Bài 14. Thân dài ra do đâu ?

BAI 14: THAN DAI RA DO DAU?
GIAO VIEN: LE BOI NGOC
HOC SINH:TRAN THI MINH NGOC
PHAN 1:SU DAI RA CUA THAN
-Gieo hat dau vao khay co cat am cho den khi cay ra la that thu nhat.
-Chon 6 cay dau cao bang nhau.Ngat ngon 3 cay(ngat tu doan co 2 la that)
-Sau 3 ngay do lai chieu cao cua 3 cay ngat ngon va 3 cay khong ngat ngon.Tinh chieu cao binh quan cua moi nhom.
Phan lam bai:
Ghi ket qua da do duoc vao bang duoi day:

Hinh:
Dau :


Phan thao luan:
-So sanh chieu cao cua hai nhom cay trong thi nghiem:ngat ngon va khong ngat ngon.
-Tu thi nghiem tren, hay cho biet than cay dai ra do bo phan nao?
-*Xem lai bai 8”Su lon len va phan chia te bao “,giai thich vi sao than dai ra duoc?
Phan nen biet:
+Su dai ra cua than cac loai cay khac nhau thi khong giong nhau:
-Cay than go lon cham hon, nhung song lau nam nen nhieu cay cao, to nhu bach dan, cho, lim,…
-Cay truong thanh khi bam ngon se phat trien nhieu choi, hoa, qua, con khi tia canh cay tap trung phat trien chieu cao.
Phan 2:Giai thich nhung hien truong thuc te:
-Khi trong dau, bong, ca phe, truong khi cay ra hoa, tao qua, nguoi ta thuong ngat ngon.
-Trong cay lay go (bach dan, lim), lay soi(gai, day), nguoi ta thuong tia canh xau, canh bi sau ma khong bam ngon.
Cau hoi:
Hay giai thich vi sao nguoi ta lai lam nhu the?

Bai tap:
Than dai ra do:
Su lon len va phan chia te bao
Choi ngon
Mo phan sinh ngon
Su phan chia te bao o mo phan sinh ngon.
Phan ghi nho:
Than cay dai ra do su phan chia te bao o mo phan sinh ngon.
De tang nang suat cay trong, tuy tung loai cay ma bam ngon hoac tia canh vao nhung giai doan thich hop.
Cau hoi:
Hay danh dau x vao nhung cay co than dai ra nhanh:
A)Mong toi d)Dau van
b)Muop e)Tre
c)Oi g)Mit
h)Bi i)Nhan
k)Bach dan
Cau hoi:
Hay danh dau x vao nhung cay khi trongduoc ngat ngon de cho thu hoach cao:
A)Mong toi d)Dua
B)Rau muong e)Che
C)Rau day