Answer:
16/64 = 1/4
Explanation:
This is a typical trihybrid cross involving three genes T, P and Y. A plant with genotype TTPpYy is crossed with a plant recessive for all traits (ttppyy).
According to Mendel's law of independent assortment, each allele for each gene will get sorted into the following 8 gametes with only 4 different: TPY, TPy, TpY, Tpy, TPY, TPy, TpY and Tpy.
The recessive parent, ttppyy will produce tpy, tpy, tpy, tpy, tpy, tpy, tpy and tpy.
Hence, using a punnet square, 64 offsprings will be produced with only 16 of them heterozygous dominant for the three traits with genotype (TtPpYy). Hence, proportion is 16/64 equivalent to 1/4.
Answer:
d. eon, era, period, epoch
Explanation:
The geological time scale has been made so that the scientists can have a practical system about the classification of geological time, thus everything that has happened throughout it. The geological time unites have been defined in accordance with important events that have happened, thus marking their end or beginning. These events can be mass extinctions, catastrophes, climate patterns, domination of certain species etc. The longest of these time units is the eon, lasting for more than half a billion years, and up to 2 billion years. The era comes as the second longest time unit, lasting for several hundred million years. The period lasts for several tens of million years, and the epoch is the smallest unit, lasting for few million years, or several hundred thousand years.
The correct answer is A.
Animal cells do not have a cell wall.
A cell wall is the rigid, outermost covering of plant cells and is made up of cellulose. It is absent in animal cells. The cell wall is visible under a light microscope.
Animal cells are instead covered by a cell membrane. It is made up of lipids, proteins, and small amounts carbohydrates. It is a thin and delicate structure that can only be seen using an electron microscope.
In an ecosystem, two factors are being classified which are the abiotic and the biotic factors. Both of these factors play an important role in order to balance the ecosystem and maintain the harmony of the living things therein. The environment includes the abiotic factors which are the sunlight, weather, water, air, and all other factors which are not living but contribute to the growth and development of the living ones. For example, plants cannot live without water, sunlight and carbon dioxide. The effects that humans have on the environment is both good and bad. Humans also play an important role in maintaining the environment, and they also have the capability to endanger it.
