abida Archive

CHANGE IN CHROMOSOMAL STRUCTURE AND NUMB

Physical and chemical disturbance and errors occur during meiosis. They damage chromosome or alter their number in a cell. There can be folloyn chromosomal alterations: Point mutation The change of sequence of nucleotides is called point mutation. It is cau. by replacement, addition or

CHROMOSOMES AND GENE LINKAG

EUKARYOTIC CHROMOSOMES The chromosome is composed of DNA and histone protein. DNA is the genetic material. It exists with protein in the fix form. The chromosome shows following phases: Chromatin The highly dispersed state of chromosomes is called chromatin. The chromosome remains in chromatin

DEFINITIONS AND KEY POINTS OF INHERITENCE PATTERN

  TERMS ‘gut.          DEFINITIONS Mendel’s law of segregation The law of Mendel states that “the allele of gene present on   the     homologous chromosomes         segregates     during meiosis in such a way that each gamete get one allele not both”. Reciprocal crosses The cross with same

INHERITANCE PATTERN

MENDELIAN INHERITANCE PATTERN PRINCIPLE OF SEGREGATION The law of Mendel states that the allele of gene present on the homologous chromosomes segregates during meiosis in such a way that each gamete get one allele not both. The genes in each parent are incorporated into

OBJECTIVES OF CELL DIVISION

Mole Choice Questions MCQs Four options are given at the end of each statement. You should encircle one option from them. The centromere is a specific DNA sequence of about number of nucleotides. (a) 110                         (b) 230                         (c) 220                         (d) 330 DNA replicates during:

CONTROL OF CELL CYCLE

Different cells have different duration of cell cycle. Some cell actively divides like liver cells. But some cell never divides again like nerve cell. GI phase is a key period in the control of cell cycle and cell division. A crucial checkpoint occurs la

MITOSIS

The type of cell division in which number of chromosomes remains constant in the daughter generations is called mitosis. Mitosis is divided intc four phases: prophase, metaphase, anaphase, and telophase. However, thE process is continuous in a dividing cell.. Therefore, each phase smoothly enters