Reproduction in organisms — BIOLOGY STD 12 Science — Question

List the changes that the primary ooctye undergoes in the tertiary follicular stage in the human ovary.

When do the oogenesis and the spermatogenesis initiate in human females and males respectively?

With an example explain lattitude gradient, as a pattern of biodiversity.

Construct an ideal pyramid of energy when 10,00000 J of sunlight is available. Label all its levels.

The following graph represents the organismic response to certain environmental condition (e.g. temperature):

1. Which one of these, 'a' or 'b', depicts conformers?
2. What does the other line graph depict?
3. How do these organisms differ from each other with reference to homeostasis?
4. Mention the category to which humans belong.

Observe the figure A and B given below and answer the following questions:

1. The power generation by the above two methods is non-polluting True/False.
2. List any two applications of solar energy.
3. What is a photovoltaic cell?

In a pea plant, smooth seed coat is dominant over wrinkled seed coat. What will be the expected ratio of phenotypes of the offspring in a cross between:

1. Heterozygous smooth × Heterozygous smooth
2. Heterozygous smooth × Homozygous wrinkled
3. Heterozygous smooth × Homozygous smooth

What is the fate of trophoblast in mammalian embryo?

Study the table showing the population interaction between species Z and Y respectively. Assign the appropriate +/– signs for A,B,D,E and respective interactions for C and F.

Humans benefit from diversity of life. Give two examples.