FBISE Class 9th (SSC-l)
Explore subjects and practice MCQs
3
Chapters
1,610
Total MCQs
FBISE Class 9th (SSC-l)
Answer: Meiosis II resembles mitosis because sister chromatids separate without any further reduction in chromosome number.
Answer: In anaphase II, the centromere divides and sister chromatids separate and move to opposite poles.
Answer: Interkinesis is a brief stage between meiosis I and meiosis II during which no DNA replication occurs.
Answer: Meiosis I reduces the chromosome number from diploid (2n) to haploid (n).
Answer: During diplotene, the homologous chromosomes begin to separate and the chiasmata (sites of crossing over) become visible.
Answer: Gametes are haploid, so they receive half the chromosome number, i.e., n = 4.
Answer: Homologous pairs align randomly on the equator during metaphase I, allowing maternal and paternal chromosomes to assort independently.
Answer: Crossing over and independent assortment during meiosis generate genetically different gametes, increasing variation.
Answer: Prophase I is divided into five substages: leptotene, zygotene, pachytene, diplotene and diakinesis.
990
Answer: In leptotene, the first substage, chromosomes condense and appear as thin threads.
Answer: Diploid cells contain two sets of chromosomes, represented as 2n.
Answer: Haploid cells contain one set of chromosomes, represented as n.
Answer: Somatic cells contain two sets of chromosomes and are diploid (2n).
994
Answer: Gametes contain one set of chromosomes and are haploid (n).
Answer: In zygotene, homologous chromosomes start to pair up, beginning synapsis.
Answer: Human somatic cells contain 46 chromosomes (23 pairs), i.e., 2n = 46.
Answer: Human gametes contain 23 chromosomes, i.e., n = 23.
Answer: Homologous chromosomes carry genes controlling the same traits, although the alleles may differ.
Answer: Gametes are haploid, so they contain half of the diploid number, i.e., 15 chromosomes.
Answer: In diakinesis the chromosomes become maximally condensed and the chiasmata move toward the ends of the chromosome arms, a process called terminalization.