First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X and Y. He will find out if substance A is a catalyst. hope this helps :)
The part of a flowering plant that develops into a seed is the ovule.
When pollen grains land on the stigma of the correct species, they germinate. A pollen tube grows through the tissues of the flower until it reaches an ovule inside the ovary.
The nucleus of the pollen grain (male gamete) then passes along the pollen tube and joins with the nucleus of the ovule (the female gamete). This process is called fertilization.
After fertilization, the female parts of the flower develop into a fruit. The ovules become seeds and the ovary wall becomes the rest of the fruit.
Answer:
The lining of the uterus thickens
Explanation:
Only the healthiest egg will eventually mature. (On rare occasions, a woman may have two eggs mature.) The rest of the follicles will be reabsorbed into your body.
The maturing follicle sets off a surge in estrogen that thickens the lining of your uterus. This creates a nutrient-rich environment for an embryo to grow.
