1
Q
Cell Life Cycle
A
Constitutes Cell growth and reproduction
2
Q
Cell growth
A
- genetic information (in DNA) codes for the structural and function al proteins needed for cell survival
- Interphase
3
Q
Cell reproduction
A
genetic information is passed from one generation to the next (most often: mitosis)
4
Q
Centromere
A
Protein that holds chromatids together
5
Q
Chromosome
A
one long piece of DNA
6
Q
Sister Chromatids
A
two Chromatids held together by a Centromere
7
Q
Interphase
A
- growth phase of the cell life cycle can be subdivided into
- G1(first growth phase)
- S (the DNA synthesis phase)
- G2 (the second growth phase)
8
Q
G1
A
- First step of Interphase
- production of cytoplasm, more cell material is made
- Right after division so the cell is (recovering) from the division
9
Q
S
A
The DNA synthesis phase
- Replication of the genome; done by base paring
- Chromosome duplication
10
Q
G2
A
The second growth phase
-in preparation for the next cell division
11
Q
Mitosis
A
- Cell division that results in 2 genetically identical daughter cells
- Used for growth, repair, replacement, asexual reproduction
12
Q
Meiosis
A
- Cell division that results in 4 haploid, genetically unique daughter cells
- Used for production of gametes (sexual reproduction)
13
Q
Prophase
A
First Stage of Mitosis
- DNA coils up into chromosomes
- Nuclear envelope begins to decompose
- Centrioles/microtubules separate and begin building spindle fibers
14
Q
Metaphase
A
Second Stage of Mitosis
- Chromosomes line up in the middle of the cell
- Spindle fibers attach to the chromosome at the centromere
15
Q
Anaphase
A
3rd stage of Mitosis
- the spindle fibers pull the chromosomes apart at the centromere
- the split chromosomes migrate towards opposite sides of the cell
16
Q
Telophase
A
4th stage of mitosis
- The chromosomes begin to uncoil
- Nuclear envelope reforms
- Spindle fibers decompose
- Cytokinesis occurs
17
Q
Cytokinesis
A
Part of Telophase (4th stage of Mitosis)
- When the plasma membrane pulls together and pinches off into two cells
- Cleavage furrow
18
Q
Cell Growth consists of what phase? What three sub-phases?
A
Interphase:
- G1
- S
- G2
19
Q
Mitosis consists of what four stages?
A
- Prophase
- Metaphase
- Anaphase
- Telophase
20
Q
What sub-phase occurs during Telophase
A
Cytokinesis
21
Q
Humans Chromosomes
A
46 total chromosomes
- 23 pairs (diploid) one of each chromosome is inherited from each parent
- 1-22 are called autosome (not sex cells) and are numbered by size
- Last pair consists of an XX(female) or XY(male)
22
Q
Haploid Gametes vs. Diploid Zygote
A
Diploid Zygote (2n=46) Haploid Gametes (n=23) ex. Egg cell, Sperm Cell (in Humans)
23
Q
Meiosis
A
- Diploid parent cell becomes 4 haploid daughter cells
- This happens across 2 divisions
- Meiosis I
- Meiosis II
24
Q
Meiosis I consists of what 4 phases
A
Homologous Chromosomes separate Creates diversity -Prophase I -Metaphase I -Anaphase I -Telophase I
25
Meiosis II consists of what 4 phases
```
Sister chromosomes separate
Turns diploid to Haploid cells
-Prophase II
-Metaphase II
-Anaphase II
-Telophase II
```
26
Prophase I
the chromosomes recombine in a process called crossing over
27
Metaphase I
the chromosomes are independently assorted
28
Nondisjunction
- when a pair of chromosomes fails to separate during meiosis
- Chromosomal abnormalities are the cause of certain congenital disorders
29
congenital
Born with
30
Gametes
sexual reproduction cells
31
Traits are the result of inherited sequences of DNA called ______. They can have variations called _______.
ex. The _____ for flower color in peas has 2 ______.
Gene. Alleles
32
Diploid organisms carry ____ copies of each Gene
2 copies.
| If you have two identical copies you are said to be Homozygous for that trait
33
Homozygous
Has 2 identical alleles for a trait
34
Heterozygous
2 different alleles for a trait
35
What happens when an organism is heterozygous for a trait
They have two different alleles often one allele is expressed. this is the dominate allele
36
How often are dominant alleles expressed?
Always
37
Ones Genotype is
Their combination of Allele
38
Ones phenotype
What you can see
| Pheno- greek for eye
39
Law of segregation
During meiosis, the chromosomes pairs divide and the gametes are haploid.
- alleles in an organism are segregated in the gametes
- offspring only inherit one allele from each parent ( resulting in a diploid zygote
40
Law of independent assortment:
- Pairs or alleles sort independently of each other
| - The inheritance of one trait has no effect on the inheritance of the other
41
Law of Dominance
Dominant alleles are always expressed and the un expressed trait is recessive
42
Pedigree
Family tree showing the genetic history
Biology 1
flashcards
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