Name the following
a. The substance found in chromatin material other than
DNA.
b. The mitotic phase before cytokinesis.
c. The nitrogenous base which pairs with cytosine in DNA.
d. The part of plant where meiosis results in the formation of
male gametes.
e. The phase in which no change occurs in DNA
Answers
Answer:
1. Chromatin is a substance within a chromosome consisting of DNA and protein. The DNA carries the cell's genetic instructions. The major proteins in chromatin are histones, which help package the DNA in a compact form that fits in the cell nucleus.
2. These phases occur in strict sequential order, and cytokinesis - the process of dividing the cell contents to make two new cells - starts in anaphase or telophase. Stages of mitosis: prophase, metaphase, anaphase, telophase. Cytokinesis typically overlaps with anaphase and/or telophase
3. Guanine (G) is paired with cytosine (C) via three hydrogen bonds, in red. Adenine (A) is paired with uracil (U) via two hydrogen bonds, in red. Purine nucleobases are fused-ring molecules.
4. The organism's diploid germ-line stem cells undergo meiosis to create haploid gametes (the spermatozoa for males and ova for females), which fertilize to form the zygote
5. The S Phase of Interphase
The S phase only begins when the cell has passed the G 1 { G }_{ 1 } G1 checkpoint and has grown enough to contain double the DNA. S phase is halted by a protein called p16 until this happens.