Question | Answer |
Why is sexual reproduction advantageous? | It gives genetic variation, heritable traits, unique combination of genes, production of offspring that are alike. |
what is the purpose of cell division? | o duplicate themselves
repair of tissue damages
growth of organs
division of zygote
to reproduce |
how many genes does a prokaryote have? | approximately 3,000 |
how is dna arranged in a prokaryote cell? | circular dna model |
sister chromatids | 2 identical copies of dna molecules
they are cohesive which means the proteins hold he chromatids together |
how many chromosomes does a haploid and a diploid have? | A haploid has 23
a diploid has 46 |
what are the two gametes? | egg and sperm |
number of daughter cells after meiosis 2 | 4 |
what is he longest stage of meiosis? | prophase 1 |
density dependent inhibition | it is a single layer of cells.
an example is cells divide to repair damaged tissues until touches other side then stops. |
growth factors | it stimulates growth of cells, uses in density packed environment, stops division when growth factors are used up. when cut is healed growth factors used up and issue repair discontinues. |
when checkpoints occur in the cell cycle and how many there are. | There are 3 checkpoints and they are G1,G2, and M phase. |
SIGNALING DIVISION | G1 is the signaling division |
percentage of time a cell divides | 10% |
organs that cell division occurs in | the liver, the skin, and the intestines,
spinal cells do not divide or repair once damaged. |
tumor surpessor gene | p53 and RB protein |
how tumors can form | cell layers build up on top of each other when "not told" to stop. |
malignant tumors vs. benign tumors | ones a cancer tumor and one isn't |
chemotherapy | chemotherapy uses drugs that disrupt cell cycle. It uses taxol (from yellow tree) which freezes the mitotic spindle. it uses vinblastine (periwinkle plant) which prevents spindle from forming. |
chiasma: what is it and when does it occur? | it is he site of crossing over. it is 2 homologous chromosomes not sister chromatids. it occurs early in prophase 1. |
radiation | it is used to kill cancerous cells. it damages cancerous dna more than normal cell dna. |
mutations of genetic diversity. | it widens the gene pool which leads to diversity. |
karyotype | picture of chromosomes lined up in pairs and ordered longest o shortest. t is useful when looking for abnormalities. |
down syndrome and copies of chromosomes. | it has a extra chromosome. A total of 47 chromosomes. #21 has 3 copies of trisomy 21 |
deletion of chromosomes and what disorder I leads to | missing the chromosomes completely and turns into cri du chat |
father of inheritance | gregor mendel |
law of segregation | each parent the mother and the father pass down 1 allele per trait or characteristic. ex the child will get 1 allele from the mother and 1 allele from the father. |
homozygous dominant and recessive | two identical alleles AA is dominant aa is recessive. |
heterozygous | different alleles are paired together. Aa shows dominant trait but can still pass on ability to have a offspring with the recessive trait. |
phenotype vs. genotype | phenotype are the physical characteristics. they are what the allele shows. the genotype is the genetic makeup. they are the actual alleles. |
Sutton-boveri chromosomal theory of inheritance. | chromosomes come in pairs. one comes from the mother and one comes from the father. synapsis is the paring of homologous maternal and paternal chromosomes. these pairs separate into different daughter cells during meiosis. |
physical distance in comparison to recombination. | if they are far apart they will probably split. the closer together they will recombine. |
polygenic inheritance | effects two or more genes on single phenotype trait. Opposite of pleiotrophy |
genetic linkage and how affects assortments of alleles. | genes on the same chromosomes tend to stay together |
pleiotrophy | one gene affects many different characteristics. An example would be sickle cell |
blood type and compatibility. | A=carbohydrates A
B=carbohydrates B
O= no carbohydrates
A,B,O,AB |
incomplete dominance | Three or more genes affect one thing |
inherited disorders | Most inherited disorders are recessive/hidden (ex: Tay-Sachs, Cystic Fibrosis). Dominant are less common because the person wold show the disorder. (ex: Huntington's is dormant for a while, Hypercholesterolemia) |
meiosis 1 , interphase | |
meiosis 1 anaphase | |
meiosis 1 metaphase | |
mitosis, interphase | Chromosomes condense and begin to duplicate, and nucleoli is making proteins. Intermission, where everything is gathered together. |
mitosis, prophase | Chromatin fibers continue to condense for duplication. Nucleoli disappears. Mitotic spindle begins to form (Micro-tubules grow out of chromosomes and begin to move away from each other) (The chromatin looks darker) |
mitosis, prometaphase | Nuclear envelope disappears. Spindle well formed: Micro-tubules elongate to reach sister chromosome. Kinetochores (spindle may attach to) |
mitosis, metaphase | Spindle completely formed. poles at opposite ends. Centromeres align in center. (belt is lined up in the center) |
mitosis, anaphase | sister chromatids separate. Kinetochores proteins move chromatids towards poles via ATP. Chromatids reach opposite poles. |
mitosis, teleophase | Cell elongation continues. Nuclear membrane begins to form around chromosomes. Nuclei appear. Spindle disappears. Cytokineses occur where cytoplasm is divided amongst two cells (cleavage) |
what is meiosis 1? | Very similar to Mitosis and Meiosis II, except: Chromosomes go in pairs, specifically in Anaphase instead of separating: anaphase "X" goes together |