Populational change is Darwin’s hypothesis that evolution occurs by changes in the proportions (frequencies) of different variant kinds of individuals within a population.

TLS Online TPP Program

#Id: 3701

#Unit 2. Cellular Organization

In any particular cell, most genes are expressed at a low level

Only a small number of genes, whose products are specialized for the cell type, are highly expressed.

mRNAs expressed at low levels overlap extensively when different cell types are compared.

The abundantly expressed mRNAs are usually specific for the cell type.

TLS Online TPP Program

#Id: 3702

#Unit 2. Cellular Organization

The proportion of DNA containing protein-coding genes being expressed in a specific cell at a specific time can be determined by the amount of the DNA that can hybridize with the mRNAs isolated from that cell called as RoT analysis

TLS Online TPP Program

#Id: 3703

#Unit 2. Cellular Organization

Highly repetitive DNA (or satellite DNA) has a very short repeating sequence and no coding function.

Satellite DNA is often the major constituent of centromeric heterochromatin

TLS Online TPP Program

#Id: 3704

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 3705

#Unit 2. Cellular Organization

Many genes are arranged along the chromosomes in groups of related genes. These groups are called gene clusters. Examples of gene clusters are the globin gene family.

TLS Online TPP Program

#Id: 3706

#Unit 2. Cellular Organization

When a genome contains a cluster of genes with related sequences, mispairing between nonallelic loci can cause unequal crossing over. This produces a deletion in one recombinant chromosome and a corresponding duplication in the other.