Tag: biology

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Questions Related to biology

Multiple choice biology inherited changes linkage and crossing over linkage and recombination genetics: inheritance

The primary biological importance of sex in organisms is that it

  1. Is essential for organismic reproduction

  2. Is essential for cellular reproduction

  3. Causes new mutations to occur in offspring

  4. Promotes genetic variability in offspring
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The primary biological advantage of sexual reproduction over asexual reproduction is the generation of genetic diversity through recombination and independent assortment, which aids in adaptation.

Multiple choice biology inherited changes linkage and crossing over linkage and recombination genetics: inheritance

P is the daughter of Q. R has only two children - P and S. T is the brother of U. S is married to V. R has only two daughters. X is the father of Q. T is married to P. W is married to X. R is the son of Y. Who among the following is the mother of Q?

  1. W

  2. Y

  3. R

  4. X
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

X is the father of Q. W is married to X. Therefore, W is the mother of Q.

Multiple choice biology inherited changes linkage and crossing over linkage and recombination genetics: inheritance

A DNA molecule measures 204 nm in length; 35% of the molecule has AT base pairs. Find out the number of H-bonds existing between the two strands of DNA.

  1. 1590

  2. 159

  3. 1410

  4. 141
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

DNA length 204 nm = 600 base pairs (0.34 nm/bp). 35% AT = 210 AT pairs (2 H-bonds each = 420). 65% GC = 390 GC pairs (3 H-bonds each = 1170). Total = 420 + 1170 = 1590.

Multiple choice biology inherited changes linkage and crossing over linkage and recombination genetics: inheritance

A human male is heterozygous for two autosomal genes A & B and homozygous dominant for 3rd autosomal gene C. The individual is having sry gene (S) on its Y-chromosome. What will be the probability of sperms to carry abcS condition? 

  1. $\frac{1}{4}$
  2. $\frac{1}{8}$
  3. $0$
  4. $\frac{1}{16}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The human male is heterozygous for A and B, and homozygous dominant for C, with genotype Aa Bb CC S (plus Y). To produce a sperm carrying the abcS condition, the sperm must receive recessive alleles a and b, but the individual is homozygous dominant for C (meaning only allele C is present, never c). Therefore, the probability of producing a sperm with the allele c is 0, making the overall probability 0.

Multiple choice biology inherited changes linkage and crossing over linkage and recombination genetics: inheritance

Assume that the occurrence of nitrogen bases in adjacent positions in a DNA strand is random. Identify the minimum number of nucleotides in a DNA strand where GAAT can occur once on the basis of probability

  1. 512

  2. 256

  3. 4096

  4. 1024
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The probability of a specific 4-nucleotide sequence occurring at any position is (1/4)^4 = 1/256. To expect this sequence to occur once, you need 256 positions. Thus, 256 nucleotides are required.