The right answer is vein (it contains blood and has valves).
The infra-cardiac veins of small and medium caliber possess this system of fight against gravity. The valves consist of a dense connective tissue, surmounted by endothelial cells, corresponding to a fold of the intima. They allow blood circulation in the sense organ / heart but prevent venous reflux.
Answer: d. Predators avoid prey that are in their prime in order to maintain a high reproductive rate in the prey population, and hence 'grow' prey for the future.
Explanation:
A predator can be define as an organism superior and strong enough to kill inferior and weaker organism. This organism kill other organism to obtain it as food. A prey is an organism which is weak and cannot defend itself from the attack of the superior organism.
d. is the correct option. This is because the predators do not bother about the age and strength of the prey. They attack over them whether the prey is weak , young, prime, or old and try to obtain it as food.
Because it codes for specific proteins and contains the genetic instructions needed in order for an organism to survive, develop and reproduce
Answer:
deoxyribose
Explanation:
A phosphate backbone is the portion of the DNA double helix that provides structural support to the molecule. DNA consists of two strands that wind around each other like a twisted ladder. Each strand has a backbone made of alternating sugar (deoxyribose) and phosphate groups.
I hope that this helped you ;)
