BIO II 1.4

homologous chromosomes

or ones that have the same genes even if they have different alleles.

meiosis

During gamete formation, cells undergo a process called

homologous recombination

meiosis involves the duplication of the genetic material prior to the actual division. However, the resulting daughter cells after meiotic division obtain one copy of each chromosome instead of two. Furthermore, it is during this division that ______ occurs.

autosomes

The 1st to 22nd pairs of chromosomes are called the

sex chromosomes

the 23rd pair of chromosome consists of the

sex-linked genes

Genes located on the sex chromosomes are called ______, so their phenotypic manifestation and inheritance patterns may vary between males and females.

X-linked trait

When a trait is controlled by a gene in the X chromosome, it is called an

Y-linked trait

If the trait is controlled by a gene in Y chromosome, it is called a

Color blindness

is the inability to distinguish certain colors.

monochromatism

some people with this condition can see objects only in shades of gray

dichromatism

some cannot distinguish one of the primary colors of light: red, blue, green

anomalous trichromatism

while others still see colors but find it difficult to distinguish shades of a certain color

Ishihara chart

is used as a test for color blindness. It is named after its inventor, a Japanese ophthalmologist named Shinobu Ishihara.

Hemophilia

is a rare inherited bleeding disorder. People with this condition bleed longer after an injury compared with a normal person.

hypertrichosis pinnae auris

This trait is characterized by having hairy ears.

Special lenses

are developed to help color-blind people distinguish the colors of the white light spectrum.

Recombination is a mechanism where the homologous pairs of chromosomes exchange genes.

Sex-influenced traits

can be found in both sexes but expressed more in one sex than in the other.

Sex-limited traits

have genes that can be found in both sexes but only one sex expresses it on their phenotype.

Sex linkage

is termed as such because their phenotypic manifestation and inheritance patterns vary between males and females.