Chromosomes are thread-like structures found within the nucleus of eukaryotic cells, first observed by Walther Fleming in 1882. They vary in number across species, with humans possessing 46 chromosomes organized into 23 pairs, each containing numerous genes essential for development and function. Chromosomes are primarily composed of DNA and protein, with DNA forming a long, double-stranded fiber that carries vast amounts of genetic information. The organization and behavior of chromosomes during cell division are crucial for heredity, as proposed by the chromosomal theory of inheritance, which asserts that genes are located on chromosomes and segregate during reproduction
What are chromosomes?
Chromosomes are thread-like structures located within the nucleus of eukaryotic cells, composed of DNA and proteins, and are essential for storing and organizing genetic information
What is the chromosomal theory of inheritance?
The chromosomal theory of inheritance posits that genes are located on chromosomes and segregate during reproduction, which was first formulated by Walter Sutton in 1902
What is the composition of chromosomes?
Chromosomes are primarily composed of about 40% DNA and 60% protein, with some RNA associated with them for synthesis purposes
What is a karyotype?
A karyotype is the particular array of chromosomes that an individual possesses, showing marked differences among species and sometimes among individuals of the same species
What are the two main types of chromatin found in chromosomes?
The two main types of chromatin are euchromatin, which is less condensed and active during gene expression, and heterochromatin, which is more condensed and often inactive
What are chromosomes primarily composed of?
a) RNA and lipids
b) DNA and proteins
c) Carbohydrates and proteins
d) DNA and carbohydrates
Answer: b) DNA and proteins
How many chromosomes do humans have?
a) 23
b) 46
c) 92
d) 44
Answer: b) 46
Who first observed chromosomes?
a) Gregor Mendel
b) Charles Darwin
c) Walther Fleming
d) James Watson
Answer: c) Walther Fleming
What is the term for the particular array of chromosomes in an individual?
a) Genome
b) Karyotype
c) Chromatid
d) Allele
Answer: b) Karyotype
What is the chromosomal theory of inheritance?
a) Genes are located on chromosomes and segregate during reproduction
b) Chromosomes are made of RNA
c) Chromosomes do not play a role in heredity
d) All chromosomes are identical
Answer: a) Genes are located on chromosomes and segregate during reproduction