Excel in Your Preparation with cuet ug biology mock test 1

Right Answer Is C
Life span refers to the period from the birth of an organism to its natural death. Different types of organisms have different life spans which are not dependent on their body size. The life cycle of an organism is the sequence of changes and developments that it goes through from birth to death.
The reproductive phase is the time when an organism is sexually developed and can produce gametes, which fuse to form zygotes, which then develop into organisms. The growth period of an individual organism following birth and before reaching reproductive maturity is also referred to as the juvenile phase.

Right Answer Is C
Excluding single-celled organisms, no individual is immortal. It is because single-celled organisms divide and keep on living as their daughter cells. They reproduce asexually, producing offspring and becoming daughter cells.

Right Answer Is A
A clone is a genetically identical cell or organism to the original or parent cell from which it is derived. Clones are derived from asexual reproduction. In asexual reproduction, new individuals are produced by the division of the mother or parent cell.
This reproduction method does not involve the formation and fusion of gametes like sexual reproduction. Amphimixis is a kind of sexual reproduction in which the fusion of two different gametes takes place.

Right Answer Is B
The bilobed structure present at the free end of the stamen in the flower is known as an anther. Stamen is the male reproduction part of a typical flower.
The filament is a thread-like part of the stamen on which an anther is present. Pollen is the male gametophyte which is formed inside the anther. Stigma is the free end of the female reproductive part of the flower i.e. pistil.

Right Answer Is A
An anther is a bilobed structure attached to the free terminal of the stamen. It has microsporangia in which pollen grains are produced. Microsporangia are enveloped by different cellular layers in an anther. A typical angiosperm anther has four microsporangia in it.

Right Answer Is D
Microsporangium is a cellular mass present in the anther. Cells of microsporangia develop to form microspores which further mature into pollen grains.
Microsporangia are enveloped by different cellular layers which are the tapetum, middle layers, endothecium and epidermis. Tapetum is the innermost nutritive layer of microsporangium whereas the epidermis is the outermost layer of the anther.

Right Answer Is D
The line of dehiscence is the lengthwise suture of the anther. It is a longitudinal groove present in an anther from where mature pollen grains are released in the air.

Right Answer Is B
Reproductive organs which are responsible for producing gametes, as well as sex hormones in males and females, are known as primary reproductive organs. For example, testes are the primary reproductive organs of human males whereas ovaries are the primary reproductive organs of human females.

Right Answer Is D
A sex hormone is a hormone that is produced and released by the gonads. It is responsible for the control of sexual functions like the regulation of the reproductive cycle and the development of accessory reproductive organs. Estrogen and progesterone are the sex hormones produced in human females. However, testosterone is the male sex hormone.

Right Answer Is A
Scrotal sacs are present in human males. These are the pouch-like structures which hold their reproductive organs including the testes, epididymis and lower part of the spermatic cord. Scrotal sacs are connected to the abdominal cavity via the inguinal canal.
However, the vas deferens is a coiled tube which carries the sperm out of the testes. A small tube between the testes and vas deferens where the sperms are stored and get matured is known as epididymis. Seminal vesicles are a pair of glands present in the male’s reproductive system which produce fluids that form semen.

Right Answer Is D
Amniocentesis is the process of detecting the chromosomal pattern of the fetus by taking amniotic fluid. Chorionic villus sampling is a prenatal test that involves removing a chorionic villi sample from the placenta for testing.
Nuchal translucency is the process of getting a sonographic appearance of fluid collected under the skin behind the foetal neck. An ultrasound is a type of imaging test that employs sound waves to generate an image of internal organs and tissues.

Right Answer Is A
Amniocentesis is a medical practice used to diagnose chromosomal abnormalities during pregnancy, as well as to determine sex. In this procedure, a thin needle is introduced into the pregnant woman’s abdomen to collect amniotic fluid.
This fluid is used to get the chromosomal pattern of the fetus. Thus, only chromosomal aberrations like Down’s syndrome, haemophilia, Turner’s syndrome, etc and the sex of the fetus can be analyzed by this process. It does not tell about communicable diseases like cholera.

Right Answer Is A
A population explosion is a spontaneous increase in the number of people in a specific area at a specific time. It is a major point of concern for all of us because in this situation the economy is unable to provide adequate facilities to its citizens.

Right Answer Is B
Gregor Johann Mendel is famous as the father of genetics. He experimented with garden pea hybrids to develop principles of inheritance. Thomas Hunt Morgan was known as the ‘Father of Experimental Genetics’ because of his role in identifying the mutation of a white eye in the fruit fly.
Hugo de Vries proposed a theory according to which living organisms can develop variations to their genes that significantly alter the organism. These changes are passed on to the next generation, resulting in the emergence of new species. Charles Darwin is known as the father of evolution because he gave the theory of evolution by natural selection.

Right Answer Is A
Gregor Mendel selected the garden pea plant (Pisum sativum) for experimentation while studying principles of inheritance.

Right Answer Is B
Types of gametes produced by the organism = 2n, where n is the number of loci for which the organism is heterozygous. The given diploid organism is heterozygous for two loci, thus, n=2 resulting in 4 different types of gametes. (2n = 22 =4)

Right Answer Is D
Mendel selected seven characters of the pea plant each with two different traits. These characters were: Colour of the seed (green or yellow) The shape of the seed (round or wrinkled) Colour of the pod (green or yellow) The shape of the pod (constricted or inflated) Size of the plant (tall or dwarf) Position of flowers (axial or terminal) Colour of flower (purple or white)

Right Answer Is C
DNA (Deoxyribose nucleic acid) is made of monomers called nucleotides. Nucleotide pairs are stacked on one another to form a double helix of DNA. Thus, the length of the DNA segment depends on the number of nucleotides present in it.
A nucleotide is composed of a sugar molecule, a nitrogenous base and a phosphate group. However, in a nucleoside, the phosphate group is absent.

Right Answer Is A
A nucleotide is composed of a sugar molecule, a nitrogenous base and a phosphate group. The nitrogenous base is linked with the sugar residue by an N-glycosidic bond.

Right Answer Is A
A nitrogenous base combines with a sugar residue and a phosphate group to form a nucleotide.

Right Answer Is B
Aristotle was the one who stated the theory of spontaneous generation. According to this theory, life can arise from non-living things only. He proposed this theory after he saw a sudden emergence of organisms like rats and flies within rotting meat and other decomposing organic things.

Right Answer Is D
Fossils are the paleontological evidence for evolution. These are the traces or remnants of any organism that existed in the geological past. Generally, the hard parts of organisms like bones, teeth, shells, etc become fossilised, but in some cases, the entire organism is preserved.

Right Answer Is D
The natural section is the process by which organisms that are better adapted to their surroundings survive and produce more offspring. Peppered moths and Galapagos finches are two examples of natural selection.
However, plant breeding programmes are examples of artificial selection because in these programmes better traits of plants are selected by man and then their breeding is done.

Right Answer Is A
Hippocrates is known as the father of medicine. Gregor Mendel is famous as the father of genetics whereas Aristotle is known as the father of biology. However, Theophrastus is famous as the father of botany.

Right Answer Is B
Cancer is the most lethal non-infectious disease. AIDS (Acquired immune deficiency syndrome) is an infectious lethal disease. Diabetes is the result of a rise in blood sugar levels. It can lethal in the worst condition. Goitre disease results in enlargement of the thyroid gland and it is not dangerous.

Right Answer Is D
Pathogenic biological agents are organisms which can cause diseases. Most microbes are pathogenic biological agents which include bacteria, viruses, fungi, etc.

Right Answer Is C
Sericulture refers to the domestication of silkworms to obtain silk. Apiculture and pisciculture are the domestication of honeybees and fishes, respectively. Horticulture is an agricultural practice of culturing garden plants, fruits, vegetables and ornamental plants.

Right Answer Is D
The percentage fat content in chicken, duck, mutton and beef is 20%, 23%, 19% and 30% respectively. So, beef has a maximum fat content as compared the other types of animal meats.

Right Answer Is D
Honey bees do three types of dances which are round dance, sickle dance and wiggle dance. The round dance of the honey bee depicts that the food source is present at a distance of 50 meters.

Right Answer Is C
Lactic acid bacteria (LAB) are microorganisms that ferment carbohydrates to make lactic acid and are broadly used in the fermented food industry. These bacteria are basically used to prepare curd from milk.

Right Answer Is A
The yeast called Saccharomyces cerevisiae is used to produce ethanol by fermenting malted cereals and fruit juices. Due to its fermenting activity, Saccharomyces cerevisiae is commonly known as brewer’s yeast.

Right Answer Is C
Fermentation is a metabolic activity that involves the action of enzymes to produce chemical changes in organic substances. Molecules like glucose are broken down anaerobically, as a result, carbon dioxide is produced which creates puffiness in the fermented dough.

Right Answer Is B
A restriction enzyme is a bacterial protein that cleaves DNA segments at sequence-specific sites, resulting in DNA fragments. Smith and Nathan discovered these restriction enzymes. Alexander Flemming discovered penicillin antibiotic from Penicillium mould.
Stanley Cohen as well as Herbert Boyer were the first scientists to successfully transplant genes from one living organism to another, paving the way for genetic engineering.

Right Answer Is D
Bacteria use endonucleases to protect themselves from viruses by fragmenting their DNA. These endonuclease enzymes are produced by bacteria themselves and cleave the viral DNA at some specific sites.

Right Answer Is B
The process of transferring DNA fragments from an electrophoretic gel to a nitrocellulose sheet refers to southern blotting. PCR stands for Polymerase Chain Reaction and it is a method to amplify DNA to produce its million copies in very less time.
However, western blotting is used to identify and separate proteins. Electrophoresis is a technique used to separate DNA, RNA or proteins on the basis of their size and electric charge.

Right Answer Is A
Golden rice is a bioengineered crop with yellow endosperm rich in beta-carotene i.e. provitamin A. That’s why the consumption of golden rice helps in preventing blindness caused due to deficiency of vitamin-A.

Right Answer Is A
Bacillus thuringiensis (Bt) bacterial strain was used in the production of bio-insecticidal plants. Scientists choose a specific Bt toxin gene and incorporate it into the cells of a plant embryo. The Bt gene is present in all cells of the mature plant, and the insecticidal protein is expressed in the leaves. In this way, bio-insecticidal plants are produced.

Right Answer Is B
Bt-toxin affects the midgut of insect larvae to kill them. The Bt toxin dissolves and becomes active in the high pH of the insect’s midgut. Toxins then damage their gut cells, puncturing the lining.

Right Answer Is B
The biosphere refers to all living organisms present on earth which interact with the physical environment. The hydrosphere is the total mass of water existing on, beneath, and above the earth’s surface.
An ecosystem is made up of all the organisms and the physical surroundings in which they live. A habitat is a plant’s, animal’s, or other organism’s natural home or environment which provides food, water, shelter, and space to them.

Right Answer Is B
Allen’s rule is an ecogeographical rule that says that animals of the same species living in colder climates possess shorter limbs, ears, and other appendages as compared to that of warmer climates.

Right Answer Is C
An ecological niche refers to the physical position and functional role of a species within the community. A habitat is an organism’s natural home or environment which provides food, water, shelter, and space to it. A tropical level is the position or level of a species in a food chain or food web.

Right Answer Is A
Agroecosystem refers to the ecosystems that support the production systems to grow food crops. It is the largest ecosystem created by man.

Right Answer Is B
The production rate of organic components by producers per unit time per unit area refers to gross primary productivity (GPP). Net primary productivity (NPP) refers to the rate of storage of organic compounds that are not used for plant respiration. As a result, NPP = GPP – plant respiration. It is the total amount of biomass available to consumers.

Right Answer Is C
Stratification represents a distribution of different species vertically occupying different levels. It is the vertical layering of vegetation in a habitat. It primarily categorises vegetation layers based on their different heights.
The amount of nutrients such as calcium, nitrogen, and phosphorous found in the ecosystem’s soil is referred to as the standing state. The amount of total biomass available in an ecosystem is referred to as the standing crop. However, standing quality refers to the total number of living organisms present in an area at a particular time period.

Right Answer Is A
Alpha diversity refers to the diversity of organisms within the community. For example, the diversity of species within a grassland area or forest.

Right Answer Is B
Beta diversity represents the diversity between two communities. For example, the diversity of species between two different forests.

Right Answer Is A
The percentage of species diversity of plants on earth is 22% which is much less than that of animals (72%).

Right Answer Is A
In 1986, Environment (Protection) Act was passed by the Indian government to protect and improve the quality of our environment.

Right Answer Is C
The ozone layer is a gaseous layer which is responsible for the absorption of harmful UV radiations. It is present in the stratosphere layer of the atmosphere.

Right Answer Is C
The total land under Indian forest, as well as tree cover, is 80.9 million hectares in 2021, accounting for 24.62 per cent of the geographic region of the country.