Question

think about it - as geneticists in the early 1900s applied mendel’s laws, they wondered where ____ might be ________. - they expected genes to be carried on ________________________, but which structures? - what cellular processes could account for ____________ and __________________, as mendel had described? chromosome number - ___________—those ____________ and protein inside the cell nucleus—are the ____________________. - the ___ are located in _________________ on ___________. diploid cells - a _________ in an adult fruit fly has ______________________. - __ of the chromosomes ___________________________, and _ come from its ________________. - these two sets of chromosomes are _____________, meaning that each of the four ___________ from the __ parent has a _____________ chromosome from the ________________. - a cell that contains ________ of __________ chromosomes is ___, meaning “______.” - the _______________ of chromosomes is sometimes ___________ by the ___ . - for the fruit fly, the _____ number is _, which can be written as __ = . - dipoid cells have ___ the number of __________ in a __ or __ cell. haploid cells - some cells contain only a ________ of chromosomes, and therefore a ________ ____________. - such cells are _______, meaning “______.” - the _____ of ____________________ organisms are _______.

Explanation:

These fill-in-the-blank questions cover foundational genetics concepts about chromosome theory, ploidy, and Mendelian inheritance, based on early 20th-century genetic research and basic cell genetics.

Answer:

THINK ABOUT IT

• As geneticists in the early 1900s applied Mendel's laws, they wondered where genes might be located in the cell.
• They expected genes to be carried on cellular structures, but which structures?
• What cellular processes could account for segregation and independent assortment, as Mendel had described?

Chromosome Number

• Chromosomes—those DNA and protein inside the cell nucleus—are the carriers of genes.
• The genes are located in specific positions (loci) on chromosomes.

Diploid Cells

• A somatic cell in an adult fruit fly has 8 chromosomes.
• One set of the chromosomes comes from its female parent, and one set come from its male parent.
• These two sets of chromosomes are homologous, meaning that each of the four chromosomes from the female parent has a corresponding chromosome from the male parent.
• A cell that contains two sets of homologous chromosomes is diploid, meaning "two sets."
• The chromosome number of chromosomes is sometimes represented by the symbol \(2n\).
• For the fruit fly, the diploid number is \(8\), which can be written as \(2n = 8\).
• Diploid cells have twice the number of chromosomes in a sperm or egg cell.

Haploid Cells

• Some cells contain only a single set of chromosomes, and therefore a single set of genes.
• Such cells are haploid, meaning "single set."
• The gametes of sexually reproducing organisms are haploid.