Answer:
Huntington disease is a dominant autosomic disease so it presents either in heterozygosity (Aa) or in homofzigosity (AA)
observing the pedigree, the two parents have the Aa genotype so by making the punnet's square we have as possible genotypes: AA, Aa, Aa, aa. So the chance to get the disease is 25%
Answer:
Vestigial organs are a type of homologous organs.
Explanation:
Vestigial organs are rudimentary in present organisms. Vestigial organs such as wisdom teeth,nictating membrane of eyes,body hairs,which were functional organs in ancestors. Though they are present in an organism in reduced form but are functionless.
Examples of vestigial organs:
1. Human tail or appendix,
2. Pelvic bone of a snake
3. Wings of flightless birds
4.Male breast tissues and nipples
The raw materials of photosynthesis are, sunlight, water and C02.
Answer:
It seems possible that the origin of life on the Earth's surface could have been first prevented by an enormous flux of impacting comets and asteroids, then a much less intense rain of comets may have deposited the very materials that allowed life to form some 3.5 - 3.8 billion years ago.
Explanation:
