Answer:
The correct answer would be C) It increases survival for cuckoos, but decreases survival of the other birds.
The host chicks often face lots of competition from the cuckoo chicks in terms of food as well as space. It makes it difficult for the host chicks to survive.
It has also been found that cuckoo chicks beg to be fed more intensely due to which host chick die due to starvation.
In addition, in some species of cuckoo, cuckoo chicks remove host eggs from the nest within few days of hatching.
Answer:
Helper T cells are arguably the most important cells in adaptive immunity, as they are required for almost all adaptive immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.
Explanation:
Helper T cells become activated when they are presented with peptide antigens by MHC class II molecules, which are expressed on the surface of antigen-presenting cells (APCs). Once activated, they divide rapidly and secrete cytokines that regulate or assist the immune response.
The egg is big but it is mainly the protein and fat ! the white part is albumin protein and the yolk is fat stored for baby !
Explanation:
The oldest fossil evidence of seed plants is of Late Devonian age, and they appear to have evolved out of an earlier group known as the progymnosperms. These early seed plants ranged from trees to small, rambling shrubs; like most early progymnosperms, they were woody plants with fern-like foliage.
