Answer:
Book lungs
Explanation:
The horse shoe crab has a hard outer surface carapace which has the shape of a horse shoe.
It has book lungs which come in 5 sets. The lungs are usually found on the ventral side of the crab.
The book lungs acts as gills which is used in breathing when the horseshoe crab is in water . The book lungs also helps the crab to breathe on land for a certain period of time provided the lungs are moist.
 
        
             
        
        
        
Answer:
- Duplex RNA (dsRNA) can suppress the expression of a gene.
- miRNAs are short, single strands approximately 21 nucleotides long.  
- miRNAs suppress gene expression by interfering with transcription.  
- RNA interference can temporarily suppress the expression of a target gene.
Explanation:
The RNA interference (RNAi) mechanism is a naturally occurring biological process by which an organism suppresses gene expression by using sequence-specific small non-coding RNAs that are complementary to RNA (posttranscriptional silencing) or DNA (transcriptional silencing) sequences. Since its discovery, this mechanism has been exploited in molecular biology to control the expression of target genes. There are different classes of non-coding RNAs which are able to trigger RNAi gene silencing: microRNAs (miRNAs), small interfering RNAs (siRNAs), piwi-interacting RNAs (piRNAs, only present in animals), etc. During their functioning, these non-coding RNAs are loaded into the RNA-induced silencing complex (RISC) to direct them to target sequences and trigger RNAi (for example, by cleaving target mRNAs). miRNAs are short, evolutionary conserved RNAs, that associate to the RISC complex in order to trigger both transcriptional and posttranscriptional gene silencing. During their biogenesis, small non-coding RNAs are double-stranded RNA (dsRNA), but they lose a strand (the passenger strand) when associate with the RISC complex, conserving only one strand (the guide strand) that bind by complementary base pairing to target sequences (either DNA in the nucleus or RNA in the cytoplasm).
 
        
             
        
        
        
It's called the fruiting body.
        
             
        
        
        
Answer: A high-pitched, singsongy vocalization means that an animal is non-threatening, peaceful or empathetic. Dogs even employ a higher pitch with us when they're trying to get the same message across, like when they whine when they see their owner.
Explanation:
 
        
             
        
        
        
Answer:
The three main steps of PCR amplification are :
Denaturation
Annealing
Elongation
Explanation:
Polymerase Chain Reaction (PCR) can best be describes as a procedure to amplify or make copies of DNA fragments. 
The basic steps involved for PCR are :
1. Denaturation
In this step, the two complementary strands of DNA are seperated by the usage of heat. The best temperature for this procedure is 95°C.
 2. Annealing
After denaturation, each strand of DNA serves as a template foe building a new strand.  During the process of annealing, the temperature is reduced so that the primers can attach to the DNA strands. The optimum for this depends on the nature of the primers but usually the most feasible temperature is 55°C. 
3. Elongation
In this step, the DNA polymerase adds nucleotides to the primers attached to the templates. The optimum temperature For DNA polymerase to work is 72°C.