Class XII Biology Part 1 - Practice Test

During the pollen grain formation, the generative cell divides to give rise to the two male gametes. What is the ploidy of the generative cell?

Kiwi is a dioecious species. Which of the following methods can be definitely RULED OUT as a possible mode of pollination in its case?

Arun thinks that identifying the exact mRNA sequence from the protein sequence is difficult. Is he correct and why?

Crickets are insects that follow the XO type of sex determination. Which of the following statements is ALWAYS TRUE about this type of sex determination?

Oysters are generally either dark or light in colour. Dark oysters excel in dark environments, while light oysters thrive in bright environments. Intermediate-coloured oysters are disadvantaged, lacking effective camouflage in either setting. Which type of natural selection does this phenomenon exemplify?

A team of archaeologists found a fossilized skeleton of a human-like creature with a brain capacity of more than 700cc. The structure and its associated findings also show evidence that this creature could use tools for hunting. Which stage of human evolution is this creature NOT from?

Which of the following is CORRECT about the movement of DNA on an agarose gel and the reason for it?

What is the MINIMUM possibility of a dominant trait being expressed in the offspring after a test cross?

Which process is responsible for increasing the percentage of alcohol in whisky after fermentation?

What does I in the restriction enzyme named 'Hin S2 I' indicate?

Sumi says 'Gametes are not required for hybridization' and Nisha says 'The resultant plant that grows after the fusion of the cells is genetically identical to the parent plants' about somatic hybridization in plants. Who among them is/are CORRECT?

Rupal says that in marine food chains where the pyramid of biomass is inverted, the 10% rule of energy transfer is not applicable. Is she CORRECT and why?

Assertion (A): The coconut endosperm is multinucleate throughout its development. Reason (R): Some endosperms undergo free nuclear division without the formation of distinct cell boundaries.

Assertion (A): DNA ligase is not used in PCR. Reason (R): Discontinuous fragments are not formed in the amplification of DNA by PCR.

Assertion (A): To promote sustainability while minimizing waste, it is recommended to reuse needles up to two times for the same person. Reason (R): Sterilisation of needles eliminates all pathogens and ensures safety.

Assertion (A): Nuclear DNA extracted from a cell is visible to the naked eye but unstained plasmid DNA running in an agarose gel is not. Reason (R): Plasmid DNA is transparent but nuclear DNA is not.

Which hormone does the placenta produce that plays a crucial role during pregnancy?

Thalassemia is an autosomal recessive disorder. In a cross between a carrier mother and a thalassemic father, what is the genotypic ratio of offspring?

Which of the following is a reason why AIDS treatment is only partially effective?

For growing Lactobacillus (anaerobic bacterium) in a bioreactor, which component should definitely NOT be present?

In the food chain: Fallen leaf → Millipedes → Fungi → Earthworm → Soil, which step is likely to be slower?

Which cells in the seminiferous tubule are diploid?

If a woman's regular period is scheduled to start on July 19, what was the estimated date of ovulation for the previous cycle?

In ART, blastomeres with less than 8 cells are transferred to which destination?

Which phenomenon can cause Hardy-Weinberg equilibrium to not hold true?

Flocs reduce the pollution in water by increasing its BOD. This statement is:

What is the first step in producing human erythropoietin using recombinant DNA technology?

Using the species-area relationship S = cAz, if Antarctica has area 14 x 10⁶ km² with y-intercept 5, and regression coefficient 1, what is the species richness?

What is the advantage of having two 'ori' sequences in the same cloning vector?

In predator-prey population dynamics, what is the likely cause for oscillating population patterns?