6. Şemada üreme hücrelerinin oluşturulmasından, embriyonun oluşumuna kadar olan aşamalar yer al- 7. SINIF
FEN BİLİMLERİ
maktadır.
Sperm
Embriyo
Zigot
Yumurta
Buna göre,
1. Sperm ve yumurtanın oluşumu, mayoz bölünme sayesinde gerçekleşmiştir.
II. Zigotun embriyoyu oluşturması sürecinde hücre sayısı zamanla artmıştır.
III. Sperm, yumurta ve zigot aynı kalıtsal özelliktedir.
ifadelerinden hangileri doğrudur?
A) Yalnız!
B) I ve II
Il ve III
I, II ve III​

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!

i dont know it at allnow im just getting points at this pint

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.