#Question id: 5673
#Unit 5. Developmental Biology
Species-specific sperm attraction has been documented in numerous species. In echinoderms, sperm are attracted toward eggs of their species by chemotaxis. Following statements are about chemoattraction-
A. In this process Sperm follows a gradient of a chemical secreted by the egg.
B. These oocytes control only the type of sperm they attract, but not the time at which they attract them.
C. Releasing the chemotactic factor only when the sea urchin egg has completed all of its meiotic divisions .
D. Releasing the chemotactic factor only when the sea urchin egg is in second metaphase of its meiotic division.
E. The mechanisms of chemotaxis differ among species and chemotactic molecules are different even in closely related species.
Which of the following statement are incorrect about this process?
#Question id: 12725
#Unit 13. Methods in Biology
DNA form |
Helix Direction |
Number of bases per
helix turn |
1. B
|
a. Left Handed |
i. 10 |
2. A |
b. Right Handed |
ii. 12 |
3. C | c. Left Handed |
iii. 14 |
4. Z |
d. Right Handed |
iv. 9 |
#Question id: 10368
#Unit 6. System Physiology – Plant
Free-living bacteria that are capable of fixing nitrogen are aerobic, facultative, or anaerobic. Some of the Aerobic nitrogen-fixing bacteria such as
#Question id: 565
#Unit 1. Molecules and their Interaction Relevant to Biology
A transition-state analog:
#Question id: 12522
#Unit 6. System Physiology – Plant