All Free Biology MCQs with Answers
Every Biology question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
19,844 questions · page 936 of 993
- A. Osteichthyes
- B. Cyclostomata
- C. Chondrichthyes
- D. None of these
Explanation: Cyclostomi, often referred to as Cyclostomata, is a group of vertebrates that comprises the living jawless fishes: the lampreys and…
Correct answer: Cyclostomata- A. Species, genus, family, order, class, phylum
- B. Order, family, class, phylum, kingdom
- C. Species, genus, family, class, order, phylum
- D. Species, genus, order, family, class, phylum
Explanation: The correct hierarchy of various taxa in biological classification is:Species, genus, family, order, class, phylumExplanation:1.
Correct answer: Species, genus, family, order, class, phylum- A. Nucleotide
- B. Nucleoside
- C. Nucleic Acid
- D. Polynucleotide
Explanation: Nucleosides are the structural subunit of nucleic acids such as DNA and RNA.
Correct answer: Nucleoside18704. Ester linkages occur in:
- A. Nucleic acids
- B. Nucleus
- C. Carbohydrates
- D. Proteins
Explanation: DNA and RNA are the chain of polynucleotides, that are joined by ester linkage known as 'phosphodiester bonds'.
Correct answer: Nucleic acids- A. Photolysis
- B. Condensation
- C. Deduction
- D. Convection
Explanation: Condensation is a chemical reaction where two molecules combine to form a larger molecule, typically accompanied by the release of water.
Correct answer: Condensation- A. Analogous.
- B. Homologous.
- C. Unilogous.
- D. Hypologous.
Explanation: Homologous organs are defined as the organs of different animals that are having a similar structure but differ in their functions.
Correct answer: Homologous.- A. DNA and proteins
- B. DNA and gene
- C. RNAs and proteins
- D. DNA and RNAs
Explanation: Explanation:Evolutionary relationships among species are reflected in their DNA and proteins - in their genes and gene products.
Correct answer: DNA and proteins18708. If all the members of a population are homozygous for the same allele, that allele is said to be:
- A. Random in population's pool
- B. Random in a species
- C. Fixed in population's pool
- D. Fixed in the gene pool
Explanation: Explanation:If all individuals in a population are homozygous for the same allele, then that allele is fixed in the population's gene…
Correct answer: Fixed in the gene pool- A. Haemoglobin
- B. Myoglobin
- C. Cytochrome c
- D. Pilin
Explanation: [A] Haemoglobin is not found in aerobic bacteria only in man[B] Myoglobin is found in man only[C] found in both man and aerobic bacteria s…
Correct answer: Cytochrome c- A. Embryology Record
- B. Molecular Record
- C. Biochemical Record
- D. Fossil Record
Explanation: Fossils are important evidence for evolution because they show that life on earth was once different from life found on earth today.
Correct answer: Fossil Record- A. Homologous
- B. Analogous
- C. Vestigial
- D. Fossilized
Explanation: Homologous organs can be defined as the organs of different animals that are similar in structure but perform different functions.
Correct answer: Homologous- A. Development of branchial arches invertebrate embryo.
- B. Distribution of species
- C. Comparison of genes and proteins in different species
- D. Study of vestigial organs
Explanation: To compare species to see how they have evolved differently, we look at their gene sequences or the amino acid sequence of essential…
Correct answer: Comparison of genes and proteins in different species- A. Hardy-Weinberg Theorem
- B. Mendel's law of independent assortment
- C. Mendel's law of segregation
- D. Theory presented by Schleiden and Schwann
Explanation: Hardy-Weinberg Theorem allows us to calculate the allele frequency in populations where the phenotype that we are examining is the same…
Correct answer: Hardy-Weinberg Theorem- A. Lipids.
- B. Caseins.
- C. Formaldehydes.
- D. Nucleoproteins.
Explanation: DNA is the genetic material, where a gene is a functional unit of DNA. Chromosomes are the carrier molecules for DNA that help in the…
Correct answer: Nucleoproteins.- A. Protein
- B. Lipid
- C. Glycoproteins
- D. Vitamins
Explanation: Glycoproteins are proteins that have carbohydrate chains (glycans) attached to them.
Correct answer: Glycoproteins- A. Cisternae
- B. Cytosol
- C. Endocytosis
- D. Both A and B
Explanation: The cytosol (the soluble portion of the cytoplasm outside the organelles) is mostly composed of water and many low molecular weight…
Correct answer: Cytosol- A. Smooth Endoplasmic Reticulum
- B. Ribosome
- C. Golgi Complex
- D. Rough Endoplasmic Reticulum
Explanation: Explanation:The phragmoplast is formed by vesicles that originally arise from the Golgi complex.
Correct answer: Golgi Complex- A. Tubulin
- B. Actin
- C. Myosin
- D. Troponin
Explanation: [A] The tubulin proteins α- and β polymerize into long chains or filaments that form microtubules.[B] Actin forms microfilaments in the…
Correct answer: Tubulin- A. Mitochondria
- B. Centrioles
- C. Ribosomes
- D. Lysosomes
Explanation: At the beginning of the nuclear division, two wheel-shaped protein structures called centrioles position themselves at opposite ends of…
Correct answer: Centrioles- A. 9
- B. 18
- C. 108
- D. 36
Explanation: Structure of a Centriole:Each centriole is composed of 9 microtubule triplets arranged in a cylindrical structure, forming the 9+0…
Correct answer: 36