(a) Mention the cause and the body system affected by ADA deficiency in humans.
(b) Name the vector used for transferring ADA-DNA into the recipient cells in humans. Name the recipient cells.Cleistogamous flowers are flowers which do not open at all.
Advantage of cleistogamy:
Cleistogamous flowers produce assured seed-set even in the absence of pollinators that is they can propagate themselves even under unfavourable condition.
Disadvantage of cleistogamy:
Cleistogamous flowers undergo self pollination only, which reduces the chances of variation and evolution of genetically superior progeny.
(a) Name the group of viruses responsible for causing AIDS in humans. Why are these viruses so named?
(b) List any two ways of transmission of HIV infection in humans, other than sexual contact.
(a) Draw a neat labelled diagram of a nucleosome.
(b) Mention what enables histones to acquire a positive charge.