Bio chap 4 Flashcards
What is Genetics?
It’s a field in biology where they study how genetic information is passed from one generation of organisms/cells to the next.
What is the full name of DNA?
Deoxyribonucleic Acid
What is DNA?
Genetic information that an individual inherits from his/her parents.
What are the nucleotides in DNA?
- A sugar (deoxyribose)
- A phosphate group
- A base
What are the 4 bases of DNA? Which pairs with which and how many H-bonds are formed?
A - adenine
T - thymine
G - guanine
C - cytosine
A and T with 2 H-bonds
C and G with 3 H-bonds
What is the orginization of eukaryotic chromosomes in order?
- DNA double helix
- DNA wrapped around histone
- Nucleosomes coiled into a chromatin fibre
- Further condensation of chromosome
- Duplication of chromosome
True or False:
There is a relationship between the amount of chromosomes an organism has and it’s complexity.
False
What is a Gamete?
A specialized reproductive cell, either an egg or a sperm. (haploid)
What is a Somatic cell?
A plant/animal body cell
What is the chromatin definition?
A relaxed form of DNA.
What is the definition of chromatids?
A duplication of a chromosome.
Sperm and ovum are _______ (haploid/diploid) cells.
Haploid
Fertilization is a _______ (haploid/diploid) cell.
Diploid
What is the definition of allele?
One of two or more versions of DNA sequence at a given genomic location.
True or False:
22 out of the 23 pairs of chromosomes are homologous.
True
What are autosomes?
True homologous pairs.
Why is the X chromosome bigger than the Y chromosome?
Because it has more genes.
What is a karyotype?
A person’s set of chromosomes.
How are karyptypes made?
A karyotype analysis usually involves blocking cells in mitosis and staining the condensed chromosomes with Giemsa dye. The dye stains regions of chromosomes that are rich in the base pairs Adenine (A) and Thymine (T) producing a dark band.
How are chromosome pairs arranged on karyotypes?
In order of their length, from longest to shortest. The sex chromosomes are organized last.
What are the 3 parts of the cell theory?
- All living things are composed of one or more cells.
- Cells are the smallest unit of living organisms.
- New cells come only from re-existing cells by cell division.
The cell cycle duration depends on …
- The cell type
- The organism
What are the 3 functions of the cell cycle?
- Growth of the organism
- Repair tissues and organs
- Maintenance to replace dead cells
Specific checkpoints:
- Monitor growth
- Ensure the cycle continues or stops appropriatley
What is regulation?
It is the key to preventing uncontrolled and rapid growth.
What are the 3 main stages of Mitosis? Give a short summary of each.
- interphase: growth and intese cell activity
- Mitosis: nucleus and genetic material divide
- Cytokinesis: division of the cell cytoplasm and creation of new cells
How many phases of interphase are there? Give a short summary of each.
- Growth 1 (G-1): major period of growth
- Synthesis (S): DNA (also called chromatin) is replicated
- Growth 2 (G-2): further growth and molecule synthesis
When does DNA replication happen and how does it happen?
It happens during Interphase.
- Double helix unwinds
- Each strand of DNA serves as a template
- Each new double helix contains one original strand and one new strand
What is a chromosome?
A structure in the nucleus that contains DNA.
What is a sister chromatid?
One of two chromosomes that are genetically identical and held together at the centromere.
What is a centromere?
The region where two sister chromatids are held together in a chromosome.
What are the 4 phases of Mitosis?
- Prophase
- Metaphase
- Anaphase
- Telophase
What are the main things that happen in Prophase?
- Nuclear membrane breaks down
- Chromatin condenses into chromosomes
- Chromosomes become visible under a microscope
- Sisiter chromatids are joined together at the centromere
- Centrosomes release spindle fibres
What is a centrosome?
A structore that helps form spindle fibres.
What are spindle fibres?
Microtube structures that facilitate the movement of chromosomes within a cell.
What are the main steps of Metaphase?
- Spindle fibres attach to the centromeres of sister chromatids
- Spindle fibres guide the chromosomes to line up at the equator of the cell