The 'Avery, MacLeod, and McCarty' experiment in 1944 provided strong evidence that: MCQ with Answer and Explanation

The 'Avery, MacLeod, and McCarty' experiment in 1944 provided strong evidence that:
A. RNA is the genetic material in some viruses
B. Lipids are the genetic material
C. Proteins are the genetic material
D. DNA is the genetic material
Answer: Option D
Solution (By JKExamLibrary)
In 1944, Oswald Avery, Colin MacLeod, and Maclyn McCarty conducted a landmark experiment building on Griffith's transformation experiment. They purified various macromolecules (DNA, RNA, proteins, lipids) from the virulent S strain of Streptococcus pneumoniae and tested which one could transform the non-virulent R strain into the virulent form. They found that only DNA could cause transformation, and this activity was destroyed by DNase but not by RNase or proteases. This provided the first strong, direct evidence that DNA, not protein, is the genetic material.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Biology Questions

Question #1
Consider statements about human immunity: 1. Innate immunity is present from birth. 2. Vaccination provides artificial active immunity. 3. Antibodies are produced by T-lymphocytes. Which are correct?
A. 1 and 2 only
B. 2 and 3 only
C. 1 and 3 only
D. 1, 2 and 3

Correct Answer: Option A


Explanation:
Innate immunity is the non-specific defense mechanism present by birth, including physical barriers and phagocytes. Vaccination introduces antigens to stimulate the body's own antibody production, conferring artificial active immunity. Antibodies (immunoglobulins) are produced and secreted by B-lymphocytes (plasma cells), not T-lymphocytes, which are involved in cell-mediated immunity. Thus, statements 1 and 2 are correct.

This question belongs to: Science Biology
Question #2
The forelimbs of humans, whales, and bats exhibit similarity in basic structure due to common ancestry. This is an example of:
A. Homologous organs
B. Analogous organs
C. Vestigial organs
D. Adaptive radiation

Correct Answer: Option A


Explanation:
Homologous organs share a common ancestral origin and structural plan but may have different functions (e.g., human arm, whale flipper, bat wing). This indicates divergent evolution. Analogous organs have different origins but similar functions (e.g., wings of birds and insects) due to convergent evolution. Vestigial organs are reduced and non-functional, like the human appendix.

This question belongs to: Science Biology
Question #3
The structure in the female reproductive system where the fetus develops is the:
A. Uterus
B. Fallopian tube
C. Vagina
D. Ovary

Correct Answer: Option A


Explanation:
The uterus is a hollow, muscular organ where the fertilized egg implants into the endometrium and develops into an embryo and fetus. The ovaries produce eggs and hormones, the fallopian tubes are the fertilization site, and the vagina is the birth canal and copulatory organ.

This question belongs to: Science Biology