Chapter 7: Cell Structure and Function

In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.

DNA

gene

Genetic diagrams show how characteristics are inherited. Alleles can be recessive, dominant or codominant genes. Pedigree analysis is used to show how genetic disorders are inherited. Biology (Single Science)

Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA). Passed from parents to offspring, DNA contains the specific instructions that make each type of living creature unique.

Chromosomes carry the basic genetic material DNA which is responsible to provide hereditary characteristics and genetic information to the various cells. The cellular functions are important for the growth and survival of living organisms.

Functions of Chromosomes The most important function of chromosomes is to carry the basic genetic material – DNA. DNA provides genetic information for various cellular functions. These functions are essential for growth, survival, and reproduction of the organisms. Histones and other proteins cover the Chromosomes.

Each chromosome is made up of two components (i) Deoxyribonucleic acid (DNA) (ii) Proteins (e.g.; his tones and acidic proteins) These consist of two (unreplicated) or four (duplicated) arms and a primary constriction or centromere which gives them a particular shape due to its position.

Humans have 48 chromosomes, 24 pairs, and that’s the end of that.

Sequencing all 24 human chromosomes uncovers rare disorders. Extending noninvasive prenatal screening to all 24 human chromosomes can detect genetic disorders that may explain miscarriage and abnormalities during pregnancy, according to a study by researchers at the National Institutes of Health and other institutions.

A large 275,000 (275 kb) bp region of human chromosome 22 encodes the genes APOL1, APOL2, APOL3, APOL4, and MYH9, and several coding genetic variations found in APOL1 are highly correlated with increased risk of kidney disease in subjects of African ancestry [9].

Humans normally have two copies of chromosome 22 in each cell. Chromosome 22 is the second smallest human chromosome, spanning about 49 million DNA base pairs and representing between 1.5 and 2% of the total DNA in cells….

Genetic testing is necessary to confirm a Jacobsen syndrome diagnosis. During genetic testing, magnified chromosomes are evaluated under a microscope. They’re stained to give them a “barcode” appearance. The broken chromosome and the genes that have been deleted will be visible.

Waardenburg syndrome is usually inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition.

Klinefelter syndrome affects males only; females cannot have it. Klinefelter syndrome results from a genetic abnormality in which males have an extra copy of the X chromosome. Instead of the usual XY chromosomes, males with Klinefelter syndrome have an XXY pattern.

Abstract. Langer-Giedion syndrome is a very uncommon autosomal dominant genetic disorder caused by the deletion of chromosomal material. It is characterized by multiple bony exostosis, short stature, mental retardation, and typical facial features.

In people with Nicolaides-Baraitser syndrome, a lack of subcutaneous fat in the hands makes the finger joints appear larger than normal. Over time, the fingertips become broad and oval shaped. Additionally, there is a wide gap between the first and second toes (known as a sandal gap ).

CHARGE syndrome is a disorder that affects many areas of the body. CHARGE is an abbreviation for several of the features common in the disorder: coloboma, heart defects, atresia choanae (also known as choanal atresia), growth retardation, genital abnormalities, and ear abnormalities.

The CHD7 gene encodes a member of the chromodomain helicase DNA-binding protein family that regulates the transcription of genes during embryonic development. Haploinsufficiency of CHD7 affects multiple organ systems, including the heart, the inner ear and the eye.