it is considered feedback mechanisms because the menstrual cycle only happens when the hormone is released, it causes the target tissues to react, that reaction is the feedback.
Answer:
C. At least five mass-extinction events have occurred during the last 500 million years.
Explanation:
- The history of mass extinct is related to the five mass extinctions that are caused over by the 350 million years n which many species have disappeared in there short geologic time.
- A massive extinction is caused in the Permian Triassic extinction event i.e about 250 mn years ago which on an estimate has killed 90% of the species.
- The Cretaceous–Paleogene extinction event that occurred over 66 million years ago is known to have wiped out the dinosaurs and many other species.
In certain organisms, like humans, there are two morphologically distinct types of gametes: (1) the male gamete (i.e. sperm cell) and (2) the female gamete (i.e. ovum). The male gamete is smaller in size and motile whereas the female gamete is several times bigger and non-motile. The haploid condition of the two gametes is essential so that at fertilization during sexual reproduction the integrity of the chromosomal number is maintained throughout generations.
Hope this helps.
From top to bottom: Earth, Saturn, Mars, Uranus, Venus, Jupiter
1. Make a goal for yourself. When you finish your fitness program(achieve your goal) you can reward yourself with like icecream or a small treat.
2. Make working out fun so that you will keep wanting to do it. For example, work-out or go to the fitness program with a friend, listen to music while doing it, etc.
3. You can make yourself motivated by watching fitness videos and basically watching things to get inspiration(trust me this works).After you watch the vids, your gonna want to keep going to the fitness program cause of all the benefits and things like that.
4. Ask a friend or someone to push you to keep going(if all else fails and you wanna quit) They will annoy you so much that it would just be better to go to the fitness program than hear them annoy you.
5. Think why your going to regret not going. This is gonna make you want to go to the fitness program.
6. Honestly if the others don't work, do it for the pictures and so that you can brag to people that you work out and stuff.
That's all I got for now. Hope it helped motivate you to keep going to that fitness program <span />
