Biology Chapter 7, 8, 9, 10, 12
A human somatic cell has _______ chromosomes?
46
Linked genes are genes that __________.
are on the same chromosome
2 types of chromosomes
autosomes and sex chromosomes
restriction enzymes
cut DNA at specific sequences
The distribution of cytoplasms to daughter cells is accomplished during
cytokinesis
The chromosomal DNA is duplicated which stage of the cell cycle
interphase
Mitosis
interphase, prophase, metaphase, anaphase, telophase
Nondisjuciton
is the failure of chromsome pairs to separate properly during meiosis.
The information by a DNA molecule is in
the order of the nucleotides in the molecule
mutagenesis
the production of mutations
It's difficult to observe individual chromosomes with a light microscope during interphase because
they have uncoiled to form long, thin strands
Nitrogenous bases
thymine, cytosine, adenine, guanine
In a DNA double helix, adenine pairs with _______- and guanine pairs with _______
thymine.......cytosine
The major contribution of sex to evolution has been
to provide greater genetic variation.
Anaphase 1
Homologous chromosomes separate
Telophase 1
2 daughter cells are formed, each daughter cell contains only one chromosome of the homologous pair.
DNA in a single human cell is about ______ long
2 meters (6.5 feet) long
Dogs have a diploid chromosome number of 78. How many chromosomes do their gametes have?
39
If an intestinal cell in a grasshopper contains 12 chromosomes, then a grasshopper sperm cell contains _____ chromosomes.
6
A human skin cell, in prophase of mitosis, contains 46 chromosomes. How many chromosomes contain in total?
92
Telophase 2
A nuclear membrane forms around the chromosomes in each of the 4 new cells.
A karyotype
A picture of all the chromosomes in a cell arranged in pairs
triple code
A set of three-nucleotide-long words that specify the amino acids for polypeptide chains.
ONLY 2 base pairings can form
A to T G to C
2 kinds of base pairings
A to T , G to C
Surprising new evidence has shown that, in some cases, environmental factors can modify chromosomes in such a way that changes the expression of genes without changing genes themselves or any part of the DNA sequence. These modifications are called epigenetic effects. Epigenetic effects can sometimes even be passed from generation to generation. In what way would this kind of "inheritance" be an exception to Mendel's laws?
According to Mendel's laws, the effects of our environment are not passed on to the next generation.
Telophase
After the chromosome seperates, the cell seals off, Final Phase of Mitosis.
Difference between benign tumor and malignant tumor
Benign tumors do not metastasize; malignant tumors do.
Prophase 1
Chromosomes become visible; nuclear envelope breaks down; crossing-over occurs.
Prophase 2
Chromosomes condense, spindles form in each new cell, and spindle fibers attach to chromosomes.
Metaphase 2
Chromosomes line up at the equator.
Metaphase
Chromosomes line up in the middle
Why is the new DNA strand complementary to the 3" to 5" strands assembled in short segments?
DNA polymerase can assemble DNA only in the 5" to 3" direction
recombinant dna
DNA produced by combining DNA from different sources
Alleles
Different forms of a gene
Meiosis goes wrong
Down syndrome caused by an extra copy of chromosome 21, as a result of nondisjunction.
What is the name for this kind of image?
Karyotype
Which allows sexual reproduction to occur generation after generation?
Meiosis
The ABO blood group in humans is an example of _________________ producing 4 phenotypes.
Multiple alleles
Metaphase 1
Paired homologous chromosomes line up across the center of the cell
Which of the following occurs in meiosis but not mitosis?
Pairing of homologous chromosomea
cell division
Process by which a cell divides into two new daughter cells
asexual reproduction
Process by which a single parent reproduces by itself
Meiosis
Prophase 1, Metaphase 1, Anaphase 1, Telophase 1, Prophase 2, Metaphase 2, Anaphase 2, Telophase 2, Cytokinesis
What phase of the cell cycle does DNA replication occur?
S
Ligase
Short segments of newly synthesized DNA are joined into a continuous strand by _____.
biotechnology
The manipulation of living organisms or their components to produce useful products.
Metastasis
The spread of cancer cells beyond their original site
-ACGT
The sticky end of the DNA restriction fragment shown here will pair with a DNA restriction fragment with the sticky end _____.
Sticky ends
The unpaired nucleotides produced by the action of restriction enzymes are referred to as _____.
unambiguous
a codon for on amino acid does not code for any other amino acid
DNA polymerases
a group of enzymes that bond the new nucleotides together
Meiosis
a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.
homologous chromosomes
carry the same genes
Both asexual and sexual reproduction rely on
cell division
Meiosis - me (complicated)
cell division that produces reproductive cells in sexually reproducing organisms
mutation
change in the nucleotide of DNA
Interphase
chromosomes duplicate
Anaphase
chromosomes separate and move to opposite ends of the cell
Human Genome Project
determined the sequence of genes in human DNA
Insulin production
diabetes - caused by insulin deficiency
Cytokinesis
division of the cytoplasm
After DNA replication is completed, _____.
each new DNA double helix consists of one old DNA strand and one new DNA strand
Meiosis only happens in
egg and sperm cells (sexual reproduction)
GgTt pea plants can produce _____ type(s) of gametes, but a ggtt plant can produce _____ type(s) of gametes.
four ... one
The flow of information in a cell proceeds
from DNA to RNA to protein
In general, the frequency with which crossing over occurs between two linked genes depends on _________.
how far apart they are on the chromosome
Telophase
last stage of mitosis
Which term refers to the specific location of a gene on a chromosome?
locus
In humans, the ________ determines the sex of the offspring because ________
male.... the male can contribute an X or Y chromosome.
Plant cells divide by
mitosis followed by cytokinesis by cell plate formation
Prophase
mitotic spindles grow, attach to sister chromatids
redundant
more than one codon for some amino acids
Viruses
not cellular, cannot reproduce on their own, less complex than cells
Mitosis
part of eukaryotic cell division during which the cell nucleus divides
Restriction fragments
pieces of DNA that have been cut into different lengths
4 phases of mitosis
prophase, metaphase, anaphase, telophase
Histones
protein molecules around which DNA is tightly coiled in chromatin
The action of helicase creates
replication forks and replication bubbles
Which of the following is not a function of mitosis in humans?
reproduction of gametes
function of cell division
reproduction, growth and development, healing, sexual reproduction, asexual reproduction
The sex of a human fetus is determined by the....
sex chromosome found in the sperm
nearly universal
shared by all organisms
Anaphase 2
sister chromatids separate
Metaphase 2
sister chromatids separate
Viroids
small circular RNA molecules that infect plants and disrupt their growth
zoonotic disease
spread from animals, caused by viruses, bacteria, 60% of all human diseases originated in other animals
which stage of mitosis is essentially the opposite of prophase in terms of changes within the nucleus?
telophase
Double-helix
two strands of nucleotides wound about each other; structure of DNA
The most common phenotype in a natural population is referred to as the
wild type