1. Early earth had no ozone layer, which means it was most likely extremely hot.
2. Young earth had no oxygen and life needs oxygen in order to survive.
3. There where so many natural disasters happening all the time, like volcanic eruptions and constant impact with meteorites and asteroids.
-Extra one (4. Earth originally had no ocean and water. Oceans eventually formed from the water vapor released from the volcanic eruptions, but before that there was nothing.)
Answer:
Option D.
Explanation:
The above answer given is incorrect. Nucleotides consist of a phosphate group attached to a pentose sugar, with 5 carbons, (deoxyribose sugar in the case of DNA) and the pentose sugar is also attached to a nitrogenous base. DNA is incorrect as nucleotides are the building block of DNA hence DNA is NOT a component of nucleotides.
The answer is B because:
Cell walls are made of cellulose and proteins (hence II).
Animal cells don't have cell walls (only cell membrane) but plant cells do so IV
They must be semipermeable since materials for example carbon dioxide and water for photosynthesis have to go into the cell <em>some</em> way.
Answer:
kidney
Explanation:
pancreas to regulate salt
Answer:
A. I, II, III, and V only
Explanation:
In genetics, an allele refers to the specific form of a gene, which encodes traits. These alleles are usually in pairs in a diploid organism i.e. an organism with two sets of chromosomes. According to Gregor Mendel,
- An allele can either be DOMINANT when the allele masks the phenotypic expression of its allelic pair while the allele that is masked is said to be RECESSIVE.
- Two alleles can also be CO-DOMINANT when the two alleles are neither dominant or recessive over one another but are simultaneously expressed in that particular gene.
- Alleles can also be INCOMPLETELY DOMINANT when one allele is not completely dominant over the other, hence, forms a third intermediate phenotype when in combination with the second allele i.e. in an heterozygous state.
Based on this, an allele can be dominant (I), recessive (II), codominant (III), and incompletely dominant (V).
