Answer:
Fertilization
Explanation:
Egg and sperm are cells known as gametes produced by the GAMETOPHYTE of a sexually-reproducing organism via meiosis. Since egg and sperm cells are produced through meiotic division, their chromosomal number is reduced by half of the parental organism. Hence, sperms and eggs are haploid cells (n) produced by a diploid organism (2n).
Sperm is the male gamete while egg is the female gamete. These two haploid gametes fuse in a process called FERTILIZATION, to produce a diploid ZYGOTE that eventually grows into the diploid structure of the organism called SPOROPHYTE. This system of reproduction called ALTERNATION OF GENERATIONS is used by lower and higher plants.
Answer:
D. Calcium ions.
Explanation:
Here we are talking about the mechanism of muscle contraction. The most accepted theory of muscle contraction is sliding filament theory. It was given by Huxley and Huxley. During the process actin filaments slides over myosin filament by forming cross bridges. The sequence of events are as follows:
a. An action potential propagates through the motor nerve and reach the nerve endings on the muscle fiber at neuro-muscular junction.
b. Neurotransmitter called acetylcholine is released by the nerve endings.
c. Acetylcholine binds to the receptors on muscle fiber and opens the gated channels which causes flow of Na+ ions into the muscle fiber.
d. This influx of sodium ions initiates an action potential in the muscle fiber which reaches the T- tubules or transverse tubules. Here it causes the sarcoplasmic reticulum to release large amounts of calcium ion.
e. Calcium ions are responsible for initiating the attractive forces between actin and myosin filaments. Cross bridges are formed, actin slides over myosin causing the contraction of muscle.
Answer:
4.A number line going from 30 to 34. An open circle is at 32. Everything to the left of the circle is shaded.
Explanation:
It is given that the three-fourths of the employees at a bookstore came to a staff meeting. Less than 24 employees were at the meeting.
Let the total number employees be e.
Three fourth of the total employees is e, the total number of employees at the meeting were less than 24.
e < 24
Multiply 4 both sides.
ex 4 < 24×4
3e < 96
Divide both sides by 3.
e < 32
Therefore the value of e is less than 32.
In a number line as we approach towards left the the value of integers decreases.
Since the value of e is less than 32, therefore the solution graph is from negative infinity to 32.
Since 32 is not included in the solution set, therefore there is an open circle on 32.
By discovering a synthetic cell . I hope you have a great day
