RE-NEET Botany Class 12 Questions
40 questions
How many theca are present in each lobe of a typical bilobed angiosperm anther?
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: In an experiment, Mendel observed that the F₁ progeny plants are all tall and none are dwarf. Reason R: Stem height is a contrasting trait, with tall being dominant and dwarf being recessive. In the light of the above statements, choose the most appropriate answer from the options given below:
Which of the following plant produces non-albuminous seeds?
For a person with blood group ‘O’, which of the following is not a possible combination of parents’ blood group genotypes?
Arrange the following in descending order of number of species in the Amazonian rain forest. (a) Plants (b) Birds (c) Fishes (d) Invertebrates (e) Mammals
If the diploid chromosome number of a typical angiosperm is 36, what would be the chromosome number in its endosperm?
Which of the following in female gametophyte of an angiosperm helps in guiding the pollen tube for fertilizing the eggs?
Match List-I with List-II.
Which of the following are primary consumers in a food chain?
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Abingdon tortoise in Galapagos islands became extinct within a decade after goats were introduced. Reason R: Goats were more efficient at browsing than Abingdon tortoise. In the light of the above statements, choose the most appropriate answer from the options given below:
Which of the following statements about lac-operon is correct?
Given below are two statements:
Statement I: Down's syndrome is caused by the absence of one of the X-chromosomes.
Statement II: Turner's syndrome is caused by the presence of an additional copy of the chromosomes.
In the light of the above statements, choose the correct answer from the options given below:
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: The logistic growth model of populations is considered more realistic than the exponential growth model. Reason R: Resources are finite. In the light of the above statements, choose the most appropriate answer from the options given below:
Consider a population of 10 million cells. Given the per-capita birth rate of 0.002 (per unit time) and the per-capita death rate of 0.002 (per unit time), the expected number of cells after 10 generations is:
Which of the following statements are correct? (a) Energy flow from producers to consumers is unidirectional (b) Energy pyramid can never be inverted (c) Transfer of energy follows the 1% law Choose the correct answer from the options given below:
Which of the following enzymes synthesizes precursor mRNA?
The regions with high level of species richness, high degree of endemism and a loss of 70% of the species and habitat are identified as:
In a chromosome, there is a specific DNA sequence, responsible for initiating replication. It is called as:
Given below are two statements:
Statement I: When many alleles of a single gene govern a character, it is called polygenic inheritance.
Statement II: In Polygenic inheritance, the effect of each allele is additive.
In the light of the above statements, choose the correct answer from the options given below.
Match List-I with List-II:
Which part of the ovule stores reserve food materials?
Which one of the following is not included under in-situ conservation?
Pollen grains remain preserved as fossils due to the presence of:
Given below are two statements regarding RNA polymerase in prokaryotes.
Statement I: In prokaryotes, RNA polymerase is capable of catalysing the process of elongation during transcription.
Statement II: RNA polymerase associate transiently with ‘Rho’ factor to initiate transcription.
In the light of the above statements, choose the correct answer from the options given below :
Given below are two statements:
Statement I: In eukaryotes there are three RNA polymerases in the nucleus in addition to the RNA polymerase found in the organelles.
Statement II: All the three RNA polymerases in eukaryotic nucleus have different roles.
Match List-I with List-II:
Given below are two statements:
Statement I: Failure of segregation of chromatids during cell cycle resulting in the gain or loss of whole set of chromosome in an organism is known as aneuploidy.
Statement II: Failure of cytokinesis after anaphase stage of cell division results in the gain or loss of a chromosome is called polyploidy.
In the light of the above statements, choose the correct answer from the options given below:
Given below are two statements:
Statement I: In the lac operon, the z gene codes for beta-galactosidase which is primarily responsible for the hydrolysis of lactose into galactose and glucose.
Statement II: In addition to lactose, glucose or galactose can also induce lac operon.
In the light of the above statements, choose the correct answer from the options given below:
The part marked as 'x' in the given figure is:
Consider the pyramid of energy of an ecosystem given below: If T₄ is equivalent to 1000 J, what is the value at T₁
Which one of the following is not a limitation of ecological pyramids?
When will the population density increase, under special conditions? When the number of :
When a tall pea plant with round seeds was selfed, it produced the progeny of : (a) Tall plants with round seeds and (b) Tall plants with wrinkled seeds. Identify the genotype of the parent plant.
Match List-I with List-II:
Match List-I with List-II:
Match List-I with List-II.
Match List-I with List-II relating to microbes and their products:
Aneuploidy is a chromosomal disorder where chromosome number is not the exact copy of its haploid set of chromosomes, due to:
A. Substitution
B. Addition
C. Deletion
D. Translocation
E. Inversion
The mother has A⁺ blood group the father has B⁺ and the child is A⁺. What can be the possibility of genotypes of all three, respectively?
What do 'a' and 'b' represent in the following population growth curve?