It seems that you have missed to include the necessary options for this question so I had to look for it. Here is the answer. The one that lymphoid cells traps antigens and transport them to lymph nodes are the T LYMPHOCYTES. Hope this answers your question.
The red-legged frog breeds in ephemeral ponds from January through March. Its relative, the bullfrog, breeds in permanent ponds from late March through May. There are two pre-mating isolation mechanism at play here,
1. Ecological isolation: The habitats are different, hence the individuals of both the species do not meet. Ephemeral ponds are temporary ponds that develop during rainy days, while the permanent ponds are full of water throughout the year.
2. Temporal isolation: The time of mating is different for both the species to avoid contact between the individuals of closely related species. Red-legged frogs mate in January to March slot and the bullfrog in the March to May slot.
Answer:
There are about 300 different types of species, but we've not explored even more than 50% of the ocean
Explanation:
All the cells in a person's body have the same DNA and the same genes. However, the difference between cells in different tissues and organs is that the "expression" of the genes differs between cells. Expression means that the message from the DNA is being copied and made into protein.
Answer: Point mutation is easily reversible, thus non-lethal
Explanation:
Point mutation is caused by exchange of a single nucleotide for another. These change is called
1) Transition (when a purine base substitute another purine base, or pyrimidine bases substitute each other)
2) Transversion (when a purine base substitute a pyrimidine base).
However, note that a point mutation can be easily reversed by another point mutation; so, the claim that a nucleotide difference in the Hsr12 gene caused the human disease is inaccurate
