Cell, the smallest unit that can exist independently
Answer:
The correct answer is C) It catalyzes the lengthening of telomeres, compensating for the shortening that could occur during replication without telomerase activity.
Explanation:
While replicating, the ends of the chromosomes always lose a part of the ends, therefore, the telomerase catalyzes this growing process, somehow compensating the information that will be lost.
Answer:
C) binding to mRNAs and degrading them or blocking their translation
Explanation:
<u>miRNAs:</u>
miRNAs is the abbreviation of MicroRNAs. These are the small noncoding RNAs of ∼22 nucleotides which can not code for peptides. miRNAs are responsible for gene expression regulation at the level of post transcription. They can do so by forming complementary base pairing with target mRNA and inhibiting their translation.
They silenced mRNA by the following processes:
(1) Cleavage of the mRNA strand into pieces,
(2) stopping mRNA from translation into proteins by ribosomes.
(3) Shortening of mRNA poly(A) tail and destabilizing it.
PP- purple homozygote
pp- white homozygote
Pp- purple hetrozygote
If these flowers cross, we obtain heterozygote offsprings with a genotype: Pp (100% of them will be like this)
Now, if those offsprings cross with each other: Pp x Pp
results:
1/4 would be purple homozygote -> PP
1/4 would be white -> pp
2/4 would be purple heterozygotes -> Pp
Genotipic ratio: 3:1 (3 are purple; 1 is white)