MCQs in Biology... How to solve them

Slide 1 : Dr Subroto Biswas & Dr Aman Biswas Questions in Biology How to answer

For Online Biology Courses & Classroom Biology classes email Dr S Biswas / Dr Aman Biswas at bisbioin@gmail.com or call us at +91 09814016083 : For Online Biology Courses & Classroom Biology classes email Dr S Biswas / Dr Aman Biswas at bisbioin@gmail.com or call us at +91 09814016083

If you cross a pea plant that is homozygous dominant for tallness and one that is heterozygous, what will be the genotypes of the offspring that are tall ? ( if D and d represent the alleles for height in pea plants). : If you cross a pea plant that is homozygous dominant for tallness and one that is heterozygous, what will be the genotypes of the offspring that are tall ? ( if D and d represent the alleles for height in pea plants). A . All will DD B . Dd in most cases C. Dd only D . DD or Dd

If you have alternative versions of a gene that produce distinguishable phenotypic effects, then they are called………. : If you have alternative versions of a gene that produce distinguishable phenotypic effects, then they are called………. A . Genotypes B . Phenotypes C . Homozygous D . Alleles

In a plant where 2n= 24 what is the total number of chromatids present during prophase I of meiosis ? : In a plant where 2n= 24 what is the total number of chromatids present during prophase I of meiosis ? 6 12 24 48 96

A +G C + T : A +G C + T True for double stranded helical DNA False for double stranded helical DNA = 1 Chargaff's rules

Slide 7 : . A man with group B blood marries a woman with group A blood. Their child has group O blood. What are the genotypes and their frequencies you would expect in offspring ? A, B, or O AB only AB or O A, B, AB or O

“Lumpy jaw disease” of cattles is caused by : “Lumpy jaw disease” of cattles is caused by (a) Corybacterium bovis (b) Actinymyces bovis (c) Mycobacterium (d) Clostridium

Slide 9 : Lumpy jaw

4. GC rich DNA melts at a higher temperature than AT rich DNA : 4. GC rich DNA melts at a higher temperature than AT rich DNA True False

Slide 11 : GC base pair has three hydrogen bonds While AT has two. The third hydrogen bond helps understand why GC-rich DNA melts at higher temperatures compared to AT-rich DNA.

Slide 12 : . A black guinea pig crossed with an albino guinea pig produced 12 black offspring. When the albino was crossed with newly produced black offsspring ie second (F1) one, 7 blacks and 5 albinos were produced. What would be the genotypes for the parents, gametes, and offspring?

Slide 13 : There should be 50% black to 50% white offspring in this cross.

. “Crown galls” are caused by which of these organisms ? : . “Crown galls” are caused by which of these organisms ? (a) Mycobacterium (b) Erwinia (c) Agrobacterium (d) Clostridium

An Angiosperm leaf has 120 chromosomes its endosperm has : An Angiosperm leaf has 120 chromosomes its endosperm has 120 240 180 360

Which is the correct indication for Mendel’s Law of Segregation ? : Which is the correct indication for Mendel’s Law of Segregation ? A cross between parents pure for a certain trait will produce hybrids Chromosomes move apart during anaphase II of meiosis For genes that are not on the same chromosome, alleles assort independently of one another into gametes Alleles of a gene are sorted into separate sex cells and then recombine with another allele at fertilization

. Give the correct match for poultry disease causing organisms : . Give the correct match for poultry disease causing organisms A. Coryza 1. Histomonas (protozoan) B. Blackhead 2. H5 and H7 viruses C. New Castle 3. Paramyxovirus 1 D Avian influenza 4.Haemophilous bacterium A1 B2 C4 D3 A3 B2 C4 D1 A4 B1 C3 D2 A4 B1 C2 D3

New Castle disease : New Castle disease

Slide 19 : A man has six fingers on each hand and six toes on each foot. His wife and their daughter have the normal number of fingers. Considering extra digits to be a dominant trait what percentage of this couple's children would have extra digits ?

Slide 20 : The daughter is normal Man's genotype must be heterozygous Therefore, 50% of the offspring will be polydactylic

Where would you find Heterocysts which help in nitrogen fixation ? : Where would you find Heterocysts which help in nitrogen fixation ? red algae blue green algae (c) green algae (d) brown algae

Heterothallism in fungi was first discovered or described by : Heterothallism in fungi was first discovered or described by Robert Hooke Blakeslee (c) Warburg (d) Wallace

Slide 23 : What is Heterothallism? In some fungi there is no morphological sex differentiation, but they show physiological sex differences and said to be having +ve and -ve strains. Such fungi are called heterothallic. (heteros = dissimilar). In these fungi sexual reproduction can occur only between thalli having +ve and -ve strains

A rooster with gray feathers is mated with a hen of the same phenotype. Among their offspring, 15 chicks are gray, 6 are black, and 8 are white. What is the simplest explanation for the inheritance of these colors in chickens ? : A rooster with gray feathers is mated with a hen of the same phenotype. Among their offspring, 15 chicks are gray, 6 are black, and 8 are white. What is the simplest explanation for the inheritance of these colors in chickens ? A. Codominance B Incomplete dominance C. Blending theory D. Multiple alleles

A rooster with gray feathers is mated with a hen of the same phenotype. Among their offspring, 15 chicks are gray, 6 are black, and 8 are white.What offspring would you predict from the mating of a gray rooster and a black hen ? : A rooster with gray feathers is mated with a hen of the same phenotype. Among their offspring, 15 chicks are gray, 6 are black, and 8 are white.What offspring would you predict from the mating of a gray rooster and a black hen ? A. all black B. all gray C. Some black and some gray D. 3 black, 3 gray, 1 white

Slide 26 : A gray rooster (Bb ) mated to a black hen (BB ) can give…. 50% of the offspring gray (Bb ) and 50% black (BB )

In which of the following the compound, afflatoxin was first discovered ? : In which of the following the compound, afflatoxin was first discovered ? (a) Aspergillus flavus (b) Sclerospora graminicola (c) Puccinia graminis (d) Helminthosporium oryzae

Slide 28 : Afflatoxin

In a case of complete dominance, a cross between two parents who are pure for a certain trait will result in offspring that are : In a case of complete dominance, a cross between two parents who are pure for a certain trait will result in offspring that are A . heterozygous B . homozygous C . some homozygous some herterozygous D . incomplete dominance

What “turns off” the Lac Operon ? : What “turns off” the Lac Operon ? presence of lactose absence of lactose beta-galatosidase lacI A & D B & C

The genetic materials of an RNA virus, a DNA virus and a mammal were analysed (see below). Which of the following is a single stranded DNA virus ? : The genetic materials of an RNA virus, a DNA virus and a mammal were analysed (see below). Which of the following is a single stranded DNA virus ? Sample Adenine Cytosine Guanine Thymine Uracil 28.0 22.0 22.0 0.0 28.0 21.0 29.0 29.0 21.0 0.0 27.0 24.0 26.0 23.0 0.0

Slide 32 : Chargaff’s rule is followed by a mammalian double DNA …..sample B In DNA virus no uracil So C is the answer

The above refers to which of Mendel's Laws ? : The above refers to which of Mendel's Laws ? A . Law of Segregation B . Law of Dominance C . Law of Independent Assorment D . Law of recessiveness

The drug, Ergotine is derived from one of the following. Name it : The drug, Ergotine is derived from one of the following. Name it (a) Claviceps purpurea (b) Sclerospora graminicola (c) Cannabis saliva (d) Papaver somnifarum

Claviceps purpurea : Claviceps purpurea

Cycas revoluta is known as…...palm : Cycas revoluta is known as…...palm Sago Royal Sea Date

If Bhanu has 9 children, all girls and you find out that Bhanu is expecting another child, based on the possible sex chromosomes that can be contributed by the mother and father (Bhanu) what is the probability that the next child will be a boy ? : If Bhanu has 9 children, all girls and you find out that Bhanu is expecting another child, based on the possible sex chromosomes that can be contributed by the mother and father (Bhanu) what is the probability that the next child will be a boy ? A . 100% B . 25% C . 50% D . 75% E . 33%

Resin ducts found in conifers are : Resin ducts found in conifers are lysigenous schizegenous schizolysigenous laticiferous Schizogenous

8. In a wild …………type of strain of Drosophila the size of a gene from the start to stop codon is calculated to be 2000 nucleotide is pairs. However, the size of mRNA molecule transcribed from this gene is estimated at 1200 nucleotides. The most likely explanation for this discripancy in size would invoke the existence of : 8. In a wild …………type of strain of Drosophila the size of a gene from the start to stop codon is calculated to be 2000 nucleotide is pairs. However, the size of mRNA molecule transcribed from this gene is estimated at 1200 nucleotides. The most likely explanation for this discripancy in size would invoke the existence of A new stop codon introduced by mutation A frameshift mutation mRNA degradation DNA degradation The presence of one or more introns

An allele, dominant or recessive is dependent on…. : An allele, dominant or recessive is dependent on…. how common the allele is relative to other alleles whether it is inherited from the mother or the father whether it or another allele determines the phenotype when both are present whether or not it is linked to other genes

Avdesh was found to be heterozygous (Bb) for the bent little finger trait.  The alleles represented by the letters B and b are... : Avdesh was found to be heterozygous (Bb) for the bent little finger trait.  The alleles represented by the letters B and b are... on the X chromosome linked on homologous chromosomes both present in each of Avdesh’ sperm cells

Slide 42 : Base pairing in DNA is restricted to two base pairs represented as follows (lines between bases signify the number of hydrogen bonds) Which is the correct answer ? A=T and G C A T and G = C A G and T = C A= C and G T A T and G = C

A person is able to roll his/her tongue. It is a dominant phenotype. If we use T and t to represent the alleles associated with tongue rolling, what is the tongue-roller’s genotype? : A person is able to roll his/her tongue. It is a dominant phenotype. If we use T and t to represent the alleles associated with tongue rolling, what is the tongue-roller’s genotype? A . TT B . Tt C . tt D . B or C E . A or B

A process that occurs in meiosis but not mitosis is : A process that occurs in meiosis but not mitosis is pairing of Homologs Chromatid formation Cell division Separation of Homologus centromeres to opposite poles Chromosome condensation ( shortening)

Dimples on face are a dominant trait. A man and a woman is heterozygous for this trait. If they reproduce together, what is the probability that a child of theirs will possess dimples ? : Dimples on face are a dominant trait. A man and a woman is heterozygous for this trait. If they reproduce together, what is the probability that a child of theirs will possess dimples ? A . 25% B . 75% C . 50% D . 10% E . 100%

For Online Biology Courses &Classroom Biology classesemail Dr S Biswas / Dr Aman Biswasat bisbioin@gmail.comor call us at+91 098140 16083 : For Online Biology Courses &Classroom Biology classesemail Dr S Biswas / Dr Aman Biswasat bisbioin@gmail.comor call us at+91 098140 16083 The end