Studied by 30 peopleWhat determines a cell's size?
DNA, diffusion, and surface-area-to-volume ratio.
As you grow from a baby to a teenager, do your cells get bigger or do you gain more cells?
More cells are gained.
Why do cells divide into more cells rather than continue to grow?
Info shortage and exchanging materials.
Why does info shortage play a role in motivating cells to divide into more cells?
Info shortage plays a role because as the cell gets bigger, DNA stays the same. DNA demands cannot support the protein needs of large cells.
Why does the exchange of materials play a role in motivating cells to divide into more cells?
The exchange of materials plays a role because large surface area slows the exchange of materials in and out of the cell. Large cells cannot obtain enough nutrients (O2, etc).
Surface area (SA) of the membrane determines?
Determines the rate of exchange of materials.
Volume (V) of the cell determines?
Determines the rate material is used and discarded.
As the size of a cell increases?
As the size increases, its volume increases faster than its surface area, decreasing the ratio of SA to V.
If a cell becomes too large?
If it becomes too large, nutrients and wastes cannot exchange fast enough through the membrane. Therefore, smaller size allows for efficient movement of materials in and out of the cell.
Instead of growing too large, cells?
Instead of growing too large, cells divide in half to increase the SA:V ratio.
All organisms grow and?
Grow and change; worn out tissues are repaired or replaced by newly produced cells.
Why does each daughter cell get its own complete copy of the DNA?
Each daughter cell gets this so there is no information shortage.
What are the characteristics of asexual reproduction?
One parent; all structures in the cell are copied, and then the parent cell divides, making two exact copies.
Which cells reproduce asexually?
Most cells in your body and single-celled organisms do this.
Single-celled organisms can produce new organisms by?
By cell division (fission) or budding.
What are some examples of single-celled organisms asexually reproducing?
Some examples are bacteria fission and yeast.
Multicellular organisms can reproduce asexually by?
By vegetative propagation or again, budding.
What are some examples of multicellular organisms asexually reproducing?
Some examples are hydras and strawberry bushes.
What are the characteristics of sexual reproduction?
Involves fusion of 2 separate parent cells; genetic information combines, forms offspring different from both parents.
Who reproduces sexually?
Most animals and plants reproduce this way.
Species survive by?
By reproduction.
Species better suited to their environment survive?
Survive better.
What are the differences between asexual and sexual reproduction?
Asexual reproduction is fast, involves organisms that are all identical, and is an advantage if the conditions are favorable and a disadvantage if they are not. Sexual reproduction, meanwhile, requires more time and provides genetic diversity because DNA comes from both parent cells.
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