1. C) Both parents contributed a recessive allele
The offspring is homozygous for the recessive allele, which means it has two copies of it. Because each parent contributes one copy of the gene, this means that both parents contributed the recessive allele.
2. D) The offspring can be tall or short
The first cross between TT and tt will yield an F1 generation with the genotype Tt. When this generation is self-pollinated, the cross may result in the following genotypes:
TT, Tt, tt
Which means that the offspring can be tall or short.
...the DNA molecule that packaged into thread-like structures. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.
The Hertzsprung-Russell diagram is one of the most important tools in the study of stellar evolution. Developed independently in the early 1900's by Ejnar Hertzsprung and Henry Norris Russell, it plots the temperature of stars against their luminosity (the theoretical HR diagram), or the color of stars against their absolute magnitude
Depending on its initial mass, every star goes through specific evolutionary stages dictated by its internal structure and how it produces energy. Each of these stages corresponds to a change in the temperature and luminosity of the star, which can be seen to move to different regions on the HR diagram as it evolves. This reveals the true power of the HR diagram – astronomers can know a star’s internal structure and evolutionary stage simply by determining its position in the diagram.
The Hertzsprung-Russell diagram the various stages of stellar evolution. By far the most prominent feature is the main sequence (grey), which runs from the upper left (hot, luminous stars) to the bottom right (cool, faint stars) of the diagram. The giant branch and supergiant stars lie above the main sequence, and white dwarfs are found below it.
The answer is <span>Gap Junction
Gap junction is a small gap between the cells that used to transmit signall to the cells. This gap will allow the heart muscle to be activated in unison. Coordinated contractions are important for heart muscle because it creates the force that needed to pump the blood.</span>
<span>Depletion of the ozone layer. Choloroflourocarbon (CFCS) are dangerous because of their destructive reaction with Ozone particles, which provide the Earth with a protective layer or shield against UV radiation. Depletion of the ozone layer begins when when CFC gets into the stratosphere. Sunlight breaks up cfcs releasing Chlorine Atom. Chlorine atoms in turn react with Ozone, starting a chemical cycle that destroys the ozone layer in that area. Once the ozone layer is depleted, there's nothing holding back the harmful UVB wavelengths of ultraviolet light (UV light) from passing through the Earth's atmosphere causing havoc on plants and animals.</span>
