Question
Distinguish between: Zona pellucida and Corona radiata.
| Zona pellucida | Corona radiata |
| 1. Zona pellucida is inner, thin and transparent layer surrounding the secondary oocyte. | 1. Corona radiata is the outer thick layer surrounding the secondary oocyte. |
| 2. Zona pellucida is a non-cellular layer. | 2. Corona radiata is a cellular layer. |
| 3. Zona pellucida is secreted by the ovum itself. | 3. Corona radiata is formed by follicular cells which are glued together by hyaluronic acid. |
| 4. Zona pellucida is retained for more time after fertilization till the ovum gets implanted in the uterus. | 4. Corona radiata is retained till the ovum gets fertilized. |
| 5. Zona pellucida is digested by zona lysine or acrosin at the time of fertilization. | 5. Corona radiata is digested by hyaluronidase enzyme at the time of fertilization. |
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| Column I [Phases] | Column II [Hormonal changes] |
| (1) Menstrual phase | (a) Rapid secretion of LH |
| (2) Proliferative phase | (b) Increased level of FSH and estrogen |
| (3) Ovulatory phase | (c) Increased level of progesterone |
| (4) Secretory phase | (d) Decrease in progesterone and estrogen |
| S. No | A | B | C | D |
| (a) | Chalaza | Female gametophyte | Embryo sac | Micropyle |
| (b) | Chalaza | NuceIIus | Embryo sac | Micropyle |
| (c) | Micropyle | Egg | Embryo sac | Chalaza |
| (d) | Micropyle | Nucellus | Embryo sac | Chalaza |
| Column A | Column B |
| (1) Organism | (a) Large unit with specific climatic zone |
| (2) Population | (b) Different species in particular area |
| (3) Community | (c) Same species in a geographical area |
| (4) Biome | (d) Basic unit of ecological hierarchy |
|
S. No
|
Structure of X
|
Stamens
|
|
(a)
|
Abundant and light
|
Pendulous
|
|
(b)
|
Rough surfaces
|
Non-pendulous
|
|
(c)
|
Light and sticky
|
Pendulous
|
|
(d)
|
Coarse and sticky
|
Protrude outside the flower
|

| Restriction enzyme | Recognition sequence |
| (1) Alu I | (a) 5′ G-A-A-T-T-C 3′ 3′ C-T-T-A-A-G 5’ |
| (2) Bam HI | (b) 5′ G-T-C-G-A-C3′ 3′ C-A-G-C-T-G 5′ |
| (3) Eco RI | (c) 5′ A-G-C-T 3′ 3′ T-C-G-A5′ |
| (4) Hind II | (d) 5′ G-G-A-T-T-C 3′ 3′ C-C-T-A-A-G 5′ |