? 發問於 科學及數學生物學 · 7 年前

S1 cell and human reproduction

help me fill in the bank

? mean me unkmow

1.? occurs when a sperm and egg join togeter.

2.Fertilization usually occurs in the ?.

3.? is the eybryo attaches itself to the uterus lining.

4.Watery liquid protects the foetus from ?.

5.?,?,? and ? are exchanged through the placenta.

6.An absence of ? is the most obvious sign of pregnancy.

7A.How many sperms are involved? identical/non-identical twins

7B.How many eggs are involved? identical/non-identical twins

7C.Do the twins have same genetic material identical/non-identical twins

8.? and ? are one of the signs of sexful maturity in girls and boys respectively

2 個解答

評分
  • ?
    Lv 5
    7 年前
    最愛解答

    1. Fertilization

    2. oviducts

    3. Implantation

    4. shock

    5. Oxygen, food, carbon dioxide and waste products

    6. menstruation

    7A. identical:1

    non-identical:2

    7B. identical:1

    non-identical:2

    7C. identical:yes

    non-identical:no

    8. Menstruation and wet dreams

  • 7 年前

    想當年...我溫呢課溫到喪屍感款.....所以你都要努力呀..........

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