Question

If only a single member of a pair of chromosomes is present in a cell, it is a _____ condition and is most likely a _____ cell.



diploid; reproductive

haploid; reproductive

haploid; autosome

diploid; autosome

Answer 1

@mrdoldum

Answer 2

@hawaiiangirl Sorry, I was in the shower. Okay, what does a "pair" tell you? Humans have 23 pairs and 46 total chromosomes.

Answer 3

@hawaiiangirl Are we haploid or diploid creatures? Di means two.

Answer 4

@hawaiiangirl Hello? You here? I have to go in about 5 minutes.

Answer 5

oh ummmm idk the difference between haploid and diploid

Answer 6

@mrdoldum

Answer 7

@hawaiiangirl So, haploid and diploid and all -ploid refers to the copy number of chromosomes. This is called ploidy. You will also see it written as n, 2n (diploid), 3n(tripoloid), etc. We have pairs of chromsomes meaning that for each chromosome we have a copy. What ploidy do you think we are?

Answer 8

@hawaiiangirl Does that make sense? I know I could just give you the answer, but we are very close to merging it all together for the answer.

Answer 9

@mrdoldum diploid ?

Answer 10

@hawaiiangirl Yep. We are diploid. When we reproduce, certain cells go through meiosis and go from being diploid to haploid. Human sperm and egg have only 23 chromosomes and only a single copy of each chromosome. When they merge into a zygote and later make a fetus, we get 23 chromosomes from the sperm and 23 from the egg and become diploid again.

This reduction in the copy number of chromosomes for the gametes (name for sperm and egg cells) and then fusion of gametes from both parents to return to the "normal" copy number of chromosomes (diploid for humans) is sexual reproduction.

Answer 11

@hawaiiangirl So, something that has a pair of chromosomes is not an gamete (sperm or egg). We call these somatic cells, or cells that are for the autosome.

Answer 12

so would it be diploid reproductive or diploid autosome

Answer 13

@hawaiiangirl Diploid autosome. If it was a reproductive cell we would expect there to be a single chromosome, in this example. This is because the cell would fuse with another from a different individual to make a new diploid cell, thus reproduction.

Answer 14

@mrdoldum so what about this then
Genes that are linked together _____.



combine to form traits

result in incomplete chromosomes

form dominant traits

are found on a particular chromosome

Answer 15

@mrdoldum a combine to form traits right

Answer 16

@hawaiiangirl Not necessarily. Think about this: if the genes are linked together, could they be on separate chromsomes? Could you have two linked genes on say chromosome 3 and your X chromosome? "Linked" is the key here.

Answer 17

@hawaiiangirl It is the last one. I have to go, so I don't have to time to walk you through the full explanation so I will just post it. Linked genes may have nothing to do with each other and are linked only because they are a short distance from each other. I mean, like one is X base pairs down the chromosome sequence from the other. They get linked because crossing over events grab X base pairs, so genes that have nothing to do with each other can still be linked together simply due to their physical distance from each other. Several nasty genetic diseases are maintained because the are linked to genes that are required to survive.