1. Assertion: Mother may be a carrier for haemophilia. Reason: The father is always a carrier for haemophilia.
(a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.
(b) Both Assertion and Reason are true but the Reason is not the correct explanation of the Assertion.
(c) Assertion is true, but the Reason is false.
(d) Assertion is false, but the Reason is true.

Astudy by solloch and et. al., in 2017, gives the map above which shows the frequency of alleles with a ccr5-delta32 mutations over 87 different countries. this mutation deletes the presence of a co-receptor (ccr5) on the outside of human t-cells (lymphocytes). some viruses, such as the one responsible for the black death and human immunodeficiency virus (hiv), require this receptor for attachment to host cells during the infection process. the black death was an epidemic that passed over northern europe during the 14th century killing nearly 60% of europeans. according to this information, which explanation best explains why northern europeans show a greater immunity for hiv than some other parts of the world?

How does the human body lever work?

Communication and transportation have improved as a result of scientific advancements. select the best answer from the choices provided of mark this and return save and exit next