The male
human has a sperm cell and the female has an egg cell. The cells from the male
and female that combine to form a zygote are called gametes. The human sperm
and egg cells each contain 23 chromosomes. . A combination of gametes forms a
zygote with 46 chromosomes. The type of cell division that produces gametes
with half the normal chromosome number is the meiosis. Meiosis is the type of
cell division used in sexual reproduction. It will occur in the testes and
ovaries.<span>Chromosomes get
shuffled when eggs and sperm are made. Though most adult cells contain two sets
of chromosomes, sperm and egg cells are different. These special cells have
just one chromosome from each pair. Which chromosome they get from each pair is
random, making each sperm or egg cell unique. There is also a bit of mixing
before the chromosomes are sorted into individual sperm or egg cells.
Chromosomes from each pair in a mother or father, respectively, make contact
and exchange pieces of DNA, creating hybrid chromosomes. </span>
I think it is rising sea level
In order to survive the winter, monarch butterflies "migrate to warmer areas".
<u>Option: B</u>
<u>Explanation:</u>
- The survival for Monarch butterflies is not possible in any of the United States 'cold winters, therefore they are needed to migrate south and west every autumn to avoid the cold temperatures.
- This species migration usually begins around every year in October, but may begin quicker if the weather turns cold earlier than that.
- Thus they spend their winter hibernation all year round in Mexico and some areas of Southern California where the temperature is warmer.
- If the monarch stays in the Eastern states, typically east of the Rocky Mountains, then they will migrate to Mexico and hibernate in <em>oyamel fir</em> trees.
Answer:
to derive energy from the sun
