psychologicalblogspot

Q. 1 Multiple-Choice Questions  1. Griffith worked on ............. a. Bacteriophage  b. Drosophila   c. Frog eggs  d. Streptococci ANS: d. Streptococci Frederick Griffith was a British bacteriologist who worked on the bacteria Streptococcus pneumoniae, which causes pneumonia. In his famous experiment, he discovered the phenomenon of bacterial transformation, where genetic material could be transferred from one strain of bacteria to another. 2. The molecular knives of DNA are …………..  a. Ligases  b. Polymerases   c. Endonucleases  d. Transcriptase ANS:  c. Endonucleases Endonucleases are enzymes that cleave the phosphodiester bonds within a DNA molecule. They are often referred to as molecular knives because they can cut DNA at specific locations, allowing researchers to manipulate DNA sequences. 3. Translation occurs in the ...............  a. Nucleus  b. Cytoplasm  c. Nucleolus  d. Lysosomes ANS: b. Cytoplasm Tr...

The Discovery of DNA: In 1869, Friedrich Miescher isolated a unique chemical substance from white blood cells called nuclein. Nuclein was found to have high phosphorus content and showed acidic properties, leading to its name nucleic acid. By the early 1900s, it was discovered that nuclein was a mixture of proteins and nucleic acids. There are two types of nucleic acids: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). The development of the double-helix model helped further the understanding of DNA and its role in genetics. The Genetic Material is DNA: By the early 1900s, geneticists knew that genes controlled the inheritance of traits and were located on chromosomes composed mainly of DNA and proteins. Initially, geneticists thought that proteins were the genetic material that caused variations observed within species. It was thought that DNA was a small and simple molecule that varied little among species. However, over time, it was shown that DNA molecules are large and vary...

Q. 1 Multiple choice questions. 1. The number of nuclei present in a zygote is …… a. two b.one c. four d.eight ANS:  b. one  A zygote is formed when a sperm cell fertilizes an egg cell, resulting in the fusion of their nuclei. Therefore, a zygote has only one nucleus. 2. Which of these is the male reproductive organ in human? a. sperm b. seminal fluid c. testes d. ovary ANS: c. testes Th e testes are the male reproductive organs in humans. They produce sperm and the male hormone testosterone. 3. Attachment of embryo to the wall of the uterus is known as…….. a. fertilization b. gestation c. cleavage d. implantation ANS: d. implantation  Implantation is the process by which the fertilized egg attaches itself to the wall of the uterus and begins to develop into an embryo. 4. Rupturing of follicles and discharge of ova is known as .............. a. capacitation b. gestation c. ovulation d. copulation ANS; c. ovulation Ovulation is the process in which the follicles in the ov...