Sexual Reproduction in Flowering Plants — BIOLOGY STD 12 Science — Question

1. Draw a diagram of pistil showing pollen tube growth in angiosperm and label;

1. Stigma.
2. Male gametes.
3. Micropyle.
4. Ovule.

2. Write the function of micropyle.

State where the signals for parturition arise from, in humans.

Explain Miller's experiment on origin of life with diagram.

Digrammatically represent the experimental steps in cloning and expressing an human gene (say the gene for growth hormone) into a bacterium like E. coli ?

1. You are given tall pea plants with yellow seeds whose genotypes are unknown. How would you find the genotype of these plants? Explain with the help of cross.
2. Identify a, b and c in the table given below:

S. No.	Pattern of inheritance	Monohybrid F1 phenotypic expression
i.	Co-dominance	a
ii.	b	The progeny resembled only one of the parents
iii.	Incomplete dominance	c

What is the use of aeration tank in the treatment of sewage?

The following table shows the genotypes for ABO blood grouping and their phenotypes. Fill in the gaps left in the table.

S. No.	Genotype	Blood group
i.	IA IA	A
ii.	_________________	A
iii.	IB IB	B
iv.	________________	B
v.	IA IB	_______________
vi.	_________________	O

Forests provide intangible benefits to us. Explain by taking three different areas, how.