Answer: The correct answer is-
A. organs, but no true body cavity.
Based on the presence of body cavity ( also called coelom), multicellular animals can be classified as acoelomates ( no true body cavity), coelomates ( having true body cavity), pseudocoelomates ( false body cavity).
Roundworms are pseudocoelomic. This means that organs are present but the body cavity is not lined by mesodermal epithelium.
Body cavity is present between the external wall of body and the intestine and it baths the different body organs.
Thus, option A) is the right answer.
Answer:
Option A
Explanation:
All bilateral organisms have coelomates (cavity). However a Pseudocoelomate organism have a false cavity. By false cavity, we mean that there is a body cavity which is filled with fluid and all internal organs bathe in it including alimentary canal system , reproductive system etc. Unlike a coelom, Pseudocoelomate organism do not have body cavity completely lined with mesodermal cells.
hence, option A is correct
Chase and Hershey conducted experiments in 1952, using bacteriophages that revealed DNA, not protein, was the genetic material.
The experiments that revealed protein was not the genetic material were conducted by Martha Chase and Alfred Hershey in 1952. They were studying a bacteriophage, a virus that infects bacteria, which has two main structures: a protein coat known as the capsid, and a nucleic acid core that contains either DNA or RNA.
Hershey and Chase used radioactive markers to label the protein coat and DNA of the bacteriophage, respectively. Through their experiments, Hershey and Chase discovered that only the DNA entered the host bacteria upon bacteriophage infection, suggesting that DNA, not protein, is the genetic material. Their work was instrumental in establishing DNA as the molecule responsible for heredity.
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Answer: A.Caffeine
Explanation:
Caffeine works by blocking adenosine, a neurotransmitter that promotes sleep. This makes us feel more awake and alert. It's the most commonly used psychoactive substance and is found in many everyday items like coffee and medicines.
The actual mechanism of A) Caffeine is to block chemicals that inhibit or slow nerve activity in the brain. Caffeine functions as an adenosine antagonist, meaning it inhibits the adenosine receptors. Adenosine is a neurotransmitter that promotes sleep, so caffeine's effect reduces sleepiness and enhances alertness.
This mechanism allows caffeine to indirectly increase adrenergic activity (energy release), promoting a more energetic state. While caffeine is often associated with increased alertness and arousal, it's important to remember that it's acting primarily by blocking the inhibiting effect of certain chemicals on the brain nerve activity.
It's noteworthy that caffeine, as the world's most widely consumed psychoactive drug, is unregulated, found in everyday items like beverages and medicines, and generally not harmful in moderation.
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We are given with 2 genes homozygous tall plants (TT) with homozygous short plants (tt). The ensuing offspring are tall, which implies the dominant attribute is tallness. this can be true since the chance of various height like all are short or some are tall and short could also be doable. answer is a
allele for tall plant height was dominant
Explanation:
Gregor Johann Mendel, called the "father of recent biology," was born in European country in 1822. His experiments showed that the inheritance of bound traits in pea plants follows explicit patterns, later turning into the inspiration of recent biology and resulting in the study of heredity.
Explanation:
Before leaving the nucleus, the pre-mRNA transcript formed through transcription undergoes a series of enzyme-regulated modifications which includes: 5'capping,splicing,3' cleavage(polyadenylation) and RNA editing
Answer:
Explanation:
1. DNA is first transcribed into pre-mRNA, then this pre-mRNA further go series of modification, like 5' capping, 3' polyadenylation and RNA splicing.
2. Through splicing, introns are removed and exons are joined together to form a mature RNA known as mRNA.
3. If without these modifications, RNA is translated, it would encode non-functional protein because all the codons in the pre-mRNA would translated and introns would code a non-functional protein.