Answer:
Day time period have we as humans been here: 26 seconds
Explanation:
4,500,000,000 years = 1 day
1,400,000 years = X
X = 0.0003111
1 day = 86,400 seconds
0.0003111 = X
X = 26 seconds
In term of the Earth in 24-hour clock, <em>Homo sapiens</em> appeared on our planet only in the last 26 seconds, it means that in geologic time, humans have existed for only a brief time period and thereby it is a relatively new species.
Answer:(B) decrease protein production
Explanation: nitrogen gas in the atmosphere is the source of nitrogen which is useful to plants.
In the nitrogen cycle, nitrogen gas is converted to it's compounds and then back to it's gas form.
The nitrogenous cycle involves fixation, mineralization, nitrification and denitrification .
In the first three states, nitrogen undergoes changes into a state where it can be absorbed by plants.
In denitrification,nitrates (useful form of nitrogen) are converted into gaseous nitrogen.organisms involved in this process are called denitrifying bacteria eg Pseudomonads sp.
Nitrogen is an important element.
It is useful for the production of protein, DNA, RNA and chlorophyll.
When it is deficient in the soil,it affects the synthesis of proteins and yellowing of leaves due to decrease in chlorophyll
Answer:
The fork is drawn to emphasize its similarity to the bacterial replication fork depicted in Figure. Although both forks use the same basic components, the mammalian fork differs in at least two important respects.
First, it uses two different DNA polymerases on the lagging strand.
Second, the mammalian DNA primase is a subunit of one of the lagging-strand DNA polymerases, DNA polymerase α, while that of bacteria is associated with a DNA helicase in the primosome. The polymerase α (with its associated primase) begins chains with RNA, extends them with DNA, and then hands the chains over to the second polymerase (δ), which elongates them. It is not known why eucaryotic DNA replication requires two different polymerases on the lagging strand. The major mammalian DNA helicase seems to be based on a ring formed from six different Mcm proteins; this ring may move along the leading strand, rather than along the lagging-strand template shown here.
Reference: Molecular Biology of the Cell. 4th edition. Alberts B, Johnson A, Lewis J, et al. New York: Garland Science; 2002.
Answer:
Which of the following statements about the cytoskeleton is false?
The cytoskeleton helps organize the cell’s structure and activities
Explanation:
Don’t copy in exam or u will suffer later
