BIOL10210 Lecture Notes - Lecture 10: Wood Lemming, Echiura, Mycosis
Sex chromosomes pair at meiosis i. meiosis ii separate. 50% of sperm contain x or y chromosome. Other things than just gender attached to sex chromosomes like male pattern baldness. So we can say that meiosis promotes a sex ratio of 50:50. If the sexes have roughly equal opportunities to mate, natural selection will hold the sex ratio very near 50:50: odds reset each time, some sort of pertinacity, favoring a gamete over another, in female genitalia. Focus entirely on males because of sexism in science. Males more likely to die, especially during famine, Male sterility caused by selfish mtdna in many higher plants (brassica napus) includes things like radishes, cabbage, broccoli etc. Another one has male part repressed, natural occurrence cutoff to prevent inbreeding, biological level/level of gametes. Parasite wolbachia which can kill males, turn males into females or cause females to become parthe(cid:374)oge(cid:374)eti(cid:272). (cid:894)(cid:271)e(cid:272)o(cid:373)e a t(cid:455)pe of fe(cid:373)ale that does(cid:374)"t (cid:374)eed a (cid:373)ale to reprodu(cid:272)e(cid:895).