sign for detrimental and 0 for neutral interaction, let us look at all the possible outcomes of interspecific interactions

Key Points

• Mutualism -
  • Example - Lichens represent an intimate mutualistic relationship between a fungus and photosynthesising algae or cyanobacteria. Similarly, the mycorrhizae are associations between fungi and the roots of higher plants. The fungi help the plant in the absorption of essential nutrients from the soil while the plant in turn provides the fungi with energy-yielding carbohydrates.
• Competition -
  • Example - The Abingdon tortoise in Galapagos Islands became extinct within a decade after goats were introduced on the island, apparently due to the greater browsing efficiency of the goats.
• Parasitism and Predation -
  • Example - The prickly pear cactus introduced into Australia in the early 1920s caused havoc by spreading rapidly into millions of hectares of rangeland. Finally, the invasive cactus was brought under control only after a cactus-feeding predator (a moth) from its natural habitat was introduced into the country.
• Commensalism -
  • Examples - An orchid growing as an epiphyte on a mango branch, and barnacles growing on the back of a whale benefit while neither the mango tree nor the whale derives any apparent benefit. The cattle egret and grazing cattle in close association, a sight you are most likely to catch if you live in farmed rural areas, is a classic example of commensalism.
• Amensalism -
  • Example - Very common example of day to day life in rural areas, When cattle trample on grass, the grass is crushed it is not beneficial for the cattle but it harms grass.

The correct answer is Dead organic matter.

• Detritus food chain is the type of food chain that starts with dead organic matter.

Two type of food chains are found in nature-

1. Grazing Food Chain -
   • The consumers starts with the food chain, utilising the plant as their food, constitute the grazing food chain.
2. Detritus Food Chain -
   • It starts from dead organic matter of decaying animals and plant bodies consumed by the microorganisms and then to detritus feeding organism called detritivores or decomposers and to other predators.

Key Points

• This dead organic matter gets decomposed by microorganisms.
• The organisms which feed on dead organic matter are known as detritivores as well as decomposers which in turn are eaten by the predators.
• Example-
  • Dead organic wastes → Microorganisms → Decomposers
• In this representation, the food chain starts with the dead organic wastes.
• These wastes are consumed by microorganisms.
• These microorganisms are consumed by other detritivore organisms like snails, earthworms, etc.

Allele frequencies does not vary from species to species. In a population, the frequency always remains fixed or constant according to Hardy Weinberg principle. The alleles and total genes in any population remain constant and hence stable.

Homo habilis was also known as tool maker or handy man. It was the first man who made tools of stones for hunting animals. They lived in caves.

During the paralytic stage, motor nerves are affected resulting in atrophy of muscles, generally of arms and legs but may affect those of diaphragm, larynx and pharynx. So, Motor Pathway is affected during the paralysis of muscles.

Fc region of an antibody is also called as a Fragment of Crystallization. It is responsible for the effector function. It is also called a constant region. It determines the isotype of an immunoglobulin.

The two key concepts of Darwin’s theory of evolution was branching descent and natural selection. Nature selects the fittest species. Adaptive ability is inherited and has a genetic basis. So, they were the two major concepts.

According to Hardy Weinberg principle, the total sum of all the frequencies of the allele is one. It shows that the gene pool remains the same or constant, i.e. one. Hence, it can be also termed as genetic equilibrium.

They had a cranial capacity of 650-800 c.c. They were the first human being like and had complete erect posture similar to them. They had the knowledge to create tools of stones to hunt.

Poliovirus generally affects the Motor Pathway of the neurons. It causes atrophy of muscles which affect the voluntary muscles of limbs and resulting in deformities. But, if the muscles of Diaphragm, Larynx and Pharynx are affected, it is always fatal.

Each antibody molecule has four peptide chains, two long chains called heavy or H chain each of molecular weight 50,000 Da and two short chains called light or L chains each of approximate molecular weight 25,000 Da.

Lamarck was a French naturalist born in 1744. He was famous for his book Philosophie Zoologique in 1809. He came up with the theory of inheritance of acquired characters.

The Hardy Weinberg equation is p² + 2pq + q² = 1. Here, p² denotes the allele of AA and q² denotes the allele aa. This shows that p, q, and A, a are related in multiplication. So, 2pq represent Aa.

On 27 March 2014, the World Health Organisation declared India a polio-free country. Polio eradication programme began internationally in 1988. It was initiated in India in 1995.

Fab region of an antibody is also called a variable region. The Fab portion is so called because it is the fragment of the molecule which is antigen binding or a paratope.

According to Lamarck, the evolution of life forms had occurred but driven by use and disuse of organs. It was among Lamarck’s basic concepts. Using an organ continuously increases its development whereas disuse of it results in its degeneration.

Individual frequencies can be represented as p and q. But for a diploid organism, p and q explain the frequency of allele A and allele a. p² represents AA whereas q² represent aa.

Homo erectus were known as the direct ancestors of humans. It had many similarities to modern man. Their face, skull structure, and posture were the same.

Flavivirus group causes Dengue and Yellow fever. This virus spreads through ticks and mosquitoes. Aedes aegypti mosquito spreads dengue fever, while Aedes and Haemagogus mosquitoes act as vectors for yellow fever.

An ovule is an integumented megasporangium found in spermatophytes which develops into a seed on fertilization. The cells within the megasporangium are diploid which will divide via meiosis to form 4 megaspores.

Giraffes were the main examples of Lamarck’s use and disuse theory. Giraffes continuously used their short necks to reach tall trees for leaves. So, this resulted in the elongation of their necks.