BIO 235 Exam 1 With 100% Correct
Answers 2025/2026
While undergoing mitosis, the ____ is the central regio on DNA that connects sister
chromatids - Correct Answer-Centromere
Homologous chromosome pairs...? - Correct Answer-have a chromosome from mother
and father, synapse during prophase of meiosis 1, same genes but different alleles, pair
of sister chromatids during prophase meiosis 1
What stage of the cell cycle does DNA replication occur in preparation for division? -
Correct Answer-S phase
What is one defining difference between DNA of G2 and G1 phases of the cell cycle? -
Correct Answer-G2 nucleus has 2 copies of each chromosome
How many centromeres exist in the G1 phase of a diploid organism with 24
chromosomes? - Correct Answer-24
A mammal's gametes contain 24 chromosomes (1n=24) how many chromosomes
would we expect to find in its adult (somatic) cells? - Correct Answer-48
Meiosis 2 results in a reduction, or halving of the number of chromosomes in each
daughter cell. - Correct Answer-False
List 2 of the mechanisms discussed in class by which meiosis produces genetic
variation - Correct Answer-1.random orientation/distribution of homologous
chromosomes in anaphase 1
2. crossing over
What is a bivalent? - Correct Answer-a pair of homologous chromosomes which consist
of sister chromatids
How many chromatids are in 4 bivalents? - Correct Answer-16
In meiosis, ___ separate during meiosis 1, and ___ separate during meiosis 2 - Correct
Answer-homologous pairs, sister chromatids
When an allele masks another allele in a heterozygote, preventing expression of the
masked allele, this allele can be described as? - Correct Answer-dominant
In plants, meiosis results in an entire haploid _____ generation from the diploid _____
generation - Correct Answer-gametophyte, sporophyte
