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#(C)# All animals reproduce sexually only.


All the other options are quite correct about animals. Because organisms belonging to Kingdom Animalia are Eukaryotes, heterotrophs and most are motile.

But all animals undergo only sexual reproduction is something to which the answer is No! Because there are some animals who are capable to undergo both sexual and asexual reproduction. For example: Members of phylum Coelenterata or Cnidaria, Platyhelminthes #&# Porifera(containing the most primitive animals) reproduce by both sexual and asexual means.

Let's take hydra as an example: Hydra is a coelenterate that can reproduce asexually by a process called budding. The bud grows on the outer surface of body. This bud later separate from the parent hydra and develops into a new individual.


Hope it helps!


Assuming that colour blindness is the recessive trait, 100% of the males will be color blind, and 0% of the females will be.


Since the F1 progeny refer to the direct descendants:

Let #N# denote a dominant allele, and #n# a recessive allele.

If the father is normal, he has genotype #X^NY#.
If the mother is colour blind, she is homozygous recessive, with genotype #X^nX^n#.

Thus, all male children will inherit the #Y# chromosome from the father and the recessive #X^n# allele (colour blindness) from the mother. Thus they will all be colour blind.

On the other hand, all female children will inherit the dominant #X^N# allele from the father, thus making them #X^NX^n#, heterozygous normal (carriers). Thus, they themselves will not be colour blind, but they do have a chance of passing down the trait for colour blindness, i.e. having children who are colour blind.

Fancy words used:
Allele = version of a gene
Homozygous = both copies of the gene are the same, e.g. #X^nX^n#
Heterozygous = the two copies are different, e.g. #X^NX^n#


Usually through the sun for plants, and animals eat the plants.


Most, if not all plants are producers, and they make their own food using sunlight and raw materials, through a process called "photosynthesis". In return, the products are water #(H_2O)# and glucose #(C_6H_12O_6)#, which are then broken down by cellular respiration into pyruvate #(C_3H_3O_3^-)#, and then #ATP# which contains tons of energy.

Animals however, are usually not producers, and therefore have to eat other organisms in order to gain energy. This can be explained through trophic levels, but animals usually get little amounts of energy in an ecosystem.

Here is a picture of the trophic levels:


I hope this helps!


Linked genes are on the same chromosome.


Some genes are "linked" to each other because you inherit them together.
Inherit one, inherit the other.

You inherit them together because they are on the same chromosome, and when the gametes are formed by meiosis, they receive the entire chromosome from the original cell.

However, it turns out that when the chromosome pairs line up during meiosis, they often swap whole sections.

This swapping is called "crossing over," which disrupts the linkage between genes by "unlinking" them.

Here's an image showing crossing over

enter image source here

After a section of the chromosome crosses over to the homologous chromosome, the genes at the end are no longer linked with the genes on the rest of the chromosome.

Crossing over lets us map the location of genes on their chromosomes by finding the sequence of genes along the length of a chromosome.

The further apart the linked genes are on the chromosome, the more likely it is that a break will occur in between them.

But when two linked genes are close to each other, it is less likely that a random break will happen between them.

So by studying the frequency of crossing over between pairs of linked genes, scientists were able to determine if they were close or distant. The more common the crossing over, the more distant they are on the chromosome.

Here is an image of that idea
enter image source here


See Below


There are a lot of parts and pieces involved in the electron transport chain, but with respect to Oxygen, the simple answer is Oxygen is the place where the electrons go, it i sthe thing that gets reduced.

I'm not going to link to all the membranes and chemical reactions, but rather just refer to something simple like a carbon in a typical fat.
#-CH_2-# this is what a carbon in a fat looks like (in general).
As that carbon sits now, it has a ~ -2 oxidation state.

When you exhale that carbon as #CO_2# (after cellular respiration and oxidative phosphorylation, etc), the C has a +4 oxidation state.

That means for the Carbon:
#C^-2 = C^"+4" + 6e^-#
Those 6 electrons have to go somewhere. And they go onto Oxygen!
You breath in elemental #O_2# with a zero oxidation number. That carbon above turns into a #CO_2# and basically 1 water, #H_2O#
So that Carbon needs to get rid of 6 electrons...and in #CO_2#, each Oxygen has a -2 oxidation state (from zero to -2), and the water oxygen has a -2 oxidation state (from zero to -2). So when that Carbon in the fat gets oxidized and you breath it out as #CO_2#.
The place were those 6 electrons went is onto the #O_2# that you breathed in (and breathed out as #CO_2# and maybe some water (simplistically speaking)


Cells with the full set of chromosomes are #"diploid somatic cells."#


Somatic cells are the cells that make up the vast majority of the body.

Somatic cells each have the complete set of chromosomes.

In humans, that means that the somatic cells have #46# chromosomes each #-# #23# pairs, one set of #23# from each parent, for a total of #46.#

In order to maintain the correct number of chromosomes when the egg cell and sperm cell combine, the chromosome number in the gametes is cut in half during #"meiosis"# (the "reduction" division.)

Somatic cells, with the full set of chromosomes are #diploid,"# with the #2n# chromosome number.

Gametes, with one half the full number of chromosomes, are #"haploid,"# with the #1n# chromosome number.

During fertilization, the somatic cells' #2n  "diploid"# chromosome number is restored when both of the #1n  "haploid"# gametes fuse with each other.

Here's an image of this process:
The #"diploid"# #(2n)# cells are #"somatic"# cells. and the #"haploid"  (1n)# cells are the gametes.

enter image source here

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