Biology Finals Review Flashcards
questions from bio tests
what is the full name of DNA?
Deoxyribonucleic Acid
segments of DNA which code for specific proteins are called __________
nucleotides
DNA may coil and condense into visible structures called ___________.
helixes
What two nitrogenous bases are purines?
adenine and guanine
what 2 nitrogenous bases are pyrimidines?
cytosine and thymine
adenine always pairs with __________
thymine
guanine always pairs with __________
cytosine
what chemical bond holds the nitrogenous base pairs together?
hydrogen bonds
the rungs or steps of the ladder would be the _____________
nitrogenous bases
the sides of the ladder would be ____________
the sugar phosphate backbone
what enzyme unzips the DNA molecule?
Helicase
what enzyme builds the new DNA strands using the original strands as templates?
DNA polymerase
DNA replicates through what process?
semi-conservative replication
which of the following enzymes is not involved in DNA replication as the others?
a. helicase
b. dna polymerase
c. dna ligase
c. phosphatase
c. phosphatase
What is the function of DNA polymerase III?
it adds single nucleotides to the growing DNA strands.
When DNA replication starts _______________.
the hydrogen bonds between the nucleotides of 2 strands break.
the elongation of the leading strand during DNA synthesis ____________.
occurs in the 3’-5’ direction
eukaryotes differ from prokaryotes in the mechanisms of DNA replication due to _______________.
having telomeres at the end of DNA
which of the following enzymes remove supercoiling in replicating DNA ahead of the replication?
topoisomerase
when does DNA replication occur during the cell cycle?
S phase
DNA replication in prokaryotes occurs in the ____________, and due to their circular DNA the enzyme __________ is not needed as seen in eukaryotes due to its linear double strand structure.
cytoplasm; telomerase
a human cell containing 22 autosomes and a XY chromosome is ___________.
a somatic cell of a male
meiosis ii is similar to mitosis in that ___________.
sister chromatids separate during anaphase
metaphase of meiosis i and meiosis ii differ in that _________
homologous chromosome line up in meiosis i and duplicated chromosomes line up in meiosis ii
a gamete cell of an alligator has 16 chromosomes. What is the total number of chromosomes that should be present in a stomach cell of the same alligator?
32 chromosomes
compared to the # of chromosomes contained in a body cell, how many chromosomes would normally be contained in a gamete?
half as many chromosomes
both male and female gametes are created during the process of meiosis. the formation of male gametes or sperm is called spermatogenesis. After telophase ii of spermatogenesis, there would be ____________ male gametes created that are all genetically __________.
4; different/unique
germ cells in humans contain ______ chromosomes and an example is _______
23; sperm cells
during which phase of meiosis does the nuclear membrane reform around chromosomes?
telophase ii
at which stage of meiosis do chromatids separate and become daughter chromosomes?
anaphase ii
the process in which haploid gametes are formed in diploid organisms is called__________.
meiosis
a human cell containing 44 autosomes and two x chromosomes is ____________?
a somatic cell of a female
which cells of the human body are made through the process of meiosis?
gametes
the fertilized egg of a human containes how many chromosomes?
46 chromosomes
which 2 cells would be more genetically similar to each other?
a. 2 gametes made by the same person
b. 2 somatic cells made by the same person
c. 2 eggs made by the same woman
d. 2 sperm cells produced by the same man
b. 2 somatic cells made by the same person
which of the following happens when a cell divides?
a. the cells volume increases
b. it becomes more difficult for the cell to get rid of wastes
c. each daughter cell recieves its own copy of the parent cells dna
d. it becomes more difficult for the cell to get enough oxygen and nutrients
c. each daughter cell receives its own copy of the parent cells’s DNA
the process by which a cell divides into 2 daughter cells is called
mitosis
an advantage of sexual reproduction over asexual reproduction is that sexual reproduction __________.
provides genetic diversity
when during the cell cycle are chromosomes visible?
only during cell division
during normal mitotic cell division, a parent cell that has 4 chromosomes will produce 2 daughter cells, each containing __________.
4 chromosomes
which pair includes a phase of the cell cycle and a cellular process that occurs during that phase?
a. G1 phase, DNA replication
b. G2 phase, preparation for mitosis
c. S phase, cell division
d. M phase, cell growth
b. G2 phase, preparation for mitosis
when during the cell cycle is a cell’s DNA replicated?
S phase
which event occurs during interphase?
a. the cytoplasm divides
b. centrioles duplicate
c. spindle fibers begin to form
d. centromeres divide
b. centrioles duplicate
which of the following is a correct statement about the events of the cell cycle?
a. little happens during the G1/2 phases
b. DNA replicates during the cytokinesis
c. the M phase is usually the longest phase
d. interphase consists of the G1, S phase, and G2 phases
d. interphase consists of the G1, S phase, and G2 phases
During Mitosis, how many times does a cell divide?
once
how many new cells does the cell cycle create?
2 new cells
when during the cell cycle are chromosomes visible?
only during cell division
what structure forms in prophase which helps the chromosomes move?
spindle fibers
which phase of the cell cycle is characterized by a non dividing cell?
interphase
what is the period of cell growth and development between mitotic divisions?
interphase
during what phase of mitosis do centromeres divide and the chromosomes move toward their opposite poles?
anaphase
in a chromosome pair connected by a centromere, what is each individual chromosome called?
a chromatid
offspring produced during asexual reproduction are ___________ to their parents.
identical
a typical human cell contains 46 chromosomes. after mitosis and cytokinesis, each of the two new cells formed from the original cell have how many chromosomes?
23 chromosomes