Biology - Study Mode

[#301] In man there are how many pairs of homologous chromosomes?
Correct Answer

(B) 23

Explanation

Solution: In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46.

[#302] It is composed of two polynucleotide chains which are coiled around each other in the form of a double helix.
Correct Answer

(A) DNA

Explanation

Solution: DNA) is a molecule composed of two polynucleotide chains that coil around each other to form a double helix carrying genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses. DNA and ribonucleic acid (RNA) are nucleic acids.

[#303] How many chromosomes are in a human gamete?
Correct Answer

(A) 23

Explanation

Solution: In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46.

[#304] What is the unit of heredity?
Correct Answer

(C) Gene

Explanation

Solution: A gene is the basic physical and functional unit of heredity. Genes are made up of DNA.

[#305] Who discovered genetic material?
Correct Answer

(C) Friedrich Griffith

Explanation

Solution: In the 1920s, Frederick Griffith made an important discovery. He was studying two different strains of a bacterium, called R (rough) strain and S (smooth) strain.