Unit 4 Flashcards
reproduction at the cellular level
this occurs when one cell called the parent cell divides and forms new cells called the daughter cell
unicellular organisms which consist of 1 cell do what by cellular division?
reproduce
multicellular organisms which consist of many cells do what by cellular division?
grow, heal, replace
why must cellular division occur?
to keep the cell size small because otherwise osmosis and diffusion wouldn’t be able to happen
what do daughter calls receive from the parent cell?
organelles, cytoplasm, and DNA
human bodies rely on cell division to do what
grow (1 cell ,2, 4, 8, 16, etc.)
replace worn or old cells
heal cuts, broken bones, etc.
bacteria divides every how often?
20 minutes
a human cell divides every how many hours
18-22 hours but it varies by cell. for example, bone cells take 20+ years to divide
asexual reproduction
the production of offspring from one parent cell
sexual reproduction
offspring is produced from the union of two special parental cells
where does binary fission occur?
in prokaryotes and protists
list the four types of asexual reproduction
- Binary Fission
- (Vegetative) Propagation (above ground)
- Regeneration
- Propagation (below ground)
explain vegetative propagation in strawberries
stems that grow entire plants
explain regeneration in starfish
grow parts were they have lost parts
explain propagation in potatoes
stem/”eyes” propagate new plants (clones)
gametes
specialized sex cells that joins and results in sexual reproduction
sperm
male gamete
egg/ova
female gamete
zygote
formed in the process of fertilization when the egg and sperm combine
Mitosis
it happens in somatic cells and is the cell division of eukaryotic cells (asexual)
what is the result of mitosis
each daughter cell receives an exact copy of the chromosomes present in the parent cell (the directions)
each kind of eukaryotic organism has a specific number of what I its body cells
chromosomes
somatic cells
body cells
how many chromosomes do humans have
46
how many chromosomes do goldfish have
92
corn plants are _____ because the have many chromosomes
polyploidy
how many chromosomes do mosquitos have
about 10
name the three main parts of cell replication
- chromosome replication
- organelles must be made
- must by cytoplasm growth
how long is the actual chromosome division and how long may the whole cycle take
1 hour for actual chromosome division and 20 hours for the whole cycle
interphase
the time between divisions
what two things happen during interphase
- DNA is copied
2. More organelles and cytoplasm are made
chromatin
the hereditary material (DNA and Protein)
chromosomes
short thick rods that begin to coil up and condense at the start of mitosis
chromatids
chromosomes have two
centromeres
hold together the two chromatids in a chromosome
list the phases of mitosis
prophase, metaphase, anaphase, telephase
pro
pre
what happens in prophase
- chromosomes and centrioles appear
- spindle fibers appear
- centrioles/fibers “catch” chromosomes
- 60% of mitosis=prophase