Unit One Test Flashcards
Asexual reproduction
Asexual reproduction generates an offspring that are genetically identical to a single parent
Sexual Reproduction
When two parents contribute genetic information to produce a unique offspring
What are the 4 stages of the cell cycle
G1, G2, S, and M
G1 phase
The stage where the cell is preparing to divide
S phase
The synthesis phase where DNA replication occurs and in this phase the cell duplicates its genetic material to ensure that both daughter cells receive an identical copy of dna
G2 phase
The preparation for mitosis phase, cells are completed during this phase
M phase
The cell division phase, it occurs quickly and involves both mitosis and cytokinesis
What are the 4 stages of mitosis
Prophase, metaphase, anaphase, and telophase
Prophase
The first and longest phase of mitosis, chromatids condensed into a chromosome. The centroiles separate and the spindle begins to form and the nuclear envelope breaks down
Metaphase
Chromosomes line up across the center of the cell, each is connected to a spindle fiber at its centromere
Telophase
The chromosomes gather at opposite ends of the cell and lose their distinct shapes. Two new nuclear envelope will form
Cytokinesis
It’s the 2nd stage of a eukaryote where the cytoplasm divides
Why is cell growth regulation important? What can happen if cell growth is not regulated
Its important for the development in tissue repair and maintaining body functions by replacing old or damaged cells
What are the 4 stages in meiosis I
Prophase I, Metaphase I, Anaphase I, and Telophase I
Prophase I
In prophase I of meiosis, homologous chromosomes pair up and exchange genetic material through crossing over, increasing genetic diversity.
Metaphase I
In metaphase I of meiosis, homologous chromosome pairs align along the metaphase plate, with spindle fibers attaching to their centromeres.
Anaphase I
In anaphase I of meiosis, homologous chromosome pairs are separated and pulled to opposite poles of the cell by spindle fibers.
Telophase I
In telophase I of meiosis, chromosomes reach opposite poles, the nuclear membrane may reform, and the cell prepares to divide through cytokinesis, resulting in two haploid daughter cells.
What are the 4 stages in meiosis II
Prophase II, Metaphase II, Anaphase II, and telophase II
Prophase II
In prophase II of meiosis, the nuclear envelope breaks down (if it reformed), spindle fibers reappear, and chromosomes condense in the two haploid daughter cells.
Metaphase II
In metaphase II of meiosis, chromosomes line up along the metaphase plate, with spindle fibers attaching to their centromeres.
Anaphase II
In anaphase II of meiosis, sister chromatids are pulled apart by spindle fibers and move toward opposite poles of the cell.
Telophase II
In telophase II of meiosis, chromosomes reach opposite poles, the nuclear membrane reforms, and the cells undergo cytokinesis, resulting in four haploid daughter cells.
What are three units that make up a nucleic acid
The three units that make up a nucleic acid are a phosphate group, a pentose sugar and a nitrogenous base
Which scientists helped contribute to the discovery of dna
Friedrich Miescher, Phoebus Levene, Erwin Chargaff, Rosalind Franklin, Maurice Wilkins, and James Watson & Francis Crick all contributed to the discovery of DNA.
Whats the structure of dna? Are both strands identical? Are they parallel or antiparallel?
DNA has a double helix with two antiparallel strands that are complementary, not identical. Adenine pairs with thymine, and cytosine pairs with guanine.
One strand runs to 5’ to 3’ and the other 3’ to 5”
Which four nitrogen bases are linked to dna? Which ones pair together?
The four nitrogen bases in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G). Adenine pairs with thymine, and cytosine pairs with guanine.
How does dna replication occur?
DNA replication involves unwinding by helicase, followed by DNA polymerase adding nucleotides. The leading strand is copied continuously, while the lagging strand is copied in fragments.
How is RNA different from DNA
RNA is single-stranded, contains ribose sugar, and has uracil (U) instead of thymine (T). DNA is double-stranded, uses deoxyribose sugar, and has thymine (T).
What are three different forms of RNA
The three forms of RNA are mRNA (carries genetic info), tRNA (transfers amino acids), and rRNA (makes up ribosomes).
Which four nitrogen bases are linked to rna? Which ones pairs up?
The four nitrogen bases in RNA are adenine (A), uracil (U), cytosine (C), and guanine (G). Adenine pairs with uracil, and cytosine pairs with guanine.
What is protein synthesis?
Protein synthesis is the process where mRNA is transcribed from DNA and then translated into a protein at the ribosome.
Explain how transcription happens in the nucleus of the cell
During transcription, RNA polymerase unzips the DNA and synthesizes a complementary mRNA strand using one of the DNA strands as a template. The mRNA then leaves the nucleus and moves to the cytoplasm for translation.
Explain how transcription happens in the cytoplasm of the cell
where mRNA is decoded by ribosomes to synthesize proteins.
What are two types of mutations, explain each type
- Point Mutation – A change in a single DNA base.
- Frameshift Mutation – Insertion or deletion of nucleotides, shifting the reading frame.
Explain the antiparallel nature of the DNA molecule
The DNA molecule is antiparallel because its two strands run in opposite directions: one strand is oriented 5’ to 3’, while the complementary strand runs 3’ to 5’.
What are the steps in the semiconservative replication of the DNA molecule
- Unwinding – Helicase separates DNA strands.
- Priming – Primase adds RNA primers.
- Elongation – DNA polymerase adds nucleotides.
- Sealing – Ligase joins fragments.
What is chromosomal mutations
Large mutations as they involve changes in whole chromosomes. They often involve the addition or deletion of an entire chromosome
