What is a palindromic sequence of DNA?
What Is a DNA Palindrome? A palindromic sequence of nucleotides (which are labeled A, T, C, or G) occurs when complementary strands of DNA read the same in both directions, either from the 5-prime end or the 3-prime end.
Is the Y chromosome a mutation?
A mutation in SOX3 created the gene SRY on the Y chromosome. Researchers found that monotremes are the most ancient mammals that have the SRY gene, whereas all earlier ancestors do not. These data allowed researchers to estimate when the mutation that created SRY occurred.
What does the Y chromosome indicate?
The Y chromosome contains a “male-determining gene,” the SRY gene, that causes testes to form in the embryo and results in development of external and internal male genitalia. If there is a mutation in the SRY gene, the embryo will develop female genitalia despite having XY chromosomes.
What does palindromic mean in biology?
Palindrome: In genetics, a DNA or RNA sequence that reads the same in both directions. The sites of many restriction enzymes that cut (restrict) DNA are palindromes.
Is the Y chromosome a defect?
However, Y chromosomes have a fundamental flaw. Unlike all other chromosomes, which we have two copies of in each of our cells, Y chromosomes are only ever present as a single copy, passed from fathers to their sons.
How is the Y chromosome formed?
The X and Y chromosomes are thought to have evolved from a pair of identical chromosomes, termed autosomes, when an ancestral animal developed an allelic variation, a so-called “sex locus” – simply possessing this allele caused the organism to be male.
Can humans have 2 Y chromosomes?
XYY syndrome is a rare chromosomal disorder that affects males. It is caused by the presence of an extra Y chromosome. Males normally have one X and one Y chromosome. However, individuals with this syndrome have one X and two Y chromosomes.
What type of chromosome is Y chromosome?
two sex chromosomes
The Y chromosome is one of two sex chromosomes (allosomes) in therian mammals, including humans, and many other animals. The other is the X chromosome….Y chromosome.
| Human Y chromosome | |
|---|---|
| Type | Allosome |
| Centromere position | Acrocentric (10.4 Mbp) |
| Complete gene lists | |
| CCDS | Gene list |
Why is the Y chromosome passed from father to son?
The Y chromosome is a puny bit of DNA that has only a few genes. And the genes it does have mostly deal with being male. So the only traits that are passed from father to son through the Y are those that turn an embryo into a male and those that make a man fertile once he reaches puberty.
What are Y chromosome palindromes?
Y chromosome palindromes and gene conversion The presence of large and near-identical inverted repeat sequences (called palindromes) is a common feature of the constitutively haploid sex chromosomes of different species. Despite the fact palindromes originated in a non-recombining context, they have evolved a strong recombinational activity in …
What is a palindromic sequence in DNA?
Certain DNA sequences have a twofold inverted symmetry and are called self-complementary or palindromic sequences. Palindromic sequences are the usual recognition sites for restriction enzymes and frequently occur as essential elements in regulatory regions.
What is the role of palindromes in protein function?
Palindromes also appear to be found frequently in the peptide sequences that make up proteins, but their role in protein function is not clearly known.
How do palindromes occur in single stranded molecules?
See Fig. 243 .In a single-stranded molecule, COMPLEMENTARY BASE PAIRING can occur when the chain is folded back (See also HAIRPIN ). Palindromes occur in, for example, many operator sequences (see OPERON MODEL ), transcription terminator sequences (see TRANSCRIPTION ).and most recognition sites for RESTRICTION ENZYMES.