Answer:
Nematocysts, the most widely used term to describe the “stinging capsules” characteristic of the phylum Cnidaria, constitute the best-studied and most diverse group of cnidae, the secretory products of cnidocytes. All cnidae consist of a collagenous capsule containing an eversible tubule.
Answer:
spindle fibres
Explanation:
during mitosis/meiosis spindle fibres form and pull the chromosomes to each end
Living organisms need DNA because the DNA is the genetic code for living organisms. It determines the characteristics of the organism.
I think it isn't right to claim that an attribute developed so the species included can survive better, qualities advance since people with that characteristic survive better and duplicate more.
I hope the answer will help you.
Answer:
Question: Two requirements for gas exchange which are accomplished by the gills in a fish include:
1. Water flowing in opposite directions across the gill lamellae for gas exchange, in other words, respiration is experienced by the fish.
2. The fish allows water through its mouth, then forces the water to drain through the gills supporting gill lamellae, and enhancing gas exchange.
Question: How does their structure help to satisfy these requirements?
1. The rows of gill filaments with numerous folds through diffusion makes sure oxygen from the water moves from a place of more concentration to the blood of the fish which has less concentration causing the removal of carbon dioxide.
2. The large surface area of the gill means it has to maximize the low percentage of dissolved oxygen in the water compared to the higher percentage of oxygen in the air makes it possible for water to pass through the mouth and empty through the gills after the mouth is closed.
