A lesion that interrupts one optic nerve causes blindness in that eye.

TLS Online TPP Program

#Id: 3694

#Unit 2. Cellular Organization

Genes are not uniformly distributed in the genome.

Regions longer than 500 kb where there are no ORFs called as deserts

The most gene-rich chromosomes have 10% of their sequences as deserts. So overall, 20% of the human genome consists of deserts that have no protein coding genes.

TLS Online TPP Program

#Id: 3695

#Unit 2. Cellular Organization

The Y chromosome has 60 genes that are expressed specifically in the testis.

TLS Online TPP Program

#Id: 3696

#Unit 2. Cellular Organization

Not all genes are essential. In yeast and flies, deletions of 50% of the genes have detectable effects

TLS Online TPP Program

#Id: 3697

#Unit 2. Cellular Organization

Most known genetic defects in human genes are due to point mutations. The majority directly affect the protein sequence

TLS Online TPP Program

#Id: 3698

#Unit 2. Cellular Organization

Deletion appears to have no effect when genes are present in multiple copies called as gene redundancy

TLS Online TPP Program

#Id: 3699

#Unit 2. Cellular Organization

Genetic redundancy means that two or more genes are performing the same function and that inactivation of one of these genes has little or no effect on the biological phenotype

Redundancy seems to be widespread in genomes of higher organisms