Review your understanding of chromosomes and genes in this free article aligned to NGSS standards.
- All organisms inherit traits, or observable characteristics, from their parents. Inherited traits can include physical features, behaviors, and risks of getting certain diseases.
- Information about inherited traits is found in genes. Genes are pieces of hereditary material that are passed from parents to offspring.
- Genes are part of cell structures called chromosomes. In multicellular organisms, chromosomes are found in the nucleus of the cell.
- Each of these chromosomes contains one, long molecule of DNA, or deoxyribonucleic acid. A gene is a specific stretch of this DNA molecule.
- Each chromosome in the cell contains many genes.
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- How many genes are in a cell?(15 votes)
- How is DNA formed?(2 votes)
- DNA, or deoxyribonucleic acid, is formed through a process called DNA replication. DNA replication occurs during the cell division process known as the S phase of the cell cycle. Here are the key steps involved:
1. Initiation: The DNA double helix unwinds and separates into two strands. An enzyme called DNA helicase breaks the hydrogen bonds between the base pairs, causing the DNA strands to separate and form a replication fork.
2. Primer Binding: Primers, which are short RNA sequences, are synthesized and bind to the DNA template strands. These primers provide a starting point for DNA synthesis.
3. Elongation: DNA polymerase, an enzyme, attaches to the primer and begins synthesizing new DNA strands. It reads the template strand and adds complementary nucleotides to each growing daughter strand. Adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G), maintaining the base pairing rules.
4. Leading and Lagging Strand Synthesis: DNA replication occurs in a semi-discontinuous manner due to the antiparallel nature of the DNA strands. The leading strand is synthesized continuously in the 5' to 3' direction, while the lagging strand is synthesized discontinuously in small fragments called Okazaki fragments. These fragments are later joined together.
5. Termination: Once the entire DNA molecule has been replicated, termination signals halt the replication process. The DNA strands are fully synthesized, and the new double-stranded DNA molecules are ready for further cellular processes.
DNA replication is a highly precise and complex process that ensures accurate transmission of genetic information from one generation of cells to the next. It plays a crucial role in the growth, development, and reproduction of organisms.(20 votes)
- why do some kids look like there grandparerents?(7 votes)
- yeah like he said, you can look like just about any family member. genes get passed. even people back in the day that you were related to, just a small chance.(7 votes)
- what's the difference between Adams and molecules(2 votes)
- I think you mean atoms :)
If you are talking about Adams, be informed that all things are made up of atoms, so all Adams are made up of atoms.
If you do mean atoms, the thing is, molecules are made up of atoms. For example, a molecule may contain 2 hydrogen atoms and 1 oxygen atom. This creates a water molecule.(14 votes)
- Why do some kids look like their dad more than there mom?(5 votes)
- According to a study published in Scientific American, babies tend to look more like their fathers than their mothers. This is because fathers are less certain that a baby is theirs and are more likely to invest whatever resources they have in their own offspring. However, there is no scientific evidence that supports this claim.
Another theory suggests that genetics cause people to look and behave more like their dads than their moms. This is because children inherit half of their genetic material from each parent, and some traits are determined by genes on the sex chromosomes (X and Y). Since males have only one X chromosome, they will pass on all of their X-linked genes to their daughters but none to their sons. On the other hand, females have two X chromosomes, so they will pass on one of their X chromosomes to both their sons and daughters.
It's important to note that while some children may resemble one parent more than the other, this does not mean that they are more related to one parent than the other. Children inherit half of their genetic material from each parent, so they are equally related to both parents.(6 votes)
- if a cell can multipluy and the genes are in the cell do the genes multipluy(4 votes)
- Yes, the genes do multiply, and the genes get cloned as part of the process. As people age, however, this process gets more difficult for the body, which is why when people get older they stop growing.(6 votes)
- I see many questions about genes and appearance, so I will try to explain some. Your gender (you being male or female), is decided by your mother and father's genes, whether you have XX chromosomes, which make you female, or XY chromosomes, which make you male.
Now, along with this, your father and mother's genes which are passed onto you, do a fun sort of dance while you are in your mother's womb, to create entirely new combinations to make an entirely new person, which is you!
Why do some people look like one parent or the other? One parent may have stronger genes then the other parent, so certain traits are more visible or apparent, which is why some people look very like the parent with stronger genes, but this does not mean you are like that parent in every way because genes decide much more then appearance, just because you look like, say, your dad, doesn't mean you act like him, or have the same health he does. Some people are a mix of their parents.
Sometimes, kids look like their grandparents, or a grandparent, in this case, it's likely that your grandparent's genes, which are carried their child, which is your parent, has been passed to you, and they just strongly show in you.(6 votes)
- Thanks for sharing this. You might want to put each answer under its question, even though that could take more time. This post is technically in the wrong category, and I don’t want your post just taken down or anything.
I was wondering about how you said parents’ genes “do a fun sort of dance while you are in your mother's womb, to create entirely new combinations.” It was my understanding that one parent’s genes combine with themselves during meiosis. Then both parents’ genes combine during fertilization, which is what makes you (the zygote). The genes don’t combine while you’re in utero, but they do eventually combine to make you, right?(2 votes)
- can your DNA change through experiments(4 votes)
- Yes. DON'T try it, unless you're absolutely positively certain that you know what you're doing.(5 votes)
- Can we change the genes of a person also after the birth?(2 votes)
- Gene therapy , or somatic gene editing, changes the DNA in cells of an adult or child to treat disease, or even to try to enhance that person in some way. The changes made in these somatic (or body) cells would be permanent but would only affect the person treated.(6 votes)
- what happens if you have too little chromosomes?(4 votes)
- You cannot have "too little chromosomes." You can have different numbers* but not too little.
*In different species.(1 vote)