Answer:
Once the embryo sac has developed, pollination has occurred, and the pollen tube has grown into the ovary to make contact with the ovule, fertilization (fusion of egg and sperm) can occur.Typically, the pollen tube reaches the embryo sac via the micropyle (Greek, mikros + pyle = small opening), or opening, in the integuments of the ovule.. There, it discharges its sperm into the embry
Explanation:
The pollen tube enters into the ovule, through the micropyle. Inside the embryo sac, the tip of the pollen tube ruptures and the 2 male gametes are set free near the egg apparatus. Inside the embryo sac, one of the 2 male gametes fuses with the egg nucleus and forms a diploid zygote. This process is called syngamy or true fertilisation.
Survivorship curve = so, first of all, it's a curve, as in a graph.
It describes "survivorship" - the rate of survival, in other words: out of 100 organisms that are born, how many survive. This rate is different among species, for example, most humans live out to most of their life span, and almost all can survive well beyond a reproductive age.
However, in frogs for example, many many individuals are born, but only few can survive to adulthood: most die very young, before reproductive age.
So if you hear about a new species: let's say dogs, and you want to know how long they would live, you would look at their sirvivorship curve (and in some breeds of dogs, those that are likely not to be in shelters, but in homes, the survivorship curve would be similar as in humans: almost all individuals born can live long.
An example of a population in which evolution could take place in a relatively short period of time could be pathogenic bacteria exposed to antibiotics.
Answer: Option A
<u>Explanation:</u>
Evolution if takes place within a short period of time say the next generation that is called as micro evolution. This is caused when a specific organism exposed in a different environment at once modifies its genes to suit the new environment. This phenomenon can be very well seen in the pathogenic bacteria which are exposed to antibiotics.
When an antibiotic is prescribed to bacteria initially it nullifies its effect by destroying it. When continuously exposed to a certain antibiotic some bacteria dies but there are few which becomes resistant to it and survives. This on the other hand multiplies producing a generation that can’t be touched by the antibiotic.
