GCET Mock - 5 (Bio)

Complementary DNA (cDNA) is produced by reverse transcription.

Cucumber is an example of Monoecious plant.
Cucumber is an example of Monoecious plant.

It is true that the rate of DNA replication is much faster in E. coli than in eukaryotes. It is also true that the length of Okazaki fragments that result from DNA Polymerase I activity are much shorter in prokaryotes than in eukaryotes. But R is not the correct explanation of A. 

Chemically the female sex hormones estradiol and progesterone are steroids.

Before ejaculation in mammals the spermatozoa are stored in epididymis.

Scion is a cutting of young stem used for grafting.

Micropyle is an opening at the lower end of the ovule.

Parasitism is more difficult to describe. However a parasite defines an organism which is in continues intimate association with other organism called host upon which it is metabolically dependent directly or indirectly. Commensalism considered as a loose association in which two animals of different species lived together without being either metabolically dependent on one or both organisms may receive some benefits from the association. Predation is a type of symbiotic association between two different organisms where one acts as predator that seizes & feeds on other organism which acts as prey. Mutualism is an association between two organisms of two different species where both organisms are benefited from the relationship. Competition is an association between organisms for resources like food, shelter and so on where both may causes harm to each other.

The trophic level of an organism is the position it occupies in the food chain. Green plants make up the first trophic level and are known as primary producers. Plants are able to convert energy from the sun into food through a process known as photosynthesis. In the second trophic level, the primary consumers - known as herbivores - are animals and insects that obtain their energy solely by eating the green plants. The third trophic level is composed of the secondary consumers, flesh-eating or carnivorous animals that feed on herbivores. At the fourth level are the tertiary consumers, carnivores that feed on other carnivores. Finally, the fifth trophic level consists of the decomposers, organisms such as fungi and bacteria that break down dead or dying matter into nutrients that can be used again.

Offset of water hyacinth, Rhizome of ginger and banana.
Offset of water hyacinth, Rhizome of ginger and banana.

Genes for antibiotic resistance are located in the plasmid.

Correct. T1 plasmid is used as cloning vector,it is used to deliver to genes of interest into plants. IT is produced by Agrobacterium Tumifaciens.

Restriction endonucleases act as molecular scissors but DNA ligases help in linking foreign DNA to plasmid.

DNA polymerase is used in PCR. It is used to produce double stranded DNA from single stranded DNA.

Herbicide resistant GM crops will remain unaffected to the herbicide used, therefore the weeds will be killed.

It is a variety of Oryza sativa  produced by genetic engineering to synthesize beta carotene, a precursor of vitamin A. This option is correct.

Amino acid sequence in protein synthesis is decided by the sequence of mRNA. 

Antisense technology is the translational control of protein synthesis which involves use of RNA which is complementry to m-RNA, inhibiting the expression of genes.

This recruitment process is known as inflammation.

Less than 60%

Darwin stated that adaptations enable one species to produce more offspring by natural selection. 

Analogous organs are the organs which have the same function but are of different origin. Wings of birds and bats are analogous organs.

 HIV that causes AIDS, first starts destroying helper T-lymphocytes.

Algae do not cause diseases in plants.

Heterosis is the improved or increased function of any biological quality in a hybrid offspring. An offspring exhibits heterosis if its traits are enhanced as a result of mixing the genetic contributions of its parents.

Cells of meristematic tissue are totipotent as they composed of immature and undifferentiated cells which are either in a continuous state of division or retain the power of division.

The spores are the means of reproduction in many fungi like mosses and ferns. The growth of fungus can also be observed on moist bread surface kept undisturbed for some time.

It is advantageous to use microbial enzymes in organic synthesis than mammalian enzymes. This is because microorganisms can be made available, if needed, in much higher amounts than the animals. 

Rickets affects bones and malaria affects blood cells which may in turn damage spleen or liver.

Symbiosis is useful for both host and endosymbiont. 

LPG does not cause pollution on burning.

In maize, hybrid vigour is exploited by crossing of two inbreed parental lines. 

In S-shaped or sigmoid curve, the growth rate is very high. The birth and death rates are two major determinants of population growth. Growth rate will be high when birth rate exceeds the death rate. 

Each prey population has a greater biomass than its predator population in all food chains except in pond ecosystem. 

National park is an in situ method for biodiversity conservation. In situ conservation is on the site conservation method ex-situ conservation means conservation away from natural habitat.

A keystone species is a species whose very presence contributes to a diversity of life and whose extinction would consequently lead to the extinction of other forms of life. Keystone species help to support the ecosystem (entire community of life) of which they are a part. 

Sulphur dioxide causes acid rain.

The global ecosystem is known as biosphere.

Withdrawal of progesterone leads to menstruation.

The reproduction in phanerogams occurs by seeds. 

Biosphere Reserve: Large areas of protected land for conservation of wildlife, plant and animal resources and traditional life of tribals living in the area. 
Wildlife Sanctuary: Areas where animals are protected from any disturbance to them and their habitat.
National Park: Areas reserved for wildlife where it can freely use habitats and natural resources.

Greenhouse gases are responsible for global warming. But they cannot be eliminated as one of them is CO_{2 ,} which is essential for plants to synthesise food. CO₂ is not the most dangerous gas, it is said so just because it is present in highest concentration in the atmosphere. Otherwise, on per molecule basis, the most dangerous greenhouse gas is methane.

J-shaped chromosomes are called acrocentric. 

2 polar bodies are formed and the 2nd polar body divides again to form 2 more polar bodies , hence in the end there are 3 polar bodies .

It is about 14 days long .

Double fertilization means fusion of one male nucleus with egg nucleus and other male nucleus with polar nuclei. 

Placenta in mammalian embryo is formed by chorion. 

Turner's syndrome, 45,X, encompasses several conditions in human females, of which monosomy X (absence of an entire sex chromosome, the Barr body) is most common. It is an example of hypoploidy.

&#xA0

Megaspore mother cell undergoes meiosis. On the basis of participation of megaspore nuclei, the development of embryosac may be monosporic, bisporic of tetrasporic.

Statement (a) is correct. Endometrium is the innermost layer of uterus which is highly vascularized and rich in glands. Statement (b) is correct. Gametogenesis is the process of formation of gametes in sexual reproduction. Statement (c) is incorrect. Mitochondria provides energy for the movement of sperm.

50 parent cell divisions are necessary to produce two hundred pollen grains. 

In gamete intrafallopian transfer (GIFT)eggs and sperm are collected and injected directly into the upper regions of the oviducts, where fertilization normally takes place.

Inhibin is secreted by sertoli cells. It exerts negative feedback on the production of FSH by cells in the anterior pituitary.

In Mirabilis, red flower crossed with white flower parent, F1 is pink due to codominance of both the alleles and in F2 one red two pink and one white will be produced.

Syphilis is a bacterial infection that's typically spread through sexual contact.It most commonly begins as a painless sore, usually in the area of your genitals, rectum, or mouth.The infection spreads from person to person through contact with these sores by the skin or mucous membranes.

Probability of number of gametes produced is 2ⁿ. When n = 3, then 2 X 2 X 2 = 8 types of gametes. 

During S phase, cell will undergo DNA replication.

Snapdragon flower color: F^Rallele is for red flower colour and F^Wallele for white flower and in when both F^RF^W condition it will be pink due to codominance and in ABO blood group A and B alleles are codominant to each other. 

A fruit fly heterozygous for sex linked genes is mated with a normal female fruit fly. The male specified chromosome is likely to enter egg cells in the proportion of 1:1. 

Semi-conservative model of DNA replication was experimentally proved by Meselson and Stahl.

Statement 1 is incorrect.
BOD - Standard method for indirect measurement of the amount of organic pollution in a sample of water. Thus, high BOD means high pollution.
Statement 2 is also incorrect.
            Eutrophication - The process by which a water body acquires high concentration of nutrients, especially phosphates and nitrates. It promotes growth of algae and the decomposing organisms deplete the available oxygen in water. Thus, there is a decrease in concentration of oxygen and increase in concentration of carbon dioxide.

RNA retroviruses have special enzyme that transcribes viral RNA to DNA. 

The enzyme which helps to remove nucleotide from the end of DNA is exonuclease.

A peptide bond is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water (H2O).

In protein synthesis of prokaryotes, the initiation of polypeptide chain is always brought about by an amino acid, methionine, which is coded by AUG.

Genes required for lactose metabolism will be transcribed when inducer is present.

One turn of the helix in a B-form DNA is approximately 3.4 nm. 

The behaviour of homologous chromosomes during meiosis (their segregation) and independent assortment) and their reunion in fertilisation confirmed that the genetic material occurs in the chromosomes and formed the basis of chromosomal theory of inheritance. Which is propounded independentaly by Sutton and Boveri in 1902. A karyotype composed of two identical sets of dissimilar chromosomes is called diploid set and of single set of chromosomes is called haploid set.

If the repressor can no longer bind tryptophan, then it cannot bind the operator and transcription of the trp operon will always be on, whether tryptophan levels in the cell are high or low.

Only option 1 gives the correct match of the scientist name with its discovery.

Down's syndrome or mongolism or mongolian idiocy is caused by the trisomy on chromosome number 21. Thus, the egg possesses 24 chromosomes instead of 23 and the offspring has 47 chromosomes (45 + XY in male, 45 + XX in female). 

Neutrophils, macrophages, lymphocytes, eosinophils and basophils are the kinds of WBCs which take part in immune system. 

In humans and drosophilas, the sex determination is of XX-XY type.

 <div align="justify"