2 then 1 then 3 you're welcome
B.
The Radio-ulna and digits of most primates and animals represents a homologous structure
An example of another internal structure is the genes.
The homologous chromosomes have the same genes in common. Each cell has at least two sets of chromosomes which one comes from one’s father also called as paternal chromosome and mother, called as the maternal chromosomes. These chromosomes are what makes the child obtain the characters and may depend on the traits the parents possess. Homologous chromosomes are not duplicated chromosomes or identical however, they are analogous or similar. The alleles for a specific characteristics isn’t the same but the same genes are in the same order.<span> </span>
YH HYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY
The answer is horizontal gene transfer.
Horizontal gene transfer enables gene flow between genomes of two organisms. It is a common process between different species of <span>prokaryotes and even, between prokaryotes and eukaryotes. </span>When trying to reconstruct evolution and phylogenetic relationship, scientists face some difficulties because they cannot say the common gene transfer with the horizontal one.
Answer:
Cytotoxic T cells
Explanation:
Perforin is the cytosolic protein and upon degranulation forms pores in the target cell. Perforin protein helps in the transport of water and ions.
Perforin is present in the granules of cytotoxic T cells. These cells have the ability to kill virus infected cells and cancer cells. Cytotoxic T cells bind with the class 1 MHC molecules. These cells are also known as CD8+ T cells.
Thus, the correct answer is option (A).