NCTB Class 8 science Chapter 2“Growth and Heredity of Living Organism” Solution

Bangladesh Board Class 8 science Solution Chapter 2“Growth and Heredity of Living Organism” Exercises Question and Answer by Experienced Teacher.

NCTB Solution Class 8 Chapter 2 “Growth and Heredity of Living Organism”

Board	NCTB Bangladesh Board
Class	8
Subject	science
Chapter	Two
Chapter Name	“Growth and Heredity of Living Organism”

Fill in the blanks:

(1) In —- stage the chromosomes with their chromatid take position at the equatorial region.

Answer:-

(2) Reduction of chromosome occurs in —- division.

Answer:- Telophase.

(3) In Amoeba — is found.

Answer:-  Amitosis.

(4) The nature of chromosome in somatic cells is ——.

Answer:- Mitosis.

(5) The division of nucleus is called ——–.

Answer:- Cary kinesis.

Multiple choice questions:

(1) (a) In which stage of mitosis chromosomes becomes shorter and thicker?

Answer:- Metaphase.

(2) Which of the following controls eye colour?

Answer:- RNA.

(3) Which stage of cell division Safwan observed?

Answer:- Metaphase.

(4) In the next phase of Safwan’s observation-

Answer:- (ii) & (iii).

Creative questions:

(1) (a) Which type of cell division produces germ cells?

Answer:- Meiosis cell division produces germ cell.

(1) (b) What do you mean by amitosis? Explain.

Answer:- Amitosis is a cell division which occurs in Bactria, yeast, fungi and in amoeba.

(1) (c) Describe with diagram the stage of cell division that Mr. Farabi describes.

Answer:- In anaphase stage of mitosis cell division, the centromere of the chromosome divides into two independent daughter chromosome in nucleus. The number of chromosomes remain unchanged in the daughter cells.

(1) (d) Explain the role of thread like structure that Mr. Farabi describes.

Answer:- The role of thread like structure that Mr. Farabi describes are, it acts carrier and transmit gene from one generation to next generation, thus maintains the continuity of hereditary traits. It carries gene directly from parent to offspring during cell division.

(2) (a) How many chromosomes are there in a human somatic cells?

 Answer:-There are 46 chromosomes in human somatic cells.

(2) (b) What do you mean by gene?

 Answer:- Gene is the carrier of heredity and chromosome transmits them from generation to generation.

(2) (c) Explain cell division P?

Answer:- In the cell division P, the nucleus is divided twice and chromosomes divided once. As a result of P cell division the number of chromosomes of the daughter cells becomes half of the number of chromosomes of mother reproductive cells.

(2) (d) In case of higher animals compare the call divisions P and Q

Answer:- In case of higher animals.